Synthesis of functionalized triazatriangulenes for application in photo- Switchable self-assembled monolayers

FULL PAPER

DOI: 10.1002/ejoc.201000650

Synthesis of Functionalized Triazatriangulenes for Application in Photo-

Switchable Self-Assembled Monolayers

Jens Kubitschke,^[a]Christian Näther,^[b]and Rainer Herges*^[a]

Keywords: Monolayers / Photoswitching / Self-assembly / Molecular electronics / Triazatriangulenes / Azobenzenes

Various triazatriangulenes are synthesized by nucleophilic

attack at the central C atom of triazatriangulenium ions. The

molecular functions, especially azobenzenes, are fixed via an

ethynyl linker by in situ deprotection of trimethylsilyl-

alkynes. The structure of two of these molecules is further

investigated by X-ray crystallography. The photo-induced

trans/cis-isomerization of the azobenzene substituted deriva-

tives is analyzed in solution and shows great promise for the

preparation of switchable functionalized monolayers, as the

triazatriangulenes are known for their self-assembly on gold

surfaces.^[1]

densely packed monolayers.^[11]Only azobenzenes next to

domain boundaries or defects in the monolayer have

enough space to switch.^[12]To overcome this problem the

monolayers were “diluted” with short-chain alkane thiols

to create the required free volume.^[11,13–15]Disadvantage of

this approach is the stochastical distribution of the azo-

benene units and thus the loss of an ordered surface. More-

over, phase segregation has been observed and the cluster-

ing of azobenzene-containing thiols gradually leads to the

steric problem described above.^[16]Another promising ap-

proach is the use of tripodal linker systems.^[17–22]These lin-

kers include three thiol groups for the fixation to the surface

and cover a surface area that is sufficient to allow the con-

formational switching of the azobenzene function.

We recently presented a novel method to prepare ordered

monolayers without using thiols. The “platform approach”

is a modular, molecular system including a pedestal with a

high affinity to gold and a reactive center in the middle

which allows easy attachment of various functional groups

perpendicular to the surface.^[1,12,23]The triazatriangulenium

(TATA) ion turned out to be an ideal molecular platform

towards this end. It forms well ordered SAMs on Au(111).

A number of carbanionic compounds can be attached to

the carbocationic center of the TATA ion by simple polar

C–C bond formation. Moreover, TATA platforms in dif-

ferent sizes can be easily prepared by variation of the alkane

substituents at the three angular nitrogen atoms. Thus, by

changing the size of the platforms the distance between the

functional groups within the monolayer can be tuned.^[1]

Using propyl or larger substituents the free volume should

be sufficient to allow the photo-induced isomerization of

an attached azobenzene function.

Introduction

Rational approaches for the controlled functionalization

of surfaces are the prerequisites to achieve more sophisti-

cated applications such as data storage, molecular elec-

tronics, surface property switching, or directed motion on

surfaces.^[2–7]One of the most frequently used and simplest

methods to attach organic molecules to a metal surface is

the use of an alkane spacer and a terminal thiol group

which has a high affinity in particular to gold. Self-as-

sembled monolayers (SAMs) form spontaneously upon im-

mersion of the gold target into a solution of the thiol substi-

tuted functional molecule.^[2]A multitude of functionalities

including azobenzenes have been immobilized as SAMs on

Cu, Ag, and Au surfaces. The sulfur binds strongly to the

metal and in a densely packed monolayer the alkane spa-

cers with the functional molecules stand more or less up-

right like bristles in a brush. Azobenzenes are frequently

used as functional molecules because they undergo a revers-

ible trans/cis-isomerization upon irradiation. Upon expo-

sure to UV light (usually 365 nm) the thermodynamically

more stable trans configuration isomerizes to the cis form.

The isomerization back to the trans form is achieved by

irradiation with visible light or by heating.^[8]Whereas

switching in solution usually is quite effective, monolayers

prepared by the alkanethiol method (with one exception^[9])

exhibit no or moderate switching rates.^[10]Sterical hin-

drance has been blamed to prevent isomerisation within the

[a] Otto-Diels-Institut für Organische Chemie,

Christian-Albrechts-Universität zu Kiel,

Otto-Hahn-Platz 4, 24098 Kiel, Germany

Fax: +49-0-431-880-1558

E-mail: rherges@oc.uni-kiel.de

[b] Institut für Anorganische Chemie,

Herein, we report preparative procedures that allow the

covalent attachment of various groups to the cationic center

of triazatriangulenium salts. The structures of two substi-

tuted triazatriangulenes, the phenylethynyl compound 4a

View this journal online at

Christian-Albrechts-Universität zu Kiel,

Otto-Hahn-Platz 6/7, 24098 Kiel, Germany

Supporting information for this article is available on the

WWW under http://dx.doi.org/10.1002/ejoc.201000650.

wileyonlinelibrary.com

Eur. J. Org. Chem. 2010, 5041–5055

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J. Kubitschke, C. Näther, R. Herges

FULL PAPER

and the phenyl derivative 3a were determined by single-

Acetylene is coupled to the platform by simply reacting

crystal X-ray crystallography. The synthesis of 16 different sodium acetylide with the TATA ion at elevated tempera-

azobenzene functionalized platforms is described and the tures. The terminal alkyne 2a/b is a potential precursor for

photostationary equilibria upon irradiation with 365 and further derivatization by coupling reactions (e.g. Sonoga-

440 nm light in solution is analysed for 8 representative ex- shira, Glaser-Hay) or click-chemistry. The phenyl-substi-

amples. The half life of the cis isomers with respect to the tuted triazatriangulene 3a/b is formed by reaction of phen-

thermal back isomerization was determined for these com- yllithium with TATA in THF. Compound 3a forms single

pounds.

crystals by recrystallization from diethyl ether, as well as

compound 4a, which is synthesized by deprotonation of

phenylacetylene with a 2.5  n-butyllithium solution and

subsequent reaction with the TATA ion 1a. A more general

approach which is compatible to a multitude of functionali-

ties, especially azobenzenes, is to use a TMS protected alk-

yne. In situ deprotection and coupling with the cationic

center of the TATA ion 1a/b is achieved with a base prefer-

entially potassium hydroxide. Reactions times are drasti-

cally decreased if a strong ultra sound source (e.g., Branson

Sonifier W-450) is used (Scheme 1).

Results and Discussions

Syntheses of Functionalized Triazatriangulenes

The triazatriangulenium ions 1a/b were synthesized ac-

cording to a procedure of Laursen and Krebs.^[24]According

to previous STM experiments extended alkane chains at the

three angular nitrogen atoms enhance the solubility and

favour the formation of ordered monolayers.^[1]Molecular

functions are attached to the central C atom of the TATA

ions by nucleophilic attack of sp (ethynyl) and sp²(phenyl)

carbanions.

The TMS-ethynyl-substituted azobenzenes 20–27

(Scheme 2) are synthesized using the condensation reaction

of anilines and nitroso compounds.^[25]The nitrosoarenes

are obtained by oxidation of aniline derivatives with

Scheme 1. Overview of synthesized triazatriangulenes 2–16a/b.

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Triazatriangulenes for Photo-Switchable Self-Assembled Monolayers

Oxone^®[26]or by reduction of nitroarenes with tin.^[27]As responding azobenzenes by condensation with the respec-

most of the nitrosoarenes are labile, purification was not tive aniline derivative in acetic acid.^[26]In general, 4-[(tri-

attempted, and they are immediately converted into the cor- methylsilyl)ethynyl]aniline (19), which is synthesized by

Sonogashira reaction of 4-iodoaniline (17) and (trimethyl-

silyl)acetylene (18),^[28]is used for the reaction with the cor-

responding nitrosoarene. However, oxidation of compound

19 to the nitroso derivative 33 is also appropriate, even

though the yields are low.

Particularly in cases where the nitroso derivatives cannot

be easily synthesized from commercially available com-

pounds, oxidation of 19 to the nitroso derivative 33 is pre-

ferred. For example, 4-methoxyaniline 31 as well as the deu-

terated derivative 32 are converted into the corresponding

azobenzenes 34 and 35 (Scheme 3) by condensation with 4-

[(trimethylsilyl)ethynyl]nitrosobenzene (33). The deuterated

4-methoxyaniline 32 is synthesized from 4-nitrofluoro-

benzene 28 by nucleophilic aromatic substitution with an

alkaline solution of deuterated methanol.^[29]The reduction

of the obtained nitro compound to the corresponding

amine is carried out using sodium borohydride and cop-

per(II) acetylacetonate as a catalyst.^[30]

To increase the distance between the molecular functions

and the TATA platform (and accordingly the surface) a

phenyl ring was introduced as an additional spacer. Bi-

phenyl (36) can be substituted in 4,4Ј position by an iodo

as well as a nitro group in one step.^[31]Less than equimolar

amounts of iodine must be used because otherwise an in-

separable mixture of 4,4Ј-diiodo-1,1Ј-biphenyl and 37 is

formed.^[32]The unsymmetrically substituted biphenyl 37 is

reduced to the amine using tin(II) chloride.^[33]The TMS

Scheme 2. Synthesis of TMS-ethynyl-substituted azobenzenes 20–

27.

protected acetylene is attached by Sonogashira coupling^[28]

Scheme 3. Synthesis of (E)-1-(4-methoxyphenyl)-2-{4-[(trimethylsilyl)ethynyl]phenyl}diazene (34) and the deuterated derivative 35.

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J. Kubitschke, C. Näther, R. Herges

FULL PAPER

Scheme 4. Synthesis of (E)-1-phenyl-2-(4-{4-[(trimethylsilyl)ethynyl]phenyl}phenyl)diazene (40).

yielding compound 39. The corresponding azobenzene 40 is

finally obtained by condensation with nitrosobenzene. The

attachment of 40 to the TATA platform 1b proceeds as de-

scribed above (Scheme 4).

Crystal Structures of 3a and 4a

Upon recrystallization from diethyl ether, compounds 3a

and 4a formed single crystals suitable for X-ray single crys-

tal structure analysis. The phenyl-substituted triazatriangul-

ene 3a crystallizes orthorhombic in space group Pnma with

the molecule located on a crystallographic mirror plane.

This compound contains additional diethyl ether as solvent

also located on a mirror plane. In contrast to the unsubsti-

tuted cation 1a,^[24]the central C-atom C1 is sp³-hybridized

and thus the platform is no longer planar. This C-atom is

shifted by 0.740 Å from a least-square plane calculated

through the three N atoms and the three six-membered

rings (Figure 1, top). The phenyl ring is oriented exactly

perpendicular to the platform (dihedral angle: 90°) (Fig-

ure 1, top) and is exactly eclipsed to one of the three propyl

groups (Figure 1, bottom). However, one can expect that

Figure 1. Crystal structure of compound 3a with view along (top)

and onto (bottom) the TATA platform.

the rotational barrier is rather low and can easily be over-

compensated by packing effects (Figure 1, bottom).

Compound 4a crystallizes monoclinic in space group C2/

c with all atoms located in general positions. As in 3a the

central C-atom is shifted out of the molecular plane (devia- angle between this substituent and the platform amounts to

tion: 0.998 Å). The phenylethynyl substituent is oriented al- 84.7° (Figure 2, top). Moreover, this substituent is nearly

most perpendicular to the TATA platform and the dihedral eclipsed to one of the three propyl substituents.

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Triazatriangulenes for Photo-Switchable Self-Assembled Monolayers

In the NMR spectrum, a new set of signals appears after

irradiation of the trans isomer with 365 nm. Up to 80% cis-

isomer is formed. The cis to trans isomer ratio can be easily

1

determined by intergration of the H NMR signals of both

isomers. The half life of the thermal back isomerization at

ambient conditions was determined by following the de-

crease of the signals of the cis-isomer over several days and

is shown in Table 1. As expected, the introduction of elec-

tron withdrawing as well as electron donating substituents

to the azobenzene system in para position increases the re-

action rate of the thermal back isomerization.^[36–41]

Table 1. Percentage of the cis-isomers formed by irradiation with

365 nm in the photostationary equilibrium and half life of thermal

back isomerization determined by NMR of azobenzene substituted

triazatriangulenes in [D₈]toluene at room temperature.

cis_max

t_1/2[min]

6a

73%

80%

42%

37%

74%

72%

47%

2771

2999

1486

1135

910

1437

942

6b

7b

8a

8b

9b

12b

15b

2047

Figure 2. Crystal structure of compound 4a with view along (top)

and onto (bottom) the TATA platform.

Conclusions

In summary, several triazatriangulenes 2–16a/b were syn-

thesized by nucleophilic attack at the central C atom of the

TATA cations 1a/b. Various functionalities, including azo-

benzenes, with different spacer lengths were attached per-

pendicular to the plane of the platform like a floor lamp on

a pedestal. The reversible photoisomerization of the azo-

benzene derivatives was proven by UV/Vis and NMR spec-

troscopy in solution. The TATA platform in combination

with the click-type perpendicular attachment of functional

groups with different linear spacer groups represents a

modular and flexible system to design and prepare sophisti-

cated functional monolayers.^[1,23]Preliminary experiments

revealed that the Azo TATA molecules form ordered mono-

layers on Au(111) and retain their switching capability. De-

tails will be published in a forthcoming publication.

Photoswitching

In solution, the isomerization of the azobenzene deriva-

tives 6–16a/b (Figure 3) was observed by UV/Vis and NMR

spectroscopy. Upon irradiation with a high pressure mer-

cury lamp and a band-pass filter (365 nm), the πǞπ* tran-

sition band in the UV/Vis spectrum decreases and the n-π*

transition band increases, which indicates the formation of

the cis-isomer.^[34–35]The reisomerization was induced by ir-

radiation with light of 440 nm. The conversion, however, is

not complete and leads to a photostationary equilibrium.

Experimental Section

General Remarks: TLC was performed with TLC plates (Polygram

Sil G/UV₂₅₄), Fa. Macherey–Nagel. Column chromatography was

performed with silica gel 60 (0.04–0.063 mm) or aluminium oxide

60 basic (0.063–0.2 mm), Fa. Merck. NMR spectra were recorded

using a Bruker DRX 500 [¹H NMR (500.1 MHz), ¹³C NMR

(125.8 MHz)] with tetramethylsilane (δ_H= 0.00 ppm) and CDCl₃

(δ_C= 77.01 ppm) as internal standard. For the assignment of the

NMR signals and the numbering of the corresponding carbon

atoms see Supporting Information. Mass spectra were recorded on

a MAT 8230 (EI, 70 eV), Fa. Finnigan. IR spectra were recorded

with a Perkin–Elmer 1600 series FT-IR spectrometer, using a

golden-gate-diamond-ATR unit A531-G. UV/Vis spectra were re-

corded with a Lambda 14 UV/Vis spectrometer, Fa. Perkin–Elmer.

Figure 3. UV/Vis absorption spectra of 6a in toluene, before and

after irradiation with 365 nm and 440 nm, respectively.

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5045

J. Kubitschke, C. Näther, R. Herges

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Elemental analysis were recorded with a CHNSO elemental ana-

lyser EURO EA 3000 series, Fa. Euro Vector. Photo-irradiation

was performed with a UV light source UV-P 250 C, Fa. Panacol-

Elosol, using band-pass filters LC-365BP20–25 and LC-440BP10–

25, Fa. Laser Components.

General Method 2. Azobenzene-Substituted Triazatriangulenes:

Powdered KOH (in excess) was added to a solution of trimethyl-

silylethynyl-substituted azobenzene (1 equiv.) in 20–40 mL THF

under nitrogen. The mixture was sonicated for 20–60 min at 0 °C

using a Branson Sonifier W-450. After adding 4,8,12-tri-n-propyl-

4,8,12-triaza-triangulenium tetrafluoroborate 1a (1 equiv.) or

4,8,12-tri-n-octyl-4,8,12-triazatriangulenium tetrafluoroborate 1b

(1 equiv.) respectively, the mixture was sonicated for a further

period of 1.5–5 h at 0 °C. Afterwards, the mixture was poured into

100 mL water. The layers were separated and the aqueous layer was

extracted with diethyl ether. The combined organic layers were

dried with MgSO₄and filtered. After evaporating the solvents, the

residue was dissolved in dichloromethane and filtered through a

short column of basic aluminium oxide. The solvent was evapo-

rated and the resulting orange residue recrystallized from diethyl

ether or ethanol, respectively.

Crystal Structure Determination: Data measurements were per-

formed with an imaging plate diffraction system (IPDS-1) with

Mo-K_αradiation from STOE & CIE. The structure solutions were

done with direct methods using SHELXS-97 and structure refine-

ments were performed against F²using SHELXL-97. All non hy-

drogen atoms were refined with anisotropic displacement param-

eters. All hydrogen atoms were positioned with idealized geometry

and were refined with fixed isotropic displacement parameters

using a riding model. 3a contain a small amount of solvent disor-

dered around a center of inversion. Because no reasonable structure

model was found the data were corrected for disordered solvent

using the SQUEEZE option in Platon (Table 2).

(E)-1-Phenyl-2-{4-[(trimethylsilyl)ethynyl]phenyl}diazene (20): Ni-

trosobenzene (1.07 g, 10.0 mmol) was added to a solution of 4-

[(trimethylsilyl)ethynyl]aniline (19) (1.89 g, 10.0 mmol) in 40 mL

acetic acid and stirred for 16 h. The resulting precipitate was sepa-

rated by filtration and recrystallized from ethanol to yield 20

(1.66 g, 60%) as an orange solid. ¹H NMR (500.1 MHz, CDCl₃,

Table 2. Crystallographic data for 3a and 4a.

Compound

3a

4a

Formula

C₃₈H₄₅N₃O

559.77

orthorhombic

Pnma

14.473(1)

14.734(1)

14.894(1)

–

C₃₆H₃₅N₃

509.67

monoclinic

C2/c

26.175(2)

15.096(1)

18.625(2)

124.15 (1)

6090.8(7)

170

MW [gmol^–1]

Crystal system

Space group

a [Å]

3

25 °C): δ = 7.92 (d, J = 8.1 Hz, 2 H, 13-H, 17-H), 7.86 (d, ³J =

8.8 Hz, 2 H, 7-H, 9-H), 7.60 (d, ³J = 8.8 Hz, 2 H, 6-H, 10-H), 7.46–

7.55 (m, 3 H, 14-H, 15-H, 16-H), 0.28 (s, 9 H, 1-H, 2-H, 3-H) ppm.

¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 152.63 (C-12), 151.91

(C-8), 132.81 (C-6, C-10), 131.27 (C-15), 129.14 (C-14, C-16), 125.8

(C-11), 122.96 (C-13, C-17), 122.79 (C-7, C-9), 104.64 (C-5), 97.04

(C-4), –0.08 (C-1, C-2, C-3) ppm. MS (EI, 70 eV): m/z (%) = 278

(93), 263 (17), 201 (16), 173 (100), 158 (50), 143 (23), 105 (22). IR

b [Å]

c [Å]

β [°]

V [Å³]

3176.1(4)

170

T [K]

Z

4

8

(ATR): ν = 3057 (w), 2960 (m), 2903 (m), 2149 (s), 1594 (m), 1492

˜

D_calc[gcm^–3]

µ [mm^–1]

θ_max/deg

1.171

0.070

28.1

1.112

0.065

26.0

(m), 1482 (m), 1396 (m), 1298 (m), 1247 (s), 1220 (s), 1151 (s), 1105

(m), 1000 (m), 837 (vs), 759 (s), 683 (s), 664 (s), 563 (s), 536 (s),

505 (s) cm^–1. UV (toluene): λ_max(lgε) = 451 (3.09), 344 (4.44) nm.

C₁₇H₁₈N₂Si (278.12): calcd. C 73.33, H 6.52, N 10.06; found C

73.23, H 6.75, N 9.83.

Measured reflections

Unique reflections

Reflections [F_oϾ 4σ(F_o)] 3328

25196

3981

18150

5978

4379

Parameters

R_in_[a_t_]

212

353

(E)-1-(4-Iodophenyl)-2-{4-[(trimethylsilyl)ethynyl]phenyl}diazene

(21): 4-Iodonitrosobenzene^[27](885 mg, 3.80 mmol) was added to a

solution of 4-[(trimethylsilyl)ethynyl]aniline (19) (718 mg,

3.80 mmol) in 40 mL acetic acid and stirred for 16 h. The resulting

precipitate was separated by filtration and recrystallized from etha-

nol to yield 21 (1.00 g, 65 %) as an orange solid. ¹H NMR

0.0495

0.0428

0.1217

1.034

0.0391

0.0486

0.1307

1.021

R₁[F_oϾ 4σ(F_o)]

[b]

wR₂[all data]

GOF

∆ρ_max, ∆ρ_min[eÅ^–3]

0.267–0.227

0.281/–0.255

[a] R₁= ∑||F_o| – |F_c||/∑|F_o|. [b] wR₂= [∑[w(F_o– F_c²)²]/∑[w(F_o) ]]^1/2

.

3

2

2 2

(500.1 MHz, CDCl₃, 25 °C): δ = 7.86 (d, J = 8.5 Hz, 2 H, 14-H,

3

16-H), 7.85 (d, J = 8.4 Hz, 2 H, 7-H, 9-H), 7.64 (d, J = 8.5 Hz,

3

2 H, 13-H, 17-H), 7.60 (d, J = 8.4 Hz, 2 H, 6-H, 10-H), 0.28 (s, 9

H, 1-H, 2-H, 3-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ

= 152.02 (C-12), 151.81 (C-8), 138.52 (C-14, C-16), 132.95 (C-6, C-

10), 126.26 (C-11), 124.62 (C-13, C-17), 122.99 (C-7, C-9), 104.66

(C-5), 98.12 (C-15), 97.51 (C-4), 0.00 (C-1, C-2, C-3) ppm. MS (EI,

70 eV): m/z (%) = 404 (89), 389 (16), 231 (24), 203 (53), 201 (25),

CCDC-775476 (for 3a) and CCDC-775477 (for 4a) contain the

supplementary crystallographic data for this paper. These data can

be obtained free of charge from The Cambridge Crystallographic

Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

General Method 1. Trimethylsilylethynyl-Substituted Azobenz-

enes:^[25]A solution of Oxone^®(2 equiv.) in water was added to a

solution of the respective aniline (1 equiv.) in dichloromethane. Af-

ter stirring for 0.5 to 5 h (TLC monitoring) at room temperature,

the layers were separated. The aqueous layer was extracted twice

with dichloromethane. The combined organic phases (usually

green) were washed with 1  HCl, saturated NaHCO₃solution,

H₂O, saturated NaCl solution and dried with MgSO₄. Removal of

the solvent yielded the corresponding nitrosoarene, which was used

in the next step without further purification. An equimolar amount

of an aniline derivative was dissolved in 40 mL acetic acid. After

adding the nitrosoarene, the mixture was stirred for 2–24 h. The

resulting orange precipitate was separated by filtration and recrys-

tallized from ethanol.

173 (100), 158 (55), 145 (24), 143 (29). IR (ATR): ν = 3082 (w),

˜

2957 (m), 2898 (m), 2159 (m), 1593 (m), 1566 (m), 1491 (m), 1473

(m), 1393 (m), 1251 (s), 1225 (s), 1154 (m), 1100 (m), 1050 (m),

1002 (s), 834 (vs), 759 (s), 556 (s) cm^–1. UV (toluene): λ_max(lgε) =

448 (3.23), 360 (4.53) nm. C₁₇H₁₇IN₂Si (404.02): calcd. C 50.50, H

4.24, N 6.93; found C 49.68, H 3.89, N 6.71.

(E)-4-({4-[(Trimethylsilyl)ethynyl]phenyl}diazenyl)benzonitrile (22):

Following the general method 1, a solution of Oxone^®(20.8 g,

33.9 mmol) in 150 mL water was added to a solution of 4-amino-

benzonitrile (2.00 g, 16.9 mmol) in 40 mL dichloromethane and the

mixture was stirred for 2.5 h. The crude product was purified by

column chromatography (silica gel, dichloromethane) yielding a

yellow solid (1.12 g, 50%).

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Triazatriangulenes for Photo-Switchable Self-Assembled Monolayers

The nitroso compound (660 mg, 5.00 mmol) was added to a solu-

tion of 4-[(trimethylsilyl)ethynyl]aniline (19) (945 mg, 5.00 mmol)

in 30 mL acetic acid and stirred for 3.5 h. The resulting precipitate

was separated by filtration and recrystallized from ethanol to yield

22 (987 mg, 65 %) as an orange solid. ¹H NMR (500.1 MHz,

346 (70), 331 (17), 201 (19), 173 (100), 158 (32), 145 (41), 143 (15),

126 (11). IR (ATR): ν = 3056 (w), 2965 (m), 2904 (m), 2162 (m),

˜

1594 (m), 1490 (m), 1409 (m), 1317 (s), 1255 (s), 1223 (s), 1165 (s),

1128 (s), 1102 (s), 1063 (s), 1011 (s), 837 (vs), 763 (s), 674 (s), 601

(s), 553 (s) cm^–1. UV (toluene): λ_max(lgε) = 453 (3.14), 346 (4.49)

CDCl₃, 25 °C): δ = 7.98 (d, ³J = 8.7 Hz, 2 H, 13-H, 17-H), 7.90 (d, nm. C₁₈H₁₇F₃N₂Si (346.11): calcd. C 62.41, H 4.95, N 8.09; found

3

³J = 8.7 Hz, 2 H, 7-H, 9-H), 7.81 (d, J = 8.7 Hz, 2 H, 14-H, 16-

C 62.82, H 5.20, N 8.10.

3

H), 7.62 (d, J = 8.7 Hz, 2 H, 6-H, 10-H), 0.28 (s, 9 H, 1-H, 2-H,

(E)-1-(4-Hexylphenyl)-2-{4-[(trimethylsilyl)ethynyl]phenyl}diazene

(25): Following the general method 1, a solution of Oxone^®(19.5 g,

31.7 mmol) in 160 mL water was added to a solution of 4-[(trimeth-

ylsilyl)ethynyl]aniline (19) (3.00 g, 15.9 mmol) in 60 mL dichloro-

methane and the mixture was stirred for 5 h. The crude product

was purified by column chromatography (silica gel, cyclohexane/

dichloromethane, 3:1) yielding a green solid (1.01 g, 31%).

3-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 154.49 (C-

12), 151.60 (C-8), 133.25 (C-14, C-16), 132.93 (C-6, C-10), 127.15

(C-11), 123.43 (C-13, C-17), 123.25 (C-7, C-9), 118.40 (C-18),

114.23 (C-15), 104.35 (C-5), 98.19 (C-4), –0.13 (C-1, C-2, C-3) ppm.

MS (EI, 70 eV): m/z (%) = 303 (67), 288 (19), 260 (9), 201 (11), 173

(100), 158 (65), 145 (15), 143 (28), 102 (33). IR (ATR): ν = 3095

˜

(w), 3050 (w), 2959 (m), 2906 (w), 2228 (m), 2158 (m), 1594 (m),

1489 (m), 1449 (m), 1407 (m), 1250 (s), 1227 (s), 1152 (m), 1135

(m), 1101 (m), 1007 (m), 834 (vs), 756 (s), 637 (s), 564 (s), 473 (s)

cm^–1. UV (toluene): λ_max(lg ε) = 457 (3.19), 360 (4.52) nm.

C₁₈H₁₇N₃Si (303.12): calcd. C 71.25, H 5.65, N 13.85; found C

71.04, H 5.72, N 14.16.

The nitroso compound 33 (227 mg, 1.12 mmol) was added to a

solution of 4-hexylaniline (90%, 220 mg, 1.12 mmol) in 20 mL ace-

tic acid and stirred for 16 h. The solvent was removed in vacuo

and the residue was purified by column chromatography (silica gel,

cyclohexane/dichloromethane, 5:1) to yield 25 (227 mg, 56%) as an

orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.84 (d,

(E)-1-(4-Methylphenyl)-2-{4-[(trimethylsilyl)ethynyl]phenyl}diazene

(23): Following the general method 1, a solution of Oxone^®(24.6 g,

40.0 mmol) in 120 mL water was added to a solution of 4-methyl-

aniline (2.14 g, 20.0 mmol) in 60 mL dichloromethane and the mix-

ture was stirred for 30 min. The crude product was obtained as a

green solid (696 mg, 29%).

3

³J = 8.3 Hz, 2 H, 7-H, 9-H), 7.83 (d, J = 8.3 Hz, 2 H, 13-H, 17-

3

H), 7.59 (d, J = 8.3 Hz, 2 H, 6-H, 10-H), 7.31 (d, J = 8.2 Hz, 2

3

H, 14-H, 16-H), 2.68 (t, J = 7.7 Hz, 2 H, 18-H), 1.65 (quint, J =

7.5 Hz, 2 H, 19-H), 1.39–1.33 (m, 2 H, 20-H), 1.33–1.26 (m, 4 H,

21-H, 22-H), 0.89 (t, J = 7.0 Hz, 3 H, 23-H), 0.27 (s, 9 H, 1-H, 2-

3

H, 3-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 152.14

(C-8), 151.03 (C-12), 147.04 (C-15), 132.85 (C-6, C-10), 129.22 (C-

14, C-16), 125.48 (C-11), 123.05 (C-13, C-17), 122.72 (C-7, C-9),

104.81 (C-5), 96.87 (C-4), 36.01 (C-18), 31.77 (C-21), 31.30 (C-19),

29.02 (C-20), 22.67 (C-22), 14.15 (C-23), 0.00 (C-1, C-2, C-3) ppm.

MS (EI, 70 eV): m/z (%) = 362 (60), 350 (34), 173 (37), 161 (100),

The crude nitroso compound (605 mg, 5.00 mmol) was added to a

solution of 4-[(trimethylsilyl)ethynyl]aniline (19) (945 mg,

5.00 mmol) in 30 mL acetic acid and stirred for 36 h. The resulting

precipitate was separated by filtration and recrystallized from etha-

nol to yield 23 (332 mg, 23 %) as an orange solid. ¹H NMR

105 (9). IR (ATR): ν = 3024 (w), 2958 (m), 2921 (s), 2852 (m), 2150

3

˜

(500.1 MHz, CDCl₃, 25 °C): δ = 7.84 (d, J = 8.5 Hz, 2 H, 7-H, 9-

(s), 1601 (m), 1490 (m), 1447 (m), 1411 (m), 1245 (s), 1221 (s), 1155

(m), 1008 (m), 835 (vs), 753 (s), 645 (s), 571 (s), 506 (s) cm^–1. UV

(toluene): λ_max(lg ε) = 449 (3.26), 355 (4.57) nm. C₂₃H₃₀N₂Si

(362.22): calcd. C 76.19, H 8.34, N 7.73; found C 76.52, H 8.85, N

7.87.

3

H), 7.82 (d, J = 8.6 Hz, 2 H, 13-H, 17-H), 7.59 (d, J = 8.3 Hz, 2

3

H, 6-H, 10-H), 7.31 (d, J = 8.6 Hz, 2 H, 14-H, 16-H), 2.43 (s, 3

H, 18-H), 0.27 (s, 9 H, 1-H, 2-H, 3-H) ppm. ¹³C NMR (125.8 MHz,

CDCl₃, 25 °C): δ = 152.10 (C-8), 150.86 (C-12), 142.00 (C-15),

132.86 (C-6, C-10), 129.87 (C-14, C-16), 125.50 (C-11), 123.05 (C-

13, C-17), 122.73 (C-7, C-9), 104.80 (C-5), 96.89 (C-4), 21.61 (C-

18), 0.00 (C-1, C-2, C-3) ppm. MS (EI, 70 eV): m/z (%) = 292 (100),

(E)-1-(3,5-Dimethylphenyl)-2-{4-[(trimethylsilyl)ethynyl]phenyl}-

diazene (26): 3,5-Dimethylnitrosobenzene^[27](351 mg, 2.60 mmol)

was added to a solution of 4-[(trimethylsilyl)ethynyl]aniline (19)

(491 mg, 2.60 mmol) in 20 mL acetic acid and stirred for 14 h. The

solvent was removed in vacuo and the remaining oil was purified by

column chromatography (silica gel, cyclohexane/dichloromethane,

3:1) to yield 26 (325 mg, 41 %) as an orange solid. ¹H NMR

277 (17), 173 (84), 158 (49), 143 (24), 119 (40). IR (ATR): ν = 3034

˜

(w), 2957 (m), 2900 (w), 2151 (m), 1602 (m), 1491 (m), 1409 (m),

1247 (s), 1225 (m), 1156 (m), 1107 (m), 1011 (m), 839 (vs), 760 (s),

644 (s), 556 (s), 504 (s) cm^–1. UV (toluene): λ_max(lgε) = 447 (3.30),

355 (4.60) nm. C₁₈H₂₀N₂Si (292.14): calcd. C 73.92, H 6.89, N 9.58;

found C 74.10, H 6.98, N 9.79.

3

(500.1 MHz, CDCl₃, 25 °C): δ = 7.84 (d, J = 8.7 Hz, 2 H, 7-H, 9-

3

H), 7.59 (d, J = 8.7 Hz, 2 H, 6-H, 10-H), 7.53 (s, 2 H, 13-H, 17-

(E)-1-[4-(Trifluoromethyl)phenyl]-2-{4[(trimethylsilyl)ethynyl]-

phenyl}diazene (24): Following the general method 1, a solution of

Oxone^®(24.6 g, 40.0 mmol) in 150 mL water was added to a solu-

tion of 4-(trifluoromethyl)aniline (3.22 g, 20.0 mmol) in 40 mL

dichloromethane and the mixture was stirred for 1.5 h. The crude

product (2.41 g) was added to a solution of 4-[(trimethylsilyl)eth-

ynyl]aniline (19) (2.60 g, 13.7 mmol) in 40 mL acetic acid and

stirred for 2 h. The resulting precipitate was separated by filtration

and recrystallized from ethanol to yield 24 (2.24 g, 32% over two

H), 7.13 (s, 1 H, 15-H), 2.41 (s, 6 H, 18-H, 19-H), 0.27 (s, 9 H, 1-

H, 2-H, 3-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ =

152.87 (C-12), 152.02 (C-8), 138.82 (C-14, C-16), 133.01 (C-15),

132.80 (C-6, C-10), 125.55 (C-11), 122.68 (C-7, C-9), 120.75 (C-13,

C-17), 104.70 (C-5), 96.90 (C-4), 21.26 (C-18, C-19), –0.07 (C-1, C-

2, C-3) ppm. MS (EI, 70 eV): m/z (%) = 306 (96), 291 (10), 263 (9),

201 (11), 173 (77), 158 (29), 143 (12), 133 (14), 105 (100). IR (ATR):

ν = 3041 (w), 3009 (w), 2954 (m), 2919 (m), 2858 (w), 2159 (m),

˜

1611 (m), 1492 (m), 1442 (m), 1401 (m), 1246 (s), 1148 (m), 838

(vs), 760 (s), 679 (s), 531 (s) cm^–1. UV (toluene): λ_max(lgε) = 450

(3.19), 346 (4.53) nm. C₁₉H₂₂N₂Si (306.16): calcd. C 74.46, H 7.24,

N 9.14; found C 74.24, H 7.78, N 9.19.

1

steps) as an orange solid. H NMR (500.1 MHz, CDCl₃, 25 °C): δ

3

= 7.99 (d, J = 8.7 Hz, 2 H, 13-H, 17-H), 7.89 (d, J = 8.7 Hz, 2

3

H, 7-H, 9-H), 7.78 (d, J = 8.7 Hz, 2 H, 14-H, 16-H), 7.62 (d, J

= 8.7 Hz, 2 H, 6-H, 10-H), 0.28 (s, 9 H, 1-H, 2-H, 3-H) ppm. ¹³C

NMR (125.8 MHz, CDCl₃, 25 °C): δ = 154.37 (C-12), 151.62 (C-

(E)-1-(3,5-Di-tert-butylphenyl)-2-{4-[(trimethylsilyl)ethynyl]phenyl}-

8), 132.90 (C-6, C-10), 132.30 (C-15), 126.68 (C-11), 126.36 (C-14, diazene (27): Following the general method 1, a solution of Oxone^®

C-16), 124.98 (C-18), 123.11 (C-7, C-9, C-13, C-17), 104.43 (C-5), (19.5 g, 31.7 mmol) in 160 mL water was added to a solution of

97.79 (C-4), –0.09 (C-1, C-2, C-3) ppm. MS (EI, 70 eV): m/z (%) =

4-[(trimethylsilyl)ethynyl]aniline (19) (3.00 g, 15.9 mmol) in 60 mL

Eur. J. Org. Chem. 2010, 5041–5055

www.eurjoc.org

5047

J. Kubitschke, C. Näther, R. Herges

FULL PAPER

dichloromethane and the mixture was stirred for 5 h. The crude

product was purified by column chromatography (silica gel, cyclo-

hexane/dichloromethane, 3:1) to yield a green solid (1.01 g, 31%).

3

= 7.91 (d, J = 9.0 Hz, 2 H, 13-H, 17-H), 7.82 (d, J = 8.6 Hz, 2

3

H, 7-H, 9-H), 7.58 (d, J = 8.6 Hz, 2 H, 6-H, 10-H), 7.01 (d, J =

9.0 Hz, 2 H, 14-H, 16-H), 0.27 (s, 9 H, 1-H, 2-H, 3-H) ppm. ¹³C

NMR (125.8 MHz, CDCl₃, 25 °C): δ = 162.39 (C-15), 152.15 (C-

8), 147.10 (C-12), 132.84 (C-6, C-10), 125.09 (C-11), 124.99 (C-13,

C-17), 122.55 (C-7, C-9), 114.33 (C-14, C-16), 104.87 (C-5), 96.67

(C-4), 54.86 (C-18), 0.00 (C-1, C-2, C-3) ppm. MS (EI, 70 eV): m/z

(%) = 311 (69), 296 (8), 173 (27), 158 (27), 143 (16), 138 (61), 110

The nitroso compound 33 (345 mg, 1.70 mmol) was added to a

solution of 3,5-(di-tert-butyl)aniline (349 mg, 1.70 mmol) in 20 mL

acetic acid and stirred for 16 h. The solvent was removed in vacuo

and the residue was recrystallized from ethanol to yield 27 (406 mg,

1

61%) as an orange solid. H NMR (500.1 MHz, CDCl₃, 25 °C): δ

(100). IR (ATR): ν = 3073 (w), 3054 (w), 2955 (m), 2897 (m), 2250

˜

3

4

= 7.86 (d, J = 8.6 Hz, 2 H, 7-H, 9-H), 7.78 (d, J = 1.8 Hz, 2 H,

(m), 2155 (m), 2071 (m), 1597 (m), 1580 (m), 1491 (m), 1414 (m),

1322 (m), 1298 (m), 1249 (s), 1153 (m), 1142 (m), 1103 (s), 992 (m),

954 (m), 836 (vs), 758 (s), 560 (s) cm^–1. UV (toluene): λ_max(lgε) =

367 (4.61) nm. C₁₈H₁₇D₃N₂OSi (311.15): calcd. C 69.41, H 7.44,

N 8.99; found C 69.69, H 6.65, N 9.11.

3

4

13-H, 17-H), 7.61 (d, J = 8.6 Hz, 2 H, 6-H, 10-H), 7.58 (d, J =

1.8 Hz, 1 H, 15-H), 1.40 (s, 18 H, 19-H, 20-H, 21-H, 23-H, 24-H,

25-H), 0.28 (s, 9 H, 1-H, 2-H, 3-H) ppm. ¹³C NMR (125.8 MHz,

CDCl₃, 25 °C): δ = 152.59 (C-12), 152.16 (C-8), 151.89 (C-14, C-

16), 132.79 (C-6, C-10), 125.65 (C-15), 125.35 (C-11), 122.66 (C-7,

C-9), 117.43 (C-13, C-17), 104.76 (C-5), 96.77 (C-4), 35.13 (C-18,

C-22), 31.46 (C-19, C-20, C-21, C-23, C-24, C-25), –0.04 (C-1, C-

2, C-3) ppm. MS (EI, 70 eV): m/z (%) = 390 (61), 375 (8), 347 (7),

189 (100), 180 (19), 173 (47), 158 (27), 143 (10), 133 (22). IR (ATR):

(E)-1-Phenyl-2-(4-{4-[(trimethylsilyl)ethynyl]phenyl}phenyl)diazene

(40): Nitrosobenzene (282 mg, 2.64 mmol) was added to a solution

of 4-amino-4Ј-[(trimethylsilyl)ethynyl]-1,1Ј-biphenyl (39) (700 mg,

2.64 mmol) in 40 mL acetic acid and stirred for 16 h. The resulting

precipitate was separated by filtration and recrystallized from etha-

nol to yield 40 (567 mg, 61%) as an orange solid. ¹H NMR

ν = 3076 (w), 2961 (m), 2900 (m), 2868 (m), 2157 (m), 1604 (m),

˜

1476 (m), 1458 (m), 1363 (m), 1250 (s), 1221 (m), 1170 (m), 839

(vs), 759 (s), 697 (s), 538 (s) cm^–1. UV (toluene): λ_max(lgε) = 348

(4.52) nm. C₂₅H₃₄N₂Si (390.25): calcd. C 76.87, H 8.77, N 7.17;

found C 76.50, H 9.13, N 7.20.

3

(500.1 MHz, CDCl₃, 25 °C): δ = 8.00 (d, J = 8.6 Hz, 2 H, 14-H,

16-H), 7.94 (d, ³J = 8.2 Hz, 2 H, 19-H, 23-H), 7.74 (d, ³J = 8.6 Hz,

3

2 H, 13-H, 17-H), 7.61 (d, J = 8.5 Hz, 2 H, 7-H, 9-H), 7.56 (d, J

= 8.5 Hz, 2 H, 6-H, 10-H), 7.55–7.46 (m, 3 H, 20-H, 21-H, 22-H),

0.28 (s, 9 H, 1-H, 2-H, 3-H) ppm. ¹³C NMR (150.90 MHz, CDCl₃,

25 °C): δ = 152.73 (C-18), 151.94 (C-15), 142.74 (C-12), 140.08 (C-

8), 132.51 (C-6, C-10), 131.07 (C-21), 129.12 (C-20, C-22), 127.67

(C-13, C-17), 126.92 (C-7, C-9), 123.45 (C-14, C-16), 122.90 (C-19,

C-23), 122.69 (C-11), 104.81 (C-5), 95.44 (C-4), –0.01 (C-1, C-2, C-

(E)-1-(4-Methoxyphenyl)-2-{4-[(trimethylsilyl)ethynyl]phenyl}-

diazene (34): Following the general method 1, a solution of Oxone^®

(19.5 g, 31.7 mmol) in 160 mL water was added to a solution of

4-[(trimethylsilyl)ethynyl]aniline (19) (3.00 g, 15.9 mmol) in 60 mL

dichloromethane and the mixture was stirred for 5 h. The crude

product was purified by column chromatography (silica gel, cyclo-

hexane/dichloromethane, 3:1) yielding a green solid (1.01 g, 31%).

3) ppm. IR (ATR): ν = 3064 (w), 3040 (w), 2956 (m), 2897 (w),

˜

2153 (m), 1594 (m), 1487 (m), 1399 (m), 1245 (s), 1196 (m), 1154

(m), 1071 (m), 1018 (m), 1002 (m), 825 (vs), 757 (s), 687 (s), 542

(s) cm^–1. MS (EI, 70 eV): m/z (%) = 354 (77), 339 (9), 249 (100),

234 (41), 169 (6), 117 (8), 105 (14). UV (toluene): λ_max(lgε) = 355

(4.63) nm. C₂₃H₂₂N₂Si (354.16): calcd. C 77.92, H 6.25, N 7.90;

found C 77.88, H 6.64, N 8.11.

The nitroso compound 33 (860 mg, 4.24 mmol) was added to a

solution of 4-methoxyaniline (522 mg, 4.24 mmol) in 40 mL acetic

acid and stirred for 16 h. The resulting precipitate was separated

by filtration and recrystallized from ethanol to yield 34 (342 mg,

1

26%) as an orange solid. H NMR (500.1 MHz, CDCl₃, 25 °C): δ

3

= 7.92 (d, J = 9.0 Hz, 2 H, 13-H, 17-H), 7.82 (d, J = 8.6 Hz, 2

3

12c-Ethynyl-4,8,12-tri-n-propyl-4,8,12-triazatriangulene (2a): Under

nitrogen atmosphere, sodium (200 mg, 8.70 mmol) was added to

anisole (50 mL) and heated to 110 °C. Acetylene was bubbled

through the mixture for about 2 h until a white suspension oc-

curred. 4,8,12-Tri-n-propyl-4,8,12-triazatriangulenium tetrafluo-

roborate (1a) (300 mg, 0.61 mmol) was added and acetylene was

bubbled through the mixture for 4 h. After 14 h of strirring at

110 °C the mixture was carefully quenched with water. The layers

were separated and the aqueous layer was extracted with diethyl

ether. The combined organic layers were dried with MgSO₄and

filtered. The solvent was removed in vacuo and the obtained resi-

due was recrystallized from diethyl ether to yield 2a (110 mg, 41%)

as a light pink solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ =

H, 7-H, 9-H), 7.58 (d, J = 8.6 Hz, 2 H, 6-H, 10-H), 7.01 (d, J =

9.0 Hz, 2 H, 14-H, 16-H), 3.89 (s, 3 H, 18-H), 0.27 (s, 9 H, 1-H, 2-

H, 3-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 162.33

(C-15), 152.09 (C-8), 147.06 (C-12), 132.78 (C-6, C-10), 125.04 (C-

11), 124.93 (C-13, C-17), 122.50 (C-7, C-9), 114.29 (C-14, C-16),

104.81 (C-5), 96.62 (C-4), 55.61 (C-18), –0.06 (C-1, C-2, C-3) ppm.

MS (EI, 70 eV): m/z (%) = 308 (74), 293 (9), 173 (26), 158 (29), 143

(16), 135 (54), 107 (100). IR (ATR): ν = 3076 (w), 2995 (m), 2955

˜

(m), 2897 (m), 2838 (m), 2156 (m), 1599 (m), 1582 (m), 1497 (m),

1461 (m), 1439 (m), 1414 (m), 1323 (m), 1298 (m), 1244 (s), 1178

(m), 1151 (m), 1140 (m), 1106 (m), 1031 (s), 1010 (m), 835 (vs),

756 (s), 560 (s) cm^–1. UV (toluene): λ_max(lgε) = 365 (4.67) nm.

C₁₈H₂₀N₂OSi (308.13): calcd. C 70.09, H 6.54, N 9.08; found C

70.35, H 6.75, N 9.07.

3

7.19 (t, J = 8.2 Hz, 3 H, 5-H, 11-H, 17-H), 6.52 (d, J = 8.3 Hz,

3

6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H), 3.86 (t, J = 8.0 Hz, 6 H,

(E)-1-[4-([D₃]Methoxy)phenyl]-2-{4-[(trimethylsilyl)ethynyl]phenyl}-

diazene (35): Following the general method 1, a solution of Oxone^®

(19.5 g, 31.7 mmol) in 160 mL water was added to a solution of

4-[(trimethylsilyl)ethynyl]aniline (19) (3.00 g, 15.9 mmol) in 60 mL

dichloromethane and the mixture was stirred for 5 h. The crude

product was purified by column chromatography (silica gel, cyclo-

hexane/dichloromethane, 3:1) to yield a green solid (1.01 g, 31%).

3

20-H, 23-H, 26-H), 2.32 (s, 1 H, 30-H), 1.84 (sext, J = 7.9 Hz, 6

3

H, 21-H, 24-H, 27-H), 1.05 (t, J = 7.4 Hz, 9 H, 22-H, 25-H, 28-

H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 140.35 (C-3,

C-7, C-9, C-13, C-15, C-19), 128.47 (C-5, C-11, C-17), 109.45 (C-

2, C-8, C-14), 104.94 (C-4, C-6, C-10, C-12, C-16, C-18), 87.55 (C-

29), 71.82 (C-30), 48.18 (C-20, C-23, C-26), 27.31 (C-1), 19.01 (C-

21, C-24, C-27), 11.15 (C-22, C-25, C-28) ppm. MS (EI, 70 eV):

m/z (%) = 433 (33), 408 (100), 390 (17), 365 (13), 293 (20), 280 (19).

The nitroso compound 33 (1.00 g, 4.93 mmol) was added to a solu-

tion of 4-([D₃]methoxy)aniline (610 mg, 4.93 mmol) in 40 mL acetic

acid and stirred for 16 h. The solvent was evaporated and the re-

IR (ATR): ν = 3292 (m), 3098 (w), 3028 (w), 2963 (m), 2911 (m),

˜

2874 (m), 1609 (s), 1576 (s), 1478 (s), 1454 (s), 1388 (s), 1362 (s),

1270 (s), 1226 (s), 1164 (m), 1145 (s), 1100 (m), 975 (m), 919 (m),

sulting residue recrystallized from ethanol to yield 35 (690 mg,

45%) as an orange solid. H NMR (500.1 MHz, CDCl₃, 25 °C): δ 888 (m), 764 (s), 709 (s), 656 (s), 637 (m) cm^–1. UV (toluene): λ_max

1

5048

www.eurjoc.org

Eur. J. Org. Chem. 2010, 5041–5055

Triazatriangulenes for Photo-Switchable Self-Assembled Monolayers

(lgε) = 330 (4.03), 296 (4.56) nm. C₃₀H₃₁N₃(433.25): calcd. C

25, C-28) ppm. MS (EI, 70 eV): m/z (%) = 485 (2), 408 (100), 365

83.10, H 7.21, N 9.69; found C 82.68, H 7.39, N 9.60.

(5), 293 (7), 280 (7), 204 (8). IR (ATR): ν = 3098 (w), 3054 (w),

˜

3014 (w), 2960 (m), 2870 (m), 1614 (s), 1579 (s), 1482 (s), 1455 (s),

1395 (s), 1270 (m), 1251 (m), 1230 (s), 1167 (m), 1143 (s), 897 (m),

760 (s), 715 (s), 692 (s), 656 (m), 638 (m) cm^–1. UV (toluene): λ_max

(lgε) = 327 (3.98), 298 (4.39) nm. C₃₄H₃₅N₃(485.28): calcd. C

84.08, H 7.26, N 8.65; found C 84.19, H 7.21, N 8.72.

12c-Ethynyl-4,8,12-tri-n-octyl-4,8,12-triazatriangulene (2b): Under

nitrogen atmosphere, sodium (600 mg, 26.1 mmol) was added to

anisole (150 mL) and heated to 110 °C. Acetylene was bubbled

through the mixture for about 3 h until a white suspension oc-

curred. 4,8,12-Tri-n-octyl-4,8,12-triazatriangulenium tetrafluo-

roborate (1b) (900 mg, 1.28 mmol) was added and acetylene was

bubbled through the mixture for 1.5 h at 110 °C. The mixture was

carefully quenched with water. The layers were separated and the

aqueous layer was extracted with diethyl ether. The combined or-

ganic layers were dried with MgSO₄. After filtration the solvent

was removed in vacuo. The obtained residue was dissolved in

dichloromethane and filtered through a short column of basic alu-

minium oxide. The solvent was evaporated and the resulting residue

recrystallized from diethyl ether to yield 2b (370 mg, 45%) as a

12c-Phenyl-4,8,12-tri-n-octyl-4,8,12-triazatriangulene (3b): Under

nitrogen atmosphere, n-Butyllithium (1.72 mmol, 0.69 mL of a

2.5  solution in hexane) was added to a solution of bromobenzene

(270 mg, 1.72 mmol) in 30 mL THF at –78 °C and the mixture was

stirred for 1 h. 4,8,12-Tri-n-octyl-4,8,12-triazatriangulenium tetra-

fluoroborate (1b) (600 mg, 0.86 mmol) was added and the mixture

was sonicated for 4 h at 0 °C using a Branson Sonifier W-450. The

mixture was quenched with water, the layers were separated and

the aqueous layer was extracted with diethyl ether. The combined

organic layers were dried with MgSO₄and the solvents were re-

light pink solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.19 (t,

³J = 8.2 Hz, 3 H, 5-H, 11-H, 17-H), 6.53 (d, J = 8.3 Hz, 6 H, 4- moved in vacuo. The obtained residue was dissolved in dichloro-

H, 6-H, 10-H, 12-H, 16-H, 18-H), 3.90 (t, J = 7.9 Hz, 6 H, 20-H, methane and filtered through a short column of basic aluminium

3

28-H, 36-H), 2.31 (s, 1 H, 45-H), 1.81 (quint, J = 7.4 Hz, 6 H, 21-

oxide. The solvent was evaporated and the resulting residue recrys-

tallized from diethyl ether to yield 3b (170 mg, 28%) as a colorless

solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.16 (t, ³J =

3

H, 29-H, 37-H), 1.46 (quint, J = 7.3 Hz, 6 H, 22-H, 30-H, 38-H),

1.38 (quint, ³J = 7.5 Hz, 6 H, 23-H, 31-H, 39-H), 1.35–1.25 (m, 18

H, 24-H, 25-H, 26-H, 32-H, 33-H, 34-H, 40-H, 41-H, 42-H), 0.89 8.2 Hz, 3 H, 5-H, 11-H, 17-H), 6.99–6.89 (m, 3 H, 46-H, 47-H, 48-

3

(t, ³J = 6.8 Hz, 9 H, 27-H, 35-H, 43-H) ppm. ¹³C NMR

H), 6.87–6.83 (m, 2 H, 45-H, 49-H), 6.52 (d, J = 8.3 Hz, 6 H, 4-

3

(125.8 MHz, CDCl₃, 25 °C): δ = 140.26 (C-3, C-7, C-9, C-13, C- H, 6-H, 10-H, 12-H, 16-H, 18-H), 3.82 (t, J = 7.9 Hz, 6 H, 20-H,

15, C-19), 128.48 (C-5, C-11, C-17), 109.24 (C-2, C-8, C-14), 104.84

(C-4, C-6, C-10, C-12, C-16, C-18), 87.50 (C-44), 71.83 (C-45),

28-H, 36-H), 1.78 (quint, ³J = 7.3 Hz, 6 H, 21-H, 29-H, 37-H),

1.39–1.24 (m, 30 H, 22-H, 23-H, 24-H, 25-H, 26-H, 30-H, 31-H,

46.57 (C-20, C-28, C-36), 31.85 (C-25, C-33, C-41), 29.39 (C-23, C- 32-H, 33-H, 34-H, 38-H, 39-H, 40-H, 41-H, 42-H), 0.89 (t, ³J =

31, C-39), 29.37 (C-24, C-32, C-40), 27.26 (C-1), 27.02 (C-22, C- 6.9 Hz, 9 H, 27-H, 35-H, 43-H) ppm. ¹³C NMR (125.8 MHz,

30, C-38), 25.60 (C-21, C-29, C-37), 22.68 (C-26, C-34, C-42), 14.13

CDCl₃, 25 °C): δ = 149.01 (C-44), 140.81 (C-3, C-7, C-9, C-13, C-

(C-27, C-35, C-43) ppm. MS (EI, 70 eV): m/z (%) = 643 (100), 618 15, C-19), 127.97 (C-46, C-48), 127.76 (C-5, C-11, C-17), 125.93

(91), 530 (24), 505 (25), 393 (11), 321 (20), 294 (22), 280 (15), 97

(15). IR (ATR): ν = 3263 (m), 3096 (w), 3028 (w), 2950 (m), 2921

(C-47), 125.46 (C-45, C-49), 112.91 (C-2, C-8, C-14), 104.60 (C-4,

C-6, C-10, C-12, C-16, C-18), 46.59 (C-20, C-28, C-36), 36.78 (C-

˜

(s), 2851 (m), 1614 (s), 1578 (vs), 1482 (s), 1457 (vs), 1397 (vs), 1), 31.88 (C-25, C-33, C-41), 29.39 (C-23, C-31, C-39), 29.36 (C-

1372 (m), 1272 (m), 1246 (s), 1169 (s), 1148 (m), 974 (m), 910 (m), 24, C-32, C-40), 27.07 (C-22, C-30, C-38), 25.73 (C-21, C-29, C-

766 (s), 748 (m), 715 (vs), 666 (m), 649 (m) cm^–1. UV (toluene):

λ_max(lgε) = 332 (4.06), 296 (4.56) nm. C₄₅H₆₁N₃(643.49): calcd.

C 83.93, H 9.55, N 6.53; found C 84.34, H 9.82, N 6.42.

37), 22.70 (C-26, C-34, C-42), 14.15 (C-27, C-35, C-43) ppm. MS

(EI, 70 eV): m/z (%) = 695 (1), 618 (100), 505 (5), 393 (1), 348 (3),

309 (10), 280 (2). IR (ATR): ν = 3053 (w), 3024 (w), 2951 (m),

˜

2921 (s), 2869 (m), 2851 (m), 1613 (s), 1580 (vs), 1483 (s), 1456

(vs), 1397 (vs), 1374 (s), 1268 (s), 1247 (s), 1166 (s), 1147 (m), 896

(m), 762 (vs), 716 (vs), 694 (s), 657 (m), 640 (m) cm^–1. UV (toluene):

λ_max(lgε) = 328 (4.04), 294 (4.62) nm. C₄₉H₆₅N₃(695.52): calcd.

C 84.55, H 9.41, N 6.04; found C 84.68, H 9.69, N 6.09.

12c-Phenyl-4,8,12-tri-n-propyl-4,8,12-triazatriangulene (3a): Under

nitrogen atmosphere, n-Butyllithium (1.47 mmol, 0.59 mL of a

2.5  solution in hexane) was added to a solution of bromobenzene

(231 mg, 1.47 mmol) in 30 mL THF at –78 °C and the mixture was

stirred for 1 h. 4,8,12-Tri-n-propyl-4,8,12-triazatriangulenium tetra-

fluoroborate (1a) (300 mg, 0.61 mmol) was added and the mixture

was sonicated for 1.5 h at 0 °C using a Branson Sonifier W-450.

The mixture was quenched with water, the layers were separated

and the aqueous layer was extracted with diethyl ether. The com-

bined organic layers were dried with MgSO₄and the solvents were

removed in vacuo. The obtained residue was dissolved in dichloro-

methane and filtered through a short column of basic aluminium

oxide. The solvent was evaporated and the resulting residue recrys-

tallized from diethyl ether to yield 3a (140 mg, 47%) as colorless

crystals. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.16 (t, ³J =

8.2 Hz, 3 H, 5-H, 11-H, 17-H), 7.00–6.91 (m, 3 H, 31-H, 32-H, 33-

12c-Phenylethynyl-4,8,12-tri-n-propyl-4,8,12-triazatriangulene (4a):

Under nitrogen atmosphere, n-butyllithium (1.22 mmol, 0.48 mL of

a 2.5  solution in hexane) was added to a solution of phenylacetyl-

ene (124 mg, 1.22 mmol) in 50 mL THF and the mixture was

stirred for 3 h at 0 °C. At room temperature, 4,8,12-tri-n-propyl-

4,8,12-triazatriangulenium tetra-fluoroborate (1a) (250 mg,

0.51 mmol) was suspended in the mixture and stirred for 3 d. The

mixture was quenched with water, the layers were separated and

the aqueous layer was extracted with diethyl ether. The combined

organic layers were dried with MgSO₄and the solvents were re-

moved in vacuo. Recrystallization of the resulting residue from di-

3

4

3

H), 6.86 (dd, J = 8.4, J = 1.4 Hz, 2 H, 30-H, 34-H), 6.52 (d, J

ethyl ether yielded 4a (168 mg, 65%) as light pink crystals. ¹H

3

= 8.2 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H), 3.78 (t, ³J = NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.17 (t, J = 8.2 Hz, 3 H,

3

8.1 Hz, 6 H, 20-H, 23-H, 26-H), 1.81 (sext, J = 7.7 Hz, 6 H, 21- 5-H, 11-H, 17-H), 7.08–7.10 (m, 5 H, 32-H, 33-H, 34-H, 35-H, 36-

3

H, 24-H, 27-H), 0.96 (t, J = 7.4 Hz, 9 H, 22-H, 25-H, 28-H) ppm.

H), 6.53 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H),

¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 148.99 (C-29), 140.86 3.88 (t, ³J = 7.8 Hz, 6 H, 20-H, 23-H, 26-H), 1.86 (sext, ³J = 7.7 Hz,

(C-3, C-7, C-9, C-13, C-15, C-19), 127.98 (C-31, C-33), 127.79 (C- 6 H, 21-H, 24-H, 27-H), 1.04 (t, ³J = 7.4 Hz, 9 H, 22-H, 25-H, 28-

5, C-11, C-17), 125.91 (C-32), 125.50 (C-30, C-34), 112.95 (C-2, C-

8, C-14), 104.67 (C-4, C-6, C-10, C-12, C-16, C-18), 48.28 (C-20, C-7, C-9, C-13, C-15, C-19), 131.54 (C-32, C-36), 128.12 (C-5, C-

C-23, C-26), 36.81 (C-1), 19.04 (C-21, C-24, C-27), 11.10 (C-22, C- 11, C-17), 127.69 (C-33, C-35), 127.22 (C-34), 124.08 (C-31), 110.44

H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 140.58 (C-3,

Eur. J. Org. Chem. 2010, 5041–5055

www.eurjoc.org

5049

J. Kubitschke, C. Näther, R. Herges

(C-2, C-8, C-14), 104.99 (C-4, C-6, C-10, C-12, C-16, C-18), 93.53 131.38 (C-48, C-50), 128.97 (C-46), 128.44 (C-5, C-11, C-17),

FULL PAPER

(C-29), 83.56 (C-30), 48.09 (C-20, C-23, C-26), 27.99 (C-1), 19.24

(C-21, C-24, C-27), 11.19 (C-22, C-25, C-28) ppm. MS (EI, 70 eV):

118.67 (C-52), 110.46 (C-49), 109.43 (C-2, C-8, C-14), 104.97 (C-4,

C-6, C-10, C-12, C-16, C-18), 98.20 (C-44), 82.37 (C-45), 46.47 (C-

m/z (%) = 509 (66), 466 (29), 408 (100), 365 (32), 293 (15), 280 (13), 20, C-28, C-36), 31.83 (C-25, C-33, C-41), 29.38 (C-23, C-31, C-

102 (57). IR (ATR): ν = 3028 (w), 2953 (m), 2868 (m), 2186 (w),

39), 29.32 (C-24, C-32, C-40), 28.36 (C-1), 26.98 (C-22, C-30, C-

38), 25.77 (C-21, C-29, C-37), 22.65 (C-26, C-34, C-42), 14.11 (C-

˜

1900 (w), 1612 (s), 1576 (s), 1482 (s), 1453 (s), 1394 (s), 1229 (s),

1143 (s), 1115 (m), 917 (m), 891 (m), 751 (s), 687 (s), 657 (m) cm^–1. 27, C-35, C-43) ppm. MS (MALDI-TOF, Cl-CCA): m/z = 744

UV (toluene): λ_max(lgε) = 335 (4.05) nm. C₃₆H₃₅N₃(509.28): calcd.

[M]⁺. IR (ATR): ν = 3095 (w), 3025 (w), 2952 (m), 2922 (s), 2851

˜

C 84.83, H 6.92, N 8.24; found C 84.54, H 7.12, N 8.19.

(m), 2226 (m), 1615 (s), 1579 (vs), 1483 (s), 1456 (vs), 1396 (vs),

1374 (s), 1267 (s), 1246 (s), 1166 (s), 1147 (m), 983 (m), 840 (m),

767 (s), 721 (s), 657 (m), 554 (m) cm^–1. C₅₂H₆₄N₄(744.51): calcd.

C 83.82, H 8.66, N 7.52; found C 83.54, H 8.84, N 7.42.

12c-Phenylethynyl-4,8,12-tri-n-octyl-4,8,12-triazatriangulene (4b):

Under nitrogen atmosphere, n-Butyllithium (1.25 mmol, 0.50 mL

of a 2.5  solution in hexane) was added to a solution of phenyl-

acetylene (132 mg, 1.29 mmol) in 10 mL THF at 0 °C. After 30 min (E)-12c-[4-(Phenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-propyl-

4,8,12-tri-n-octyl-4,8,12-triazatriangulenium tetrafluoroborate 1b

(300 mg, 0.43 mmol) was added and the mixture was sonicated for

4,8,12-triazatriangulene (6a): Following the general method 2,

KOH (300 mg, 5.36 mmol) was added to a solution of 20 (169 mg,

3 h at 0 °C using a Branson Sonifier W-450. The mixture was 0.61 mmol) in 40 mL THF. After 20 min of sonication, 1a (300 mg,

quenched with water, the layers were separated and the aqueous 0.61 mmol) was added and the mixture was sonicated for 5 h. After

layer was extracted with diethyl ether. The combined organic layers recrystallization from diethyl ether, 6a (246 mg, 66%) was obtained

were dried with MgSO₄and the solvents were removed in vacuo.

The obtained residue was dissolved in dichloromethane and filtered

through a short column of basic aluminium oxide. The solvent was

evaporated and the resulting residue recrystallized from diethyl

ether to yield 4b (241 mg, 79%) as a light pink solid. ¹H NMR

(500.1 MHz, CDCl₃, 25 °C): δ = 7.18 (t, ³J = 8.2 Hz, 3 H, 5-H, 11-

as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.84

3

(d, J = 8.2 Hz, 2 H, 38-H, 42-H), 7.68 (d, J = 8.7 Hz, 2 H, 33-

H, 35-H), 7.49–7.41 (m, 3 H, 39-H, 40-H, 41-H), 7.23 (d, ³J =

3

8.8 Hz, 2 H, 32-H, 36-H), 7.19 (t, J = 8.2 Hz, 3 H, 5-H, 11-H, 17-

3

H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H),

3.90 (t, ³J = 7.8 Hz, 6 H, 20-H, 23-H, 26-H), 1.87 (sext, ³J = 7.7 Hz,

H, 17-H), 7.12–7.07 (m, 5 H, 47-H, 48-H, 49-H, 50-H, 51-H), 6.53 6 H, 21-H, 24-H, 27-H), 1.05 (t, ³J = 7.4 Hz, 9 H, 22-H, 25-H, 28-

3

(d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H), 3.91 (t, H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 152.68 (C-37),

³J = 7.8 Hz, 6 H, 20-H, 28-H, 36-H), 1.82 (quint, ³J = 7.3 Hz, 6

151.18 (C-34), 140.60 (C-3, C-7, C-9, C-13, C-15, C-19), 132.32 (C-

3

H, 21-H, 29-H, 37-H), 1.45 (quint, J = 7.2 Hz, 6 H, 22-H, 30-H, 32, C-36), 130.98 (C-40), 129.05 (C-39, C-41), 128.27 (C-5, C-11,

38-H), 1.36 (quint, ³J = 7.1 Hz, 6 H, 23-H, 31-H, 39-H), 1.33–1.22

C-17), 126.94 (C-31), 122.82 (C-38, C-42), 122.37 (C-33, C-35),

(m, 18 H, 24-H, 25-H, 26-H, 32-H, 33-H, 34-H, 40-H, 41-H, 42- 110.17 (C-2, C-8, C-14), 105.07 (C-4, C-6, C-10, C-12, C-16, C-18),

3

H), 0.88 (t, J = 6.8 Hz, 9 H, 27-H, 35-H, 43-H) ppm. ¹³C NMR

96.28 (C-29), 83.50 (C-30), 48.09 (C-20, C-23, C-26), 28.28 (C-1),

19.24 (C-21, C-24, C-27), 11.18 (C-22, C-25, C-28) ppm. MS (EI,

(125.8 MHz, CDCl₃, 25 °C): δ = 140.48 (C-19), C-3, C-7, C-9, C-

13, C-15, 131.60 (C-47, C-51), 128.13 (C-5, C-11, C-17), 127.64 (C- 70 eV): m/z (%) = 613 (10), 408 (63), 365 (100), 323 (19), 293 (23),

48, C-50), 127.23 (C-49), 124.01 (C-46), 110.21 (C-2, C-8, C-14), 280 (20), 206 (66), 129 (24), 105 (20), 101 (78). IR (ATR): ν = 3014

˜

104.87 (C-4, C-6, C-10, C-12, C-16, C-18), 93.42 (C-44), 83.60 (C- (w), 2956 (m), 2922 (m), 2867 (m), 1608 (s), 1577 (s), 1480 (s), 1453

45), 46.53 (C-20, C-28, C-36), 31.87 (C-25, C-33, C-41), 29.42 (C- (s), 1377 (s), 1227 (s), 1167 (s), 1132 (s), 987 (m), 918 (m), 841 (m),

23, C-31, C-39), 29.34 (C-24, C-32, C-40), 27.91 (C-1), 27.03 (C- 748 (s), 698 (s), 682 (s), 550 (m) cm^–1. UV (toluene): λ_max(lgε) =

22, C-30, C-38), 25.86 (C-21, C-29, C-37), 22.66 (C-26, C-34, C- 356 (4.54), 336 (4.59) nm. C₄₂H₃₉N₅(613.32): calcd. C 82.19, H

42), 14.13 (C-27, C-35, C-43) ppm. MS (EI, 70 eV): m/z (%) = 719

6.40, N 11.41; found C 82.11, H 6.75, N 11.17.

(58), 618 (100), 606 (13), 505 (78), 359 (14), 309 (12), 293 (10), 280

(E)-12c-[4-(Phenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-octyl-4,8,12-

triazatriangulene (6b): Following the general method 2, KOH

(300 mg, 5.36 mmol) was added to a solution of 20 (167 mg,

0.60 mmol) in 30 mL THF. After 20 min of sonication, 1b (423 mg,

0.60 mmol) was added and the mixture was sonicated for 4 h. After

recrystallization from diethyl ether, 6b (344 mg, 70%) was obtained

as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.84

(9), 202 (12), 102 (77). IR (ATR): ν = 3078 (w), 3027 (w), 2953

˜

(m), 2921 (s), 2851 (m), 1615 (s), 1579 (s), 1484 (s), 1457 (s), 1395

(s), 1373 (m), 1266 (m), 1246 (s), 1166 (s), 1148 (m), 912 (m), 753

(vs), 722 (m), 701 (s), 690 (s), 658 (m) cm^–1. UV (toluene): λ_max

(lgε) = 335 (4.07) nm. C₅₁H₆₅N₃(719.52): calcd. C 85.07, H 9.10,

N 5.84; found C 85.23, H 9.41, N 5.93.

3

12c-(4-Cyanophenyl)ethynyl-4,8,12-tri-n-octyl-4,8,12-triazatri-

angulene (5b): Following the general method 2, KOH (300 mg,

5.36 mmol) was added to a solution of 4-[(trimethylsilyl)ethynyl]-

benzonitrile^[26](86 mg, 0.43 mmol) in 40 mL THF. After 20 min of

sonication, 1b (300 mg, 0.43 mmol) was added and the mixture was

sonicated for 5 h. After recrystallization from diethyl ether, 5b

(129 mg, 40 %) was obtained as a light pink solid. ¹H NMR

(d, J = 8.4 Hz, 2 H, 53-H, 57-H), 7.67 (d, J = 8.4 Hz, 2 H, 48-

H, 50-H), 7.49–7.40 (m, 3 H, 54-H, 55-H, 56-H), 7.23 (d, ³J =

3

8.4 Hz, 2 H, 47-H, 51-H), 7.20 (t, J = 8.3 Hz, 3 H, 5-H, 11-H, 17-

3

H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H),

3.93 (t, ³J = 7.7 Hz, 6 H, 20-H, 28-H, 36-H), 1.83 (quint, ³J =

3

7.2 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint, J = 7.4 Hz, 6 H, 22-

3

H, 30-H, 38-H), 1.37 (quint, J = 7.0 Hz, 6 H, 23-H, 31-H, 39-H),

3

(500.1 MHz, CDCl₃, 25 °C): δ = 7.37 (d, J = 8.3 Hz, 2 H, 48-H,

1.33–1.22 (m, 18 H, 24-H, 25-H, 26-H, 32-H, 33-H, 34-H, 40-H,

3

50-H), 7.20 (t, J = 8.2 Hz, 3 H, 5-H, 11-H, 17-H), 7.16 (d, J = 41-H, 42-H), 0.87 (t, ³J = 6.8 Hz, 9 H, 27-H, 35-H, 43-H) ppm.

8.3 Hz, 2 H, 47-H, 51-H), 6.54 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10- ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 152.66 (C-52), 151.14

H, 12-H, 16-H, 18-H), 3.91 (t, J = 7.9 Hz, 6 H, 20-H, 28-H, 36-

H), 1.81 (quint, J = 7.5 Hz, 6 H, 21-H, 29-H, 37-H), 1.44 (quint, 51), 130.99 (C-55), 129.06 (C-54, C-56), 128.29 (C-5, C-11, C-17),

³J = 7.7 Hz, 6 H, 22-H, 30-H, 38-H), 1.36 (quint, ³J = 7.3 Hz, 6

126.95 (C-46), 122.82 (C-53, C-57), 122.36 (C-48, C-50), 109.97 (C-

H, 23-H, 31-H, 39-H), 1.32–1.20 (m, 18 H, 24-H, 25-H, 26-H, 32- 2, C-8, C-14), 104.97 (C-4, C-6, C-10, C-12, C-16, C-18), 96.24 (C-

3

(C-49), 140.53 (C-3, C-7, C-9, C-13, C-15, C-19), 132.41 (C-47, C-

3

H, 33-H, 34-H, 40-H, 41-H, 42-H), 0.88 (t, J = 6.9 Hz, 9 H, 27-

44), 83.54 (C-45), 46.53 (C-20, C-28, C-36), 31.88 (C-25, C-33, C-

H, 35-H, 43-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 41), 29.44 (C-23, C-31, C-39), 29.36 (C-24, C-32, C-40), 28.24 (C-

140.47 (C-3, C-7, C-9, C-13, C-15, C-19), 132.13 (C-47, C-51), 1), 27.04 (C-22, C-30, C-38), 25.87 (C-21, C-29, C-37), 22.68 (C-

5050

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Eur. J. Org. Chem. 2010, 5041–5055

Triazatriangulenes for Photo-Switchable Self-Assembled Monolayers

26, C-34, C-42), 14.15 (C-27, C-35, C-43) ppm. MS (EI, 70 eV): (s), 1372 (s), 1266 (m), 1243 (s), 1166 (s), 1005 (m), 844 (m), 792

m/z (%) = 823 (4), 618 (10), 505 (9), 206 (100), 176 (22), 151 (18),

129 (67), 105 (25), 101 (97). IR (ATR): ν = 3102 (w), 3028 (w), (4.60), 337 (4.56), 296 (4.74) nm. C₅₇H₆₈IN₅(949.45): calcd. C

(m), 751 (s), 705 (s), 551 (m) cm^–1. UV (toluene): λ_max(lgε) = 365

˜

2951 (m), 2924 (s), 2852 (m), 1613 (s), 1577 (s), 1480 (s), 1455 (s),

1388 (s), 1368 (s), 1242 (s), 1224 (s), 1168 (s), 1151 (s), 847 (s), 767

(m), 752 (s), 724 (m), 701 (m), 685 (s), 629 (m), 555 (m) cm^–1. UV

(toluene): λ_max(lg ε) = 352 (4.51), 336 (4.55), 297 (4.68) nm.

C₅₇H₆₉N₅(823.56): calcd. C 83.06, H 8.44, N 8.50; found C 83.37,

H 8.78, N 8.59.

72.06, H 7.21, N 7.37; found C 71.61, H 7.58, N 7.64.

(E)-12c-[4-(4-Cyanophenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-

propyl-4,8,12-triazatriangulene (8a): Following the general method

2, KOH (300 mg, 5.36 mmol) was added to a solution of 22

(185 mg, 0.61 mmol) in 30 mL THF. After 20 min of sonication, 1a

(300 mg, 0.61 mmol) was added and the mixture was sonicated for

3 h. After two recrystallizations from ethanol, 8a (146 mg, 38%)

was obtained as an red solid. ¹H NMR (500.1 MHz, CDCl₃,

(E)-12c-[4-(4-Iodophenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-propyl-

4,8,12-triazatriangulene (7a): Following the general method 2,

KOH (300 mg, 5.36 mmol) was added to a solution of 21 (246 mg,

0.61 mmol) in 40 mL THF. After 20 min of sonication, 1a (300 mg,

0.61 mmol) was added and the mixture was sonicated for 5 h. After

recrystallization from diethyl ether, 7a (232 mg, 51%) was obtained

as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.82

3

25 °C): δ = 7.90 (d, J = 8.7 Hz, 2 H, 39-H, 41-H), 7.75 (d, ³J =

3

8.7 Hz, 2 H, 38-H, 42-H), 7.70 (d, J = 8.7 Hz, 2 H, 33-H, 35-H),

3

7.25 (d, J = 8.7 Hz, 2 H, 32-H, 36-H), 7.20 (t, J = 8.3 Hz, 3 H,

3

5-H, 11-H, 17-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-

H, 16-H, 18-H), 3.90 (t, ³J = 7.8 Hz, 6 H, 20-H, 23-H, 26-H), 1.87

3

(d, J = 8.8 Hz, 2 H, 39-H, 41-H), 7.67 (d, J = 8.8 Hz, 2 H, 33-

3

(sext, J = 7.7 Hz, 6 H, 21-H, 24-H, 27-H), 1.05 (t, J = 7.4 Hz, 9

H, 22-H, 25-H, 28-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C):

δ = 154.47 (C-37), 150.82 (C-34), 140.55 (C-3, C-7, C-9, C-13, C-

15, C-19), 133.16 (C-39, C-41), 132.47 (C-32, C-36), 128.34 (C-5,

C-11, C-17), 126.33 (C-31), 123.29 (C-38, C-42), 122.84 (C-33, C-

35), 118.40 (C-43), 113.85 (C-40), 109.88 (C-2, C-8, C-14), 105.05

(C-4, C-6, C-10, C-12, C-16, C-18), 97.26 (C-29), 83.39 (C-30),

48.06 (C-20, C-23, C-26), 28.40 (C-1), 19.14 (C-21, C-24, C-27),

11.19 (C-22, C-25, C-28) ppm. MS (EI, 70 eV): m/z (%) = 638 (3),

596 (2), 408 (21), 365 (22), 231 (49),129 (24), 118 (41), 101 (100).

H, 35-H), 7.57 (d, ³J = 8.8 Hz, 2 H, 38-H, 42-H), 7.23 (d, ³J =

8.8 Hz, 2 H, 32-H, 36-H), 7.19 (t, J = 8.2 Hz, 3 H, 5-H, 11-H, 17-

H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H),

3

3.90 (t, ³J = 7.8 Hz, 6 H, 20-H, 23-H, 26-H), 1.87 (sext, ³J = 7.7 Hz,

6 H, 21-H, 24-H, 27-H), 1.05 (t, ³J = 7.4 Hz, 9 H, 22-H, 25-H, 28-

H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 151.99 (C-37),

151.01 (C-34), 140.62 (C-3, C-7, C-9, C-13, C-15, C-19), 138.35 (C-

39, C-41), 132.40 (C-32, C-36), 128.30 (C-5, C-11, C-17), 127.38

(C-31), 124.43 (C-38, C-42), 122.50 (C-33, C-35), 110.14 (C-2, C-

8, C-14), 105.09 (C-4, C-6, C-10, C-12, C-16, C-18), 101.10 (C-40),

96.63 (C-29), 83.49 (C-30), 48.10 (C-20, C-23, C-26), 28.90 (C-1),

19.25 (C-21, C-24, C-27), 11.19 (C-22, C-25, C-28) ppm. MS (EI,

70 eV): m/z (%) = 739 (8), 696 (5), 408 (46), 365 (69), 332 (82), 323

(14), 293 (17), 280 (15), 231 (23), 203 (48), 129 (44), 101 (100). IR

IR (ATR): ν = 3101 (w), 3024 (w), 2960 (m), 2930 (m), 2873 (m),

˜

2229 (m), 1613 (s), 1578 (s), 1482 (s), 1455 (s), 1393 (s), 1271 (m),

1230 (s), 1173 (m), 1142 (s), 1100 (m), 918 (m), 858 (s), 756 (s), 726

(m), 687 (m), 566 (s) cm^–1. UV (toluene): λ_max(lgε) = 368 (4.21),

336 (4.19), 296 (4.39) nm. C₄₃H₃₈N₆(638.32): calcd. C 80.85, H

6.00, N 13.16; found C 80.39, H 6.36, N 13.15.

(ATR): ν = 3018 (w), 2955 (m), 2864 (m), 1607 (s), 1577 (s), 1479

˜

(s), 1451 (s), 1376 (s), 1227 (s), 1166 (s), 1131 (s), 1003 (m), 918

(m), 840 (s), 750 (s), 700 (s), 654 (m), 547 (m) cm^–1. UV (toluene):

λ_max(lgε) = 364 (4.50), 339 (4.45) nm. C₄₂H₃₈IN₅(739.22): calcd.

C 68.20, H 5.18, N 9.47; found C 68.10, H 5.10, N 9.37.

(E)-12c-[4-(4-Cyanophenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-octyl-

4,8,12-triazatriangulene (8b): Following the general method 2,

KOH (300 mg, 5.36 mmol) was added to a solution of 22 (130 mg,

0.43 mmol) in 30 mL THF. After 20 min of sonication, 1b (300 mg,

0.43 mmol) was added and the mixture was sonicated for 4 h. After

(E)-12c-[4-(4-Iodophenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-octyl-

4,8,12-triazatriangulene (7b): Following the general method 2,

KOH (300 mg, 5.36 mmol) was added to a solution of 21 (242 mg, recrystallization from ethanol/dichloromethane (1:1), 8b (151 mg,

1

0.60 mmol) in 30 mL THF. After 20 min of sonication, 1b (423 mg,

0.60 mmol) was added and the mixture was sonicated for 4 h. After

recrystallization from diethyl ether, 7b (377 mg, 66%) was obtained

as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.81

41%) was obtained as a red solid. H NMR (500.1 MHz, CDCl₃,

25 °C): δ = 7.90 (d, J = 8.7 Hz, 2 H, 53-H, 57-H), 7.76 (d, ³J =

3

8.7 Hz, 2 H, 54-H, 56-H), 7.69 (d, J = 8.7 Hz, 2 H, 48-H, 50-H),

3

7.25 (d, J = 8.0 Hz, 2 H, 47-H, 51-H), 7.20 (t, J = 8.2 Hz, 3 H,

3

(d, J = 8.7 Hz, 2 H, 54-H, 56-H), 7.66 (d, J = 8.6 Hz, 2 H, 48- 5-H, 11-H, 17-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-

H, 50-H), 7.57 (d, ³J = 8.7 Hz, 2 H, 53-H, 57-H), 7.22 (d, ³J =

H, 16-H, 18-H), 3.93 (t, ³J = 7.8 Hz, 6 H, 20-H, 28-H, 36-H), 1.83

3

8.6 Hz, 2 H, 47-H, 51-H), 7.20 (t, J = 8.2 Hz, 3 H, 5-H, 11-H, 17-

(quint, ³J = 7.5 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint, ³J =

3

H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H), 7.7 Hz, 6 H, 22-H, 30-H, 38-H), 1.36 (quint, J = 7.4 Hz, 6 H, 23-

3.93 (t, ³J = 7.9 Hz, 6 H, 20-H, 28-H, 36-H), 1.83 (quint, ³J =

H, 31-H, 39-H), 1.32–1.21 (m, 18 H, 24-H, 25-H, 26-H, 32-H, 33-

3

7.5 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint, J = 7.5 Hz, 6 H, 22-

H, 34-H, 40-H, 41-H, 42-H), 0.87 (t, J = 6.9 Hz, 9 H, 27-H, 35-

3

H, 30-H, 38-H), 1.36 (quint, J = 7.1 Hz, 6 H, 23-H, 31-H, 39-H),

H, 43-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 154.50

1.31–1.21 (m, 18 H, 24-H, 25-H, 26-H, 32-H, 33-H, 34-H, 40-H,

(C-52), 150.83 (C-49), 140.52 (C-3, C-7, C-9, C-13, C-15, C-19),

41-H, 42-H), 0.87 (t, ³J = 6.9 Hz, 9 H, 27-H, 35-H, 43-H) ppm. 133.17 (C-54, C-56), 132.53 (C-47, C-51), 128.34 (C-5, C-11, C-17),

¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 151.94 (C-52), 150.93 128.30 (C-46), 123.28 (C-53, C-57), 122.81 (C-48, C-50), 118.48 (C-

(C-49), 140.51 (C-3, C-7, C-9, C-13, C-15, C-19), 138.32 (C-54, C- 58), 113.86 (C-55), 109.82 (C-2, C-8, C-14), 104.98 (C-4, C-6, C-

56), 132.45 (C-47, C-51), 128.30 (C-5, C-11, C-17), 127.34 (C-46),

10, C-12, C-16, C-18), 97.26 (C-44), 83.41 (C-45), 46.50 (C-20, C-

124.41 (C-53, C-57), 122.46 (C-48, C-50), 109.90 (C-2, C-8, C-14), 28, C-36), 31.86 (C-25, C-33, C-41), 29.41 (C-23, C-31, C-39), 29.33

104.96 (C-4, C-6, C-10, C-12, C-16, C-18), 97.65 (C-55), 96.55 (C- (C-24, C-32, C-40), 28.34 (C-1), 27.02 (C-22, C-30, C-38), 25.86

44), 83.51 (C-45), 46.52 (C-20, C-28, C-36), 31.87 (C-25, C-33, C- (C-21, C-29, C-37), 22.65 (C-26, C-34, C-42), 14.11 (C-27, C-35,

41), 29.43 (C-23, C-31, C-39), 29.35 (C-24, C-32, C-40), 28.26 (C- C-43) ppm. MS (MALDI-TOF, Cl-CCA): m/z = 848 [M]⁺. IR

1), 27.03 (C-22, C-30, C-38), 25.85 (C-21, C-29, C-37), 22.67 (C- (ATR): ν = 3097 (w), 3028 (w), 2953 (m), 2922 (s), 2852 (m), 2227

˜

26, C-34, C-42), 14.13 (C-27, C-35, C-43) ppm. MS (MALDI-TOF, (m), 1614 (s), 1579 (s), 1482 (s), 1455 (s), 1393 (s), 1373 (s), 1266

Cl-CCA): m/z = 949 [M]⁺. IR (ATR): ν = 3098 (w), 3025 (w), 2951 (m), 1242 (s), 1167 (s), 1141 (m), 851 (s), 758 (s), 726 (s), 688 (s),

˜

(m), 2922 (s), 2852 (m), 1613 (s), 1579 (s), 1482 (s), 1456 (s), 1392

564 (s) cm^–1. UV (toluene): λ_max(lgε) = 368 (4.56), 338 (4.52), 296

Eur. J. Org. Chem. 2010, 5041–5055

www.eurjoc.org

5051

J. Kubitschke, C. Näther, R. Herges

FULL PAPER

(4.71) nm. C₅₈H₆₈N₆(848.55): calcd. C 82.03, H 8.07, N 9.90;

found C 82.16, H 8.45, N 9.99.

cm^–1. UV (toluene): λ_max(lgε) = 362 (4.44), 337 (4.47), 297 (4.63)

nm. C₅₈H₆₈F₃N₅(891.54): calcd. C 78.08, H 7.68, N 7.85; found C

77.90, H 7.98, N 8.02.

(E)-12c-[4-(4-Methylphenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-

octyl-4,8,12-triazatriangulene (9b): Following the general method 2,

(E)-12c-[4-(4-Hexylphenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-

KOH (300 mg, 5.36 mmol) was added to a solution of 23 (126 mg, propyl-4,8,12-triazatriangulene (11a): Following the general method

0.43 mmol) in 30 mL THF. After 20 min of sonication, 1b (300 mg,

0.43 mmol) was added and the mixture was sonicated for 4 h. After

2 recrystallizations from diethyl ether, 9b (130 mg, 36%) was ob-

tained as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ

2, KOH (200 mg, 3.57 mmol) was added to a solution of 25 (90 mg,

0.25 mmol) in 30 mL THF. After 30 min of sonication, 1a (124 mg,

0.25 mmol) was added and the mixture was sonicated for 4 h. After

recrystallization from diethyl ether, 11a (120 mg, 69 %) was ob-

3

= 7.75 (d, J = 8.3 Hz, 2 H, 53-H, 57-H), 7.65 (d, J = 8.7 Hz, 2 tained as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ

3

H, 48-H, 50-H), 7.26 (d, J = 8.3 Hz, 2 H, 54-H, 56-H), 7.22 (d, J

= 7.76 (d, J = 8.4 Hz, 2 H, 38-H, 42-H), 7.65 (d, J = 8.7 Hz, 2

3

= 8.7 Hz, 2 H, 47-H, 51-H), 7.20 (t, J = 8.2 Hz, 3 H, 5-H, 11-H, H, 33-H, 35-H), 7.27 (d, J = 8.5 Hz, 2 H, 39-H, 41-H), 7.22 (d, J

17-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-

H), 3.93 (t, J = 7.8 Hz, 6 H, 20-H, 28-H, 36-H), 2.40 (s, 3 H, 58- 17-H), 6.54 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-

3

= 8.7 Hz, 2 H, 32-H, 36-H), 7.19 (t, J = 8.3 Hz, 3 H, 5-H, 11-H,

3

H), 1.83 (quint, J = 7.5 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint,

H), 3.90 (t, ³J = 7.8 Hz, 6 H, 20-H, 23-H, 26-H), 2.65 (t, ³J =

³J = 7.6 Hz, 6 H, 22-H, 30-H, 38-H), 1.37 (quint, ³J = 7.4 Hz, 6

7.7 Hz, 2 H, 43-H) 1.87 (sext, ³J = 7.7 Hz, 6 H, 21-H, 24-H, 27-

3

H, 23-H, 31-H, 39-H), 1.32–1.22 (m, 18 H, 24-H, 25-H, 26-H, 32- H), 1.63 (quint, J = 7.3 Hz, 2 H, 44-H), 1.36–1.27 (m, 6 H, 45-H,

3

H, 33-H, 34-H, 40-H, 41-H, 42-H), 0.87 (t, J = 6.9 Hz, 9 H, 27-

46-H, 47-H), 1.05 (t, J = 7.4 Hz, 9 H, 22-H, 25-H, 28-H), 0.87 (t,

H, 35-H, 43-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = ³J = 7.0 Hz, 3 H, 48-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃,

151.20 (C-49), 150.76 (C-52), 141.57 (C-55), 140.50 (C-3, C-7, C-9, 25 °C): δ = 151.26 (C-34), 150.92 (C-37), 146.64 (C-40), 140.56 (C-

C-13, C-15, C-19), 132.41 (C-47, C-51), 129.71 (C-54, C-56), 128.25 3, C-7, C-9, C-13, C-15, C-19), 132.31 (C-32, C-36), 129.08 (C-39,

(C-5, C-11, C-17), 126.59 (C-46), 122.80 (C-53, C-57), 122.21 (C- C-41), 128.25 (C-5, C-11, C-17), 126.57 (C-31), 122.82 (C-38, C-

48, C-50), 109.96 (C-2, C-8, C-14), 104.93 (C-4, C-6, C-10, C-12,

42), 122.23 (C-33, C-35), 110.09 (C-2, C-8, C-14), 105.03 (C-4, C-

C-16, C-18), 96.00 (C-44), 83.55 (C-45), 46.51 (C-20, C-28, C-36), 6, C-10, C-12, C-16, C-18), 96.04 (C-29), 83.54 (C-30), 48.08 (C-

31.86 (C-25, C-33, C-41), 29.41 (C-23, C-31, C-39), 29.34 (C-24, C- 20, C-23, C-26), 35.89 (C-43), 31.69 (C-46), 31.22 (C-44), 28.93 (C-

32, C-40), 28.19 (C-1), 27.02 (C-22, C-30, C-38), 25.84 (C-21, C- 45), 28.23 (C-1), 22.59 (C-47), 19.17 (C-21, C-24, C-27), 14.08 (C-

29, C-37), 22.66 (C-26, C-34, C-42), 21.49 (C-58), 14.18 (C-27, C- 48), 11.20 (C-22, C-25, C-28) ppm. MS (EI, 70 eV): m/z (%) = 697

35, C-43) ppm. MS (MALDI-TOF, Cl-CCA): m/z = 837 [M]⁺. IR (1), 408 (54), 365 (71), 290 (74), 161 (100), 101 (71). IR (ATR): ν

˜

(ATR): ν = 3098 (w), 3026 (w), 2952 (m), 2922 (s), 2851 (m), 1613

= 3017 (w), 2950 (m), 2922 (m), 2854 (m), 2360 (s), 1608 (s), 1578

˜

(s), 1579 (vs), 1480 (s), 1455 (vs), 1393 (s), 1370 (s), 1244 (s), 1168 (s), 1480 (s), 1453 (s), 1389 (s), 1229 (s), 1132 (s), 844 (s), 749 (s),

(s), 1153 (s), 848 (m), 768 (m), 751 (m), 725 (m), 696 (m), 555 (m) 695 (s), 557 (m) cm^–1. UV (toluene): λ_max(lgε) = 346 (4.61) nm.

cm^–1. UV (toluene): λ_max(lgε) = 355 (4.53), 337 (4.54), 296 (4.70)

nm. C₅₈H₇₁N₅(837.57): calcd. C 83.11, H 8.54, N 8.36; found C

82.85, H 8.78, N 8.39.

C₄₈H₅₁N₅(697.41): calcd. C 82.60, H 7.37, N 10.03; found C 82.53,

H 7.51, N 10.12.

(E)-12c-[4-(4-Hexylphenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-octyl-

4,8,12-triazatriangulene (11b): Following the general method 2,

KOH (300 mg, 5.36 mmol) was added to a solution of 25 (156 mg,

0.43 mmol) in 30 mL THF. After 20 min of sonication, 1b (300 mg,

0.43 mmol) was added and the mixture was sonicated for 4 h. After

recrystallization from ethanol, 11b (150 mg, 38%) was obtained as

an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C): δ = 7.76

(E)-12c-{4-[4-(Trifluoromethyl)phenyldiazenyl]phenyl}ethynyl-

4,8,12-tri-n-octyl-4,8,12-triazatriangulene (10b): Following the ge-

neral method 2, KOH (300 mg, 5.36 mmol) was added to a solution

of 24 (149 mg, 0.43 mmol) in 30 mL THF. After 20 min of sonic-

ation, 1b (300 mg, 0.43 mmol) was added and the mixture was soni-

cated for 4 h. After recrystallization from ethanol, 10b (200 mg,

52 %) was obtained as an orange solid. ¹H NMR (500.1 MHz,

3

(d, J = 8.4 Hz, 2 H, 53-H, 57-H), 7.65 (d, J = 8.6 Hz, 2 H, 48-

CDCl₃, 25 °C): δ = 7.92 (d, ³J = 8.3 Hz, 2 H, 53-H, 57-H), 7.73 (d, H, 50-H), 7.27 (d, ³J = 8.5 Hz, 2 H, 54-H, 56-H), 7.22 (d, ³J =

³J = 8.5 Hz, 2 H, 54-H, 56-H), 7.70 (d, ³J = 8.7 Hz, 2 H, 48-H, 50-

8.6 Hz, 2 H, 47-H, 51-H), 7.20 (t, J = 8.3 Hz, 3 H, 5-H, 11-H, 17-

3

H), 7.25 (d, J = 8.0 Hz, 2 H, 47-H, 51-H), 7.20 (t, J = 8.2 Hz, 3

H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H),

3

H, 5-H, 11-H, 17-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H,

3.94 (t, J = 7.8 Hz, 6 H, 20-H, 28-H, 36-H), 2.65 (t, J = 7.7 Hz,

12-H, 16-H, 18-H), 3.93 (t, J = 7.8 Hz, 6 H, 20-H, 28-H, 36-H), 2 H, 58-H), 1.83 (quint, ³J = 7.5 Hz, 6 H, 21-H, 29-H, 37-H), 1.63

3

1.83 (quint, ³J = 7.5 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint, ³J = (quint, J = 7.4 Hz, 2 H, 59-H), 1.45 (quint, J = 7.7 Hz, 6 H, 22-

3

7.7 Hz, 6 H, 22-H, 30-H, 38-H), 1.37 (quint, J = 7.5 Hz, 6 H, 23-

H, 30-H, 38-H), 1.40–1.33 (m, 6 H, 23-H, 31-H, 39-H), 1.33–1.22

H, 31-H, 39-H), 1.32–1.22 (m, 18 H, 24-H, 25-H, 26-H, 32-H, 33- (m, 24 H, 24-H, 25-H, 26-H, 32-H, 33-H, 34-H, 40-H, 41-H, 42-

3

H, 34-H, 40-H, 41-H, 42-H), 0.87 (t, J = 6.9 Hz, 9 H, 27-H, 35-

H, 60-H, 61-H, 62-H), 0.87 (t, J = 6.8 Hz, 12 H, 27-H, 35-H, 43-

H, 43-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 154.41

(C-52), 150.88 (C-49), 140.51 (C-3, C-7, C-9, C-13, C-15, C-19),

132.48 (C-47, C-51), 131.99 (C-55), 128.31 (C-5, C-11, C-17),

H, 63-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 151.27

(C-49), 150.96 (C-52), 146.60 (C-55), 140.52 (C-3, C-7, C-9, C-13,

C-15, C-19), 132.36 (C-47, C-51), 129.11 (C-54, C-56), 128.25 (C-

127.84 (C-46), 126.25 (C-54, C-56), 122.94 (C-53, C-57), 122.65 (C- 5, C-11, C-17), 126.59 (C-46), 122.81 (C-53, C-57), 122.21 (C-48,

48, C-50), 109.85 (C-2, C-8, C-14), 104.96 (C-4, C-6, C-10, C-12, C-50), 110.02 (C-2, C-8, C-14), 104.95 (C-4, C-6, C-10, C-12, C-

C-16, C-18), 96.86 (C-44), 83.42 (C-45), 46.50 (C-20, C-28, C-36), 16, C-18), 96.02 (C-44), 83.57 (C-45), 46.53 (C-20, C-28, C-36),

31.86 (C-25, C-33, C-41), 29.42 (C-23, C-31, C-39), 29.34 (C-24, C- 35.90 (C-58), 31.86 (C-25, C-33, C-41), 31.69 (C-61), 31.22 (C-59),

32, C-40), 28.28 (C-1), 27.02 (C-22, C-30, C-38), 25.84 (C-21, C- 29.41 (C-23, C-31, C-39), 29.34 (C-24, C-32, C-40), 28.93 (C-60),

29, C-37), 22.66 (C-26, C-34, C-42), 14.12 (C-27, C-35, C-43) ppm. 28.22 (C-1), 27.03 (C-22, C-30, C-38), 25.87 (C-21, C-29, C-37),

MS (MALDI-TOF, Cl-CCA): m/z = 891 [M]⁺. IR (ATR): ν = 3102

(w), 3028 (w), 2954 (m), 2923 (s), 2852 (m), 1614 (s), 1579 (s), 1481

(s), 1456 (s), 1393 (s), 1320 (vs), 1244 (s), 1166 (vs), 1128 (vs), 1101

22.66 (C-26, C-34, C-42), 22.59 (C-62), 14.12 (C-27, C-35, C-43),

˜

14.07 (C-63) ppm. MS (MALDI-TOF, Cl-CCA): m/z = 907 [M]⁺.

IR (ATR): ν = 3031 (w), 2954 (m), 2923 (s), 2852 (m), 1614 (s),

˜

(s), 1064 (s), 1012 (m), 852 (s), 763 (s), 751 (s), 703 (s), 598 (m) 1579 (vs), 1481 (s), 1456 (vs), 1393 (s), 1371 (s), 1264 (m), 1244 (s),

5052

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Eur. J. Org. Chem. 2010, 5041–5055

Triazatriangulenes for Photo-Switchable Self-Assembled Monolayers

1168 (s), 1153 (s), 849 (s), 753 (s), 723 (s), 697 (s), 563 (m) cm^–1. (vs), 1482 (vs), 1455 (vs), 1392 (s), 1266 (s), 1244 (s), 1168 (s), 1150

UV (toluene): λ_max(lgε) = 357 (4.62), 345 (4.62), 296 (4.72) nm.

(s), 1101 (s), 990 (m), 847 (s), 797 (m), 759 (m), 746 (m), 729 (s),

C₆₃H₈₁N₅(907.65): calcd. C 83.30, H 8.99, N 7.71; found C 83.26, 693 (m), 598 (m), 554 (m) cm^–1. UV (toluene): λ_max(lgε) = 367

H 9.53, N 7.79.

(4.58), 336 (4.51), 296 (4.78) nm. C₅₈H₆₈D₃N₅O (856.58): calcd. C

81.26, H 8.70, N 8.17; found C 80.79, H 8.79, N 8.37.

(E)-12c-[4-(4-Methoxyphenyldiazenyl)phenyl]ethynyl-4,8,12-tri-n-

octyl-4,8,12-triazatriangulene (12b): Following the general method

2, KOH (600 mg, 10.7 mmol) was added to a solution of 34

(265 mg, 0.86 mmol) in 40 mL THF. After 20 min of sonication, 1b

(600 mg, 0.86 mmol) was added and the mixture was sonicated for

4 h. After recrystallization from ethanol, 12b (397 mg, 54%) was

obtained as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C):

(E)-12c-[4-(3,5-Dimethylphenyldiazenyl)phenyl]ethynyl-4,8,12-tri-

n-propyl-4,8,12-triazatriangulene (14a): Following the general

method 2, KOH (200 mg, 3.57 mmol) was added to a solution of

26 (187 mg, 0.61 mmol) in 20 mL THF. After 60 min of sonication,

1a (300 mg, 0.61 mmol) was added and the mixture was sonicated

for 5 h. After recrystallization from diethyl ether, 14a (250 mg,

64 %) was obtained as an orange solid. ¹H NMR (500.1 MHz,

3

δ = 7.84 (d, J = 9.1 Hz, 2 H, 53-H, 57-H), 7.62 (d, J = 8.6 Hz, 2

3

H, 48-H, 50-H), 7.21 (d, J = 8.7 Hz, 2 H, 47-H, 51-H), 7.19 (t, J

3

CDCl₃, 25 °C): δ = 7.65 (d, J = 8.6 Hz, 2 H, 33-H, 35-H), 7.46 (s,

3

= 8.3 Hz, 3 H, 5-H, 11-H, 17-H), 6.96 (d, J = 9.1 Hz, 2 H, 54-H,

3

2 H, 38-H, 42-H), 7.22 (d, J = 8.6 Hz, 2 H, 32-H, 36-H), 7.19 (t,

3

56-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-

³J = 8.2 Hz, 3 H, 5-H, 11-H, 17-H), 7.08 (s, 1 H, 40-H), 6.54 (d,

³J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-H, 16-H, 18-H), 3.90 (t, ³J =

7.8 Hz, 6 H, 20-H, 23-H, 26-H), 2.37 (s, 6 H, 43-H, 44-H), 1.87

3

H), 3.93 (t, J = 7.8 Hz, 6 H, 20-H, 28-H, 36-H), 3.86 (s, 3 H, 58-

3

H), 1.83 (quint, J = 7.6 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint,

³J = 7.6 Hz, 6 H, 22-H, 30-H, 38-H), 1.36 (quint, ³J = 7.5 Hz, 6

H, 23-H, 31-H, 39-H), 1.32–1.21 (m, 18 H, 24-H, 25-H, 26-H, 32-

3

(sext, J = 7.6 Hz, 6 H, 21-H, 24-H, 27-H), 1.05 (t, J = 7.4 Hz, 9

H, 22-H, 25-H, 28-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C):

δ = 152.86 (C-37), 151.24 (C-34), 140.56 (C-3, C-7, C-9, C-13, C-

15, C-19), 138.72 (C-39, C-41), 132.73 (C-40), 132.32 (C-32, C-36),

128.26 (C-5, C-11, C-17), 126.72 (C-31), 122.26 (C-33, C-35),

120.61 (C-38, C-42), 110.08 (C-2, C-8, C-14), 105.03 (C-4, C-6, C-

10, C-12, C-16, C-18), 96.13 (C-29), 83.52 (C-30), 48.09 (C-20, C-

23, C-26), 28.23 (C-1), 21.22 (C-43, C-44), 19.17 (C-21, C-24, C-

27), 11.19 (C-22, C-25, C-28) ppm. MS (MALDI-TOF, Cl-CCA):

3

H, 33-H, 34-H, 40-H, 41-H, 42-H), 0.87 (t, J = 6.7 Hz, 9 H, 27-

H, 35-H, 43-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃): δ = 162.08

(C-55), 151.28 (C-49), 147.06 (C-52), 140.52 (C-3, C-7, C-9, C-13,

C-15, C-19), 132.35 (C-47, C-51), 128.24 (C-5, C-11, C-17), 126.23

(C-46), 124.72 (C-53, C-57), 122.05 (C-48, C-50), 114.20 (C-54, C-

56), 110.05 (C-2, C-8, C-14), 104.95 (C-4, C-6, C-10, C-12, C-16,

C-18), 95.84 (C-44), 83.61 (C-45), 55.57 (C-58), 46.53 (C-20, C-28,

C-36), 31.86 (C-25, C-33, C-41), 29.42 (C-23, C-31, C-39), 29.34

(C-24, C-32, C-40), 28.20 (C-1), 27.03 (C-22, C-30, C-38), 25.88

(C-21, C-29, C-37), 22.66 (C-26, C-34, C-42), 14.12 (C-27, C-35,

C-43) ppm. MS (MALDI-TOF, Cl-CCA): m/z = 853 [M]⁺. IR

m/z = 641 [M]⁺. IR (ATR): ν = 3018 (w), 2956 (m), 2864 (m), 1611

˜

(s), 1578 (s), 1482 (s), 1455 (s), 1390 (s), 1228 (s), 1168 (s), 1143 (s),

986 (m), 918 (m), 840 (m), 752 (s), 707 (s), 684 (m), 659 (s), 531

(m) cm^–1. UV (toluene): λ_max(lgε) = 358 (4.55), 336 (4.58) nm.

C₄₄H₄₃N₅(641.35): calcd. C 82.34, H 6.75, N 10.91; found C 82.63,

H 6.94, N 10.75.

(ATR): ν = 3095 (w), 3025 (w), 2954 (m), 2923 (s), 2851 (s), 1613

˜

(s), 1579 (vs), 1481 (s), 1455 (vs), 1391 (s), 1370 (s), 1245 (vs), 1168

(s), 1149 (s), 1138 (s), 1103 (m), 1028 (m), 848 (s), 836 (m), 748 (s),

731 (m), 695 (m), 603 (m), 556 (s) cm^–1. UV (toluene): λ_max(lgε)

= 368 (4.54), 336 (4.46), 296 (4.70) nm. C₅₈H₇₁N₅O (853.57): calcd.

C 81.55, H 8.38, N 8.20; found C 81.00, H 8.85, N 8.37.

(E)-12c-[4-(3,5-Di-tert-butylphenyldiazenyl)phenyl]ethynyl-4,8,12-

tri-n-propyl-4,8,12-triazatriangulene (15a): Following the general

method 2, KOH (300 mg, 5.36 mmol) was added to a solution of

27 (238 mg, 0.61 mmol) in 30 mL THF. After 20 min of sonication,

1a (300 mg, 0.61 mmol) was added and the mixture was sonicated

for 4 h. After recrystallization from diethyl ether, 15a (206 mg,

47 %) was obtained as an orange solid. ¹H NMR (500.1 MHz,

CDCl₃, 25 °C): δ = 7.71 (d, ⁴J = 1.8 Hz, 2 H, 38-H, 42-H), 7.67 (d,

³J = 8.5 Hz, 2 H, 33-H, 35-H), 7.53 (t, ⁴J = 1.8 Hz, 1 H, 40-H),

(E)-12c-{4-[4-([D₃]Methoxy)phenyldiazenyl]phenyl}ethynyl-4,8,12-

tri-n-octyl-4,8,12-triazatriangulene (13b): Following the general

method 2, KOH (600 mg, 10.7 mmol) was added to a solution of

35 (268 mg, 0.86 mmol) in 40 mL THF. After 20 min of sonication,

1b (600 mg, 0.86 mmol) was added and the mixture was sonicated

for 4 h. After two recrystallizations from ethanol, 13b (413 mg,

56 %) was obtained as an orange solid. ¹H NMR (500.1 MHz,

3

7.23 (d, J = 8.5 Hz, 2 H, 32-H, 36-H), 7.19 (t, J = 8.3 Hz, 3 H,

CDCl₃, 25 °C): δ = 7.84 (d, ³J = 9.0 Hz, 2 H, 53-H, 57-H), 7.62 (d, 5-H, 11-H, 17-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-

3

³J = 8.5 Hz, 2 H, 48-H, 50-H), 7.21 (d, ³J = 8.6 Hz, 2 H, 47-H, 51-

H, 16-H, 18-H), 3.90 (t, ³J = 7.8 Hz, 6 H, 20-H, 23-H, 26-H), 1.87

H), 7.19 (t, ³J = 8.3 Hz, 3 H, 5-H, 11-H, 17-H), 6.96 (d, ³J = (sext, ³J = 7.7 Hz, 6 H, 21-H, 24-H, 27-H), 1.36 (s, 18 H, 44-H,

9.0 Hz, 2 H, 54-H, 56-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10- 45-H, 46-H, 48-H, 49-H, 50-H), 1.05 (t, ³J = 7.4 Hz, 9 H, 22-H,

3

H, 12-H, 16-H, 18-H), 3.93 (t, J = 7.7 Hz, 6 H, 20-H, 28-H, 36-

25-H, 28-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ =

3

H), 1.83 (quint, J = 7.0 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint, 152.59 (C-37), 151.79 (C-39, C-41), 151.37 (C-34), 140.57 (C-3, C-

³J = 7.3 Hz, 6 H, 22-H, 30-H, 38-H), 1.37 (quint, ³J = 7.5 Hz, 6

7, C-9, C-13, C-15, C-19), 132.32 (C-32, C-36), 128.26 (C-5, C-11,

H, 23-H, 31-H, 39-H), 1.32–1.21 (m, 18 H, 24-H, 25-H, 26-H, 32- C-17), 126.53 (C-31), 125.37 (C-40), 122.24 (C-33, C-35), 117.29

3

H, 33-H, 34-H, 40-H, 41-H, 42-H), 0.87 (t, J = 6.7 Hz, 9 H, 27-

(C-38, C-42), 110.10 (C-2, C-8, C-14), 105.04 (C-4, C-6, C-10, C-

H, 35-H, 43-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ = 12, C-16, C-18), 95.98 (C-29), 83.54 (C-30), 48.10 (C-20, C-23, C-

162.08 (C-55), 151.28 (C-49), 147.04 (C-52), 140.52 (C-3, C-7, C-9, 26), 35.08 (C-43, C-47), 31.43 (C-44, C-45, C-46, C-48, C-49, C-

C-13, C-15, C-19), 132.35 (C-47, C-51), 128.25 (C-5, C-11, C-17), 50), 28.23 (C-1), 19.18 (C-21, C-24, C-27), 11.21 (C-22, C-25, C-

126.22 (C-46), 124.73 (C-53, C-57), 122.05 (C-48, C-50), 114.19 (C- 28) ppm. MS (EI, 70 eV): m/z (%) = 725 (3), 408 (7), 365 (3), 318

54, C-56), 110.03 (C-2, C-8, C-14), 104.95 (C-4, C-6, C-10, C-12,

(39), 189 (100), 133 (32), 101 (42). UV (toluene): λ_max(lgε) = 352

C-16, C-18), 95.84 (C-44), 83.62 (C-45), 46.53 (C-20, C-28, C-36), (4.50), 336 (4.53), 296 (4.71) nm. IR (ATR): ν = 3098 (w), 3028

˜

31.87 (C-25, C-33, C-41), 29.42 (C-23, C-31, C-39), 29.35 (C-24, C- (w), 2962 (m), 2873 (m), 1614 (s), 1579 (s), 1482 (s), 1456 (s), 1392

32, C-40), 28.19 (C-1), 27.03 (C-22, C-30, C-38), 25.88 (C-21, C- (s), 1364 (m), 1270 (m), 1230 (s), 1170 (s), 1145 (s), 1098 (m), 988

29, C-37), 22.67 (C-26, C-34, C-42), 14.13 (C-27, C-35, C-43) ppm. (m), 918 (m), 889 (m), 843 (m), 754 (s), 710 (s), 654 (m), 539 (m)

MS (MALDI-TOF, Cl-CCA): m/z = 856 [M]⁺. IR (ATR): ν = 3079

cm^–1. C₅₀H₅₅N₅(725.45): calcd. C 82.72, H 7.64, N 9.65; found C

˜

(w), 3031 (w), 2954 (m), 2924 (s), 2852 (m), 2069 (w), 1614 (s), 1579 82.63, H 7.46, N 9.82.

Eur. J. Org. Chem. 2010, 5041–5055

www.eurjoc.org

5053

J. Kubitschke, C. Näther, R. Herges

FULL PAPER

(E)-12c-[4-(3,5-Di-tert-butylphenyldiazenyl)phenyl]ethynyl-4,8,12-

tri-n-octyl-4,8,12-triazatriangulene (15 b): Following the general

method 2, KOH (300 mg, 5.36 mmol) was added to a solution of

27 (157 mg, 0.43 mmol) in 30 mL THF. After 20 min of sonication,

1b (300 mg, 0.43 mmol) was added and the mixture was sonicated

for 4 h. After recrystallization from diethyl ether, 15b (196 mg,

49 %) was obtained as an orange solid. ¹H NMR (500.1 MHz,

CDCl₃, 25 °C): δ = 7.70 (d, ⁴J = 1.8 Hz, 2 H, 53-H, 57-H), 7.67 (d,

³J = 8.6 Hz, 2 H, 48-H, 50-H), 7.52 (t, ⁴J = 1.8 Hz, 1 H, 55-H),

1165 (s), 1139 (m), 991 (m), 915 (m), 822 (s), 761 (vs), 721 (s), 686

(s), 542 (m) cm^–1. UV (toluene): λ_max(lgε) = 355 (4.65) nm.

C₆₃H₇₃N₅(899.59): calcd. C 84.05, H 8.17, N 7.78; found C 84.08,

H 8.68, N 7.94.

Supporting Information (see also the footnote on the first page of

this article): Numbered structures of the synthesized molecules for

the assignment of NMR signals.

3

7.23 (d, J = 8.7 Hz, 2 H, 47-H, 51-H), 7.20 (t, J = 8.3 Hz, 3 H,

Acknowledgments

3

5-H, 11-H, 17-H), 6.55 (d, J = 8.3 Hz, 6 H, 4-H, 6-H, 10-H, 12-

H, 16-H, 18-H), 3.93 (t, ³J = 7.8 Hz, 6 H, 20-H, 28-H, 36-H), 1.87

(quint, ³J = 7.6 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint, ³J =

7.9 Hz, 6 H, 22-H, 30-H, 38-H), 1.36 (s, 18 H, 59-H, 60-H, 61-H,

63-H, 64-H, 65-H), 1.33–1.22 (m, 24 H, 23-H, 24-H, 25-H, 26-H,

31-H, 32-H, 33-H, 34-H, 39-H, 40-H, 41-H, 42-H), 0.87 (t, ³J =

6.9 Hz, 9 H, 27-H, 35-H, 43-H) ppm. ¹³C NMR (125.8 MHz,

CDCl₃, 25 °C): δ = 152.60 (C-52), 151.76 (C-54, C-56), 151.35 (C-

49), 140.51 (C-3, C-7, C-9, C-13, C-15, C-19), 132.34 (C-47, C-51),

128.25 (C-5, C-11, C-17), 126.52 (C-46), 125.32 (C-55), 122.21 (C-

48, C-50), 117.25 (C-53, C-57), 110.01 (C-2, C-8, C-14), 104.94 (C-

4, C-6, C-10, C-12, C-16, C-18), 95.93 (C-44), 83.57 (C-45), 46.52

(C-20, C-28, C-36), 35.06 (C-58, C-62), 31.87 (C-25, C-33, C-41),

31.41 (C-59, C-60, C-61, C-63, C-64, C-65), 29.41 (C-23, C-31, C-

39), 29.34 (C-24, C-32, C-40), 28.23 (C-1), 27.02 (C-22, C-30, C-

38), 25.86 (C-21, C-29, C-37), 22.66 (C-26, C-34, C-42), 14.12 (C-

27, C-35, C-43) ppm. MS (MALDI-TOF, Cl-CCA): m/z = 935

This work was supported by the Deutsche Forschungsgemeinschaft

(DFG) via SFB 677.

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[M]⁺. IR (ATR): ν = 3098 (w), 3028 (w), 2955 (m), 2922 (s), 2852

1624–1626.

˜

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(m), 1615 (s), 1579 (vs), 1480 (s), 1456 (vs), 1393 (s), 1372 (s), 1262

(m), 1244 (s), 1212 (m), 1168 (s), 1144 (m), 848 (m), 757 (s), 713

(s), 699 (m), 654 (m) cm^–1. UV (toluene): λ_max(lgε) = 352 (4.52),

337 (4.55), 296 (4.68) nm. C₆₅H₈₅N₅(935.68): calcd. C 83.37, H

9.15, N 7.48; found C 82.89, H 9.53, N 7.65.

(E)-12c-{4-[4-(Phenyldiazenyl)phenyl]phenyl}ethynyl-4,8,12-tri-n-

octyl-4,8,12-triazatriangulene (16b): Following the general method

2, KOH (300 mg, 5.36 mmol) was added to a solution of 40

(152 mg, 0.43 mmol) in 30 mL THF. After 20 min of sonication, 1b

(300 mg, 0.43 mmol) was added and the mixture was sonicated for

5 h. After recrystallization from ethanol, 16b (269 mg, 69%) was

obtained as an orange solid. ¹H NMR (500.1 MHz, CDCl₃, 25 °C):

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3

δ = 7.93 (d, J = 8.5 Hz, 2 H, 54-H, 56-H), 7.91 (d, J = 8.2 Hz, 2

3

H, 59-H, 63-H), 7.63 (d, J = 8.5 Hz, 2 H, 53-H, 57-H), 7.53–7.44

3

(m, 3 H, 60-H, 61-H, 62-H), 7.40 (d, J = 8.3 Hz, 2 H, 48-H, 50-

H), 7.20 (t, ³J = 8.2 Hz, 3 H, 5-H, 11-H, 17-H), 7.19 (d, ³J =

3

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H, 12-H, 16-H, 18-H), 3.93 (t, J = 7.8 Hz, 6 H, 20-H, 28-H, 36-

3

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H), 1.84 (quint, J = 7.5 Hz, 6 H, 21-H, 29-H, 37-H), 1.46 (quint,

³J = 7.7 Hz, 6 H, 22-H, 30-H, 38-H), 1.37 (quint, ³J = 7.4 Hz, 6

H, 23-H, 31-H, 39-H), 1.33–1.23 (m, 18 H, 24-H, 25-H, 26-H, 32-

3

H, 33-H, 34-H, 40-H, 41-H, 42-H), 0.87 (t, J = 6.9 Hz, 9 H, 27-

H, 35-H, 43-H) ppm. ¹³C NMR (125.8 MHz, CDCl₃, 25 °C): δ =

152.73 (C-58), 151.73 (C-55), 143.00 (C-52), 140.49 (C-3, C-7, C-9,

C-13, C-15, C-19), 138.78 (C-49), 132.13 (C-47, C-51), 130.97 (C-

61), 129.08 (C-60, C-62), 128.18 (C-5, C-11, C-17), 127.48 (C-53,

C-57), 126.35 (C-48, C-50), 123.71 (C-46), 123.34 (C-54, C-56),

122.85 (C-59, C-63), 110.14 (C-2, C-8, C-14), 104.91 (C-4, C-6, C-

10, C-12, C-16, C-18), 94.72 (C-44), 83.39 (C-45), 46.51 (C-20, C-

28, C-36), 31.87 (C-25, C-33, C-41), 29.42 (C-23, C-31, C-39), 29.34

(C-24, C-32, C-40), 28.07 (C-1), 27.03 (C-22, C-30, C-38), 25.86

(C-21, C-29, C-37), 22.66 (C-26, C-34, C-42), 14.11 (C-27, C-35,

C-43) ppm. MS (MALDI-TOF, Cl-CCA): m/z = 899 [M]⁺. IR

(ATR): ν = 3028 (w), 2953 (m), 2919 (s), 2850 (s), 1612 (s), 1579

˜

(vs), 1483 (vs), 1455 (vs), 1392 (s), 1368 (s), 1265 (m), 1244 (s),

5054

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Eur. J. Org. Chem. 2010, 5041–5055

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Received: May 7, 2010

Published Online: July 27, 2010

Eur. J. Org. Chem. 2010, 5041–5055

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5055

Article Doi

Synthesis of functionalized triazatriangulenes for application in photo- Switchable self-assembled monolayers

DOI: 10.1002/ejoc.201000650

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