Electrostatics and color: Massive electrostatic perturbation of chromophores by ion cluster ligands

Article abstract of DOI:10.1021/ja064907u

The SASAPOS protocol, a general reaction sequence allowing complete exchange of various neutral ligands X in organic, elementorganic, and inorganic systems by cationic ligands L⁺, has been applied to a variety of pentafluorophenyl-substituted d

Full text of DOI:10.1021/ja064907u

Published on Web 12/29/2006
Electrostatics and Color: Massive Electrostatic Perturbation
of Chromophores by Ion Cluster Ligands
Robert Weiss* and Frank G. Pu¨hlhofer
Contribution from the Institut fu¨r Organische Chemie, UniVersita¨t Erlangen-Nu¨rnberg,
Henkestrasse 42, D-91054 Erlangen, Germany
Received July 11, 2006; E-mail: robert.weiss@chemie.uni-erlangen.de
Abstract: The SASAPOS protocol, a general reaction sequence allowing complete exchange of various
neutral ligands X in organic, elementorganic, and inorganic systems by cationic ligands L+, has been applied
to a variety of pentafluorophenyl-substituted dyes of the general formula C6F5-XdY-D (X, Y ) N, CH; D
) donor substituted arene), yielding the corresponding polycationically substituted dyes. The perturbation
of the chromophores by the massive electrostatic effects introduced via the SASAPOS method led to
bathochromic shifts of the absorption maxima of up 140 nm, 7600 cm-1, respectively. A strong dependency
of the specific shifts on the nature of the connecting π linker -XdY- (N vs CH) has been detected by
UV-vis absorption spectroscopy. Additionally, the effects of resubstitution of cationic ligands L+ by OH
and O- have been studied.
Introduction
Following this strategy, several known and hitherto unknown
pentafluoro azo arenes 8a-f were synthesized6 and “sasaposed”
In recent work we have presented evidence that the penta-
kisonio-substituted phenyl anion derivative 2 can act as a potent
leaving group in heteropolar C-X disconnections (X ) C, P,
and H) according to Scheme 1.1,2
We figured that systems of type 2 should be representatives
of a new class of sterically highly demanding and electronically,
strongly accepting ligands. As they are composed of a polycation
in close association with a neutralizing sphere of anions, we
have termed systems of type 2 ion cluster ligands (IC ligands).
We have introduced a variety of IC ligand precursors and IC
ligand-substituted templates in previous work.1-5
to yield the novel polycationic dye salts 9a-f and 10 according
to Scheme 3.
All compounds (cf. Scheme 3) were fully characterized by
1H and 13C NMR spectroscopy, FAB-MS, elemental analysis,
and UV-vis absorption spectroscopy.
The complete exchange of fluorine substituents against
DMAP+ ligands during the SASAPOS cascade (cf. Scheme 3)
leads to strong bathochromic shifts of the absorption maxima
of the azo dyes; e.g., shifts from yellow/orange (8) to red/violet
(9, 10) (cf. Table 1 and Figure 1 below).
What are the reasons for the dramatic red shifts (up to 140
nm, 7600 cm-1 respectively, for 9a) in the longest-wavelength
UV-vis absorptions in going from the pentafluoro phenyl
precursors 8 to the corresponding peronio substituted9 dyes 9
and 10 (cf. Table 1)?
As a first elaboration of this concept we subsequently describe
syntheses of classical azo dyes and related aldimines and
stilbenes whose chromophore is massively modified due to the
specific electronic and steric qualities of an incorporated IC
ligand.
Simple PM3 model calculations suggest that both the pen-
tafluoro phenyl as well as the pentakisonio substituents of
compounds 8 and 9, 10 respectively are completely rotated out
of conjugation with the azo chromophore. Thus, mesomeric
effects are not operative between those two π-subsystems in
both types of dyes. In particular, although highly electron-
deficient, the pentakisonio-substituted phenyl moiety in 9(10)
cannot act as an M acceptor due to this orthogonality. The latter
is a consequence of the steric requirements of the rigid ion
cluster contained in 9(10), in which all five pyridinio substituents
Results and Discussion
Experiments to introduce an IC ligand via direct nucleophilic
substitution are not very promising due to its electrostatically,
strongly reduced nucleophilicity (cf. the leaving group character
of 2)1,2 and its steric congestion. However, the desired result
can be achieved indirectly by subjecting appropriate pentafluo-
rophenyl derivatives of a substrate to the SASAPOS protocol
(self-activated silyl-assisted poly-onio-substitution),1-5 shown
in generalized form in Scheme 2.
(1) Pu¨hlhofer, F. G.; Weiss, R. Eur. J. Org. Chem. 2004, 5, 1002-1007.
(2) Huber, S. M.; Pu¨hlhofer, F. G.; Weiss, R. Eur. J. Org. Chem. 2005, 16,
3530-3535.
(6) The synthesis of pentafluoro azo arenes shown in Scheme 3 was previously
described for the syntheses of compounds 8b and 8c.7 Compound 8a was
previously known, but synthesized via a different method.8
(7) Kosynkin, D.; Bockman, T. M.; J. Kochi, J. K. J. Chem. Soc., Perkin Trans.
2 1997, 2003-2012.
(3) Weiss, R.; Pomrehn, B.; Hampel, F.; Bauer, W. Angew. Chem. 1995, 107,
1446-1448; Angew. Chem., Int. Ed. Engl. 1995, 34, 1319-1321.
(4) Weiss, R.; May, R.; Pomrehn, B. Angew. Chem. 1996, 108, 1319-1321;
Angew. Chem., Int. Ed. Engl. 1996, 35, 1232-1234.
(8) Matsui, M.; Funabiki, K.; Shibata, K. Bull. Chem. Soc. Jpn. 2002, 75, 531-
536.
(5) Weiss, R.; Pu¨hlhofer, F. G.; Jux, N.; Merz, K. Angew. Chem. 2002, 114,
3969-3971; Angew. Chem. Int. Ed. 2002, 41, 3815-3817.
(9) As is characteristic for the SASAPOS protocol, no partially onio-substituted
derivatives were formed.
9
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J. AM. CHEM. SOC. 2007, 129, 547-553
547

A R T I C L E S
Weiss and Pu¨hlhofer
Scheme 1. Formation of 2 by Heteropolar C-X Disconnections
Scheme 2. General Form of the SASAPOS Protocol
Scheme 3. Syntheses of Pentafluorophenylazo Dyes 8a-f and Subsequent SASAPOS Cascadesa
a (i) +5 DMAP, +5 TMSOTf (9a-f)/TMSI (10); -5 TMSF; PhCl, ∆; 24 h; >95%.
Table 1. UV-vis Absorption Data of Azo Dye Solutions in
As for 8, lone pair repulsion between the o-fluorines and the
azo function are responsible for the calculated deconjugation.
The principal difference between dyes of type 8 and the
corresponding “sasaposed”1,2 modifications of type 9(10) is the
pentacationic charge of the peronio-substituted phenyl substitu-
ent, whose positive electrostatic potential (somewhat attenuated
by the negative potential of the counterions) is primarily felt
by the adjacent orthogonal azo chromophore. By virtue of this
massive electrostatic effect, the longest-wavelength UV-vis
transitions in dyes 9(10) is strongly red-shifted, as this particular
UV-vis transition is connected with significant charge-transfer
from the donor substituent(s) into the azo chromophore. This
is well-known from traditional push-pull substituted azo
compounds and is also qualitatively reproduced by our model
calculations.
Acetonitrile
8
9
λ
max [nm]
λ
max [nm]
“SASAPOS-shift”
[nm] ([cm-1])
(E [cm-1])
ꢀmax
(E [cm-1])
ꢀmax
a
b
433 (23100) 25000 573 (17500) 50000 140 (5600)
317 (31500) 12000 419 (23900) 28000 102 (7600)
c
d
e
f
358 (27900) 11500 429 (23300) 20000
327 (30600) 14000 413 (24200) 22500
389 (25700) 12500 477 (21000) 30500
455 (22000) 9500 545 (18300) 22500
574 (17400) 60000
71 (4600)
86 (6400)
88 (4700)
90 (3700)
compound 10
compound 11
503 (19900) 35000
are in their turn perpendicular to the phenyl system as the central
carrier, this whole arrangement being further rigidified by five
closely associated counteranions in defined positions.3-5,10,11
We have previously shown3 that ion clusters structurally
similar to 9 undergo a selective monohydrolysis under weakly
(10) Pu¨hlhofer, F. G. Dissertation, Universita¨t Erlangen-Nu¨rnberg, 2001.
(11) These effects are also adequately modeled by PM3 calculations.
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548 J. AM. CHEM. SOC. VOL. 129, NO. 3, 2007

Electrostatics and Color
A R T I C L E S
Application of the SASAPOS protocol (cf. Scheme 1) to 12-
14 yielded the corresponding ion cluster aldimines 15 and 16
and stilbene 17 (Scheme 5).
All new compounds were fully characterized by 1H and 13
C
NMR spectroscopy, FAB-MS, elemental analysis, and UV-
vis absorption spectrsocopy.
Analysis of the UV-vis absorption spectra of 8a, 9a, and
12-14 (Schemes 3 and 5, Table 2) indicated a strong depen-
dence between “SASAPOS-shift” and the nature of atoms
forming the π-linker between donor arene and IC ligand.
The variations of the “SASAPOS-shifts” reported in Table 2
can be explained by analyzing the effects of substitution of
nitrogen atoms by CH groups. Comparison of compound pairs
8a/9a and 14/17 indicates an increase of the “SASAPOS-shift”
from 5600 cm-1 to 6600 cm-1. Substitution of the -NdN-
bridge by the less electronegative CHCH bridge leads to
decreased coefficients of π orbitals and increased coefficients
of π* orbitals on the bridging centers. Hence, the “SASAPOS-
shift” is increased by 1000 cm-1. Data of compound pair 13/
16 show that nearly the same increase of “SASAPOS-shift” (900
cm-1) is produced, if only the nitrogen atom adjacent to the
pentakisonio-substituted phenyl moiety is exchanged by a CH
group. In contrast, substitution of the other center (12/15) even
leads to a decreased “SASAPOS-shift” (3400 cm-1). The latter
two cases demonstrate the electrostatic effects induced by
SASAPOS on orbital energies. In principle, F/DMAP+ exchange
leads to electrostatically induced energetic stabilization of both
occupied and virtual orbitals. Due to Coulomb’s law, orbitals
having large coefficients close to the origin of the electrostatic
effects are much more affected than orbitals having only small
coefficients in these regions. Since coefficients of π orbitals
are larger on N atoms and coefficients of π* orbitals are larger
on CH groups, in 12/15 electrostatic effects stabilize occupied
orbitals stronger than unoccupied ones resulting in a decreased
“SASAPOS shift” (3400 cm-1) compared to 8a/9a (5600 cm-1).
In 13/16 electrostatic effects stabilize the virtual orbitals stronger
than occupied resulting in an increased “SASAPOS shift” (6500
cm-1) compared to 8a/9a (5600 cm-1).
Finally, the data in Table 1 also indicate that changing the
counteranion from triflate (9a) to iodide (10) has no measurable
effect on the absorption maximum and only a minor effect on
the molar absorption coefficient. We further tested solutions of
9a and 10 by addition of an excess of different anions (I-,
BPh4-, [Fe(CN)6]3-), and again no effect could be detected.
To analyze the solvatochromic effects of the ion cluster dyes,
we performed UV-vis absorption spectra of 9a in different
solvents.14 The λmax values range around 573 nm (acetonitrile)
within less than 10 nm and without any correlation between
shift and the solvent characteristics (e.g., ꢀ and ET(30)). Hence,
even if the IC ligands in 9a and 10 are affected by the above
modifications, UV-vis absorption spectra are not sufficiently
sensitive to detect these effects.
Figure 1. Solutions (acetonitrile) of 8a, 9a, and 11 (from left to right).
basic conditions. In the present case the isolated product resulted
from exchange of one DMAP+ ligand against a hydroxyl group,
followed by deprotonation of the latter to yield the corresponding
phenoxide compound. In a representative experiment, 9a was
refluxed in wet acetonitrile in the presence of DMAP as base
to yield the new, fully characterized dye 11 (Scheme 4). Colors
in Scheme 4 indicate the hypsochromic shift of the absorption
maximum observed in the process (cf. Table 1 and Figure 1
below).
In principle, substitution of an acceptor ligand (DMAP+) by
a donor substituent (O-) strongly decreases the electrostatic
potential of the polyonio-substituted moiety. Hence, for the
example in Scheme 4 one expects a hypsochromic shift of the
absorption maxima from 9a to 11; for detailed data, see Table
1 and Figure 1 below.
The effect of F/DMAP+ exchange on the UV-vis absorption
spectra (“SASAPOS-shift”) varies with the donor character of
the electron rich arene in the azo dye without obvious
dependency (Table 1). The “SASAPOS-shift” varies between
71 and 140 nm in terms of wavelength, 3700 cm-1 and 7600
cm-1 in terms of energy, respectively. To further confirm this,
DMAP was added to a solution of 9d in acetonitrile during an
UV-vis absorption experiment. The aim was to increase the
donor character of the OH group (in 9d) by deprotonation. In
the resulting spectrum the band of 9d at 413 nm (ꢀ ) 22500,
24200 cm-1) disappeared and a stronger new band was found
at 535 nm (ꢀ ) 26500, 18700 cm-1). Overall this modification
led to a further red-shift of 122 nm (5500 cm-1).
The λmax (503 nm; 19900 cm-1) for 11 shows that the
decrease of electrostatic potential reduces the “SASAPOS-shift”.
Instead of 140 nm (5600 cm-1) between 8a and 9a, the
“SASAPOS-shift” (70 nm; 3200 cm-1) is exactly half of this
(in nm; 60% in cm-1) (cf. Figure 1).
In addition to the variations of the electron rich arene (cf.
Scheme 2) and the electron poor ion cluster arene (cf.
compounds 10 and 11) variations (substitution of N by CH
groups) of the connecting π-linker were made (Scheme 5).
Starting materials 12-14 for the corresponding SASAPOS
cascades were previously described (13/14)12 or synthesized in
accordance to literature procedures (see exp. section) (12).13
Conclusion
A pentakisonio-substituted phenyl unit, generated in the first
synthesis of dyes 9-11 and 15-17, turned out to function as a
(13) Synthesis of 12 according to: Li, A.; Bin, X.; Zhu, S. J. Fluorine Chem.
1994, 145-148.
(14) Solvents used: water, methanol, ethanol, acetonitrile, acetone, and di-
chloromethane. ET(30) [kcal/mol] values range (in that order) from 63.1
to 41.1; ꢀ ranges from 78.39 to 8.93. Data taken from: Reichardt, C. SolVent
effects in organic chemistry; VCH: New York, 1978; Vol. 3, appendix,
pp 270-272.
(12) Pagagni, A.; Maiorana, S.; Del Buttero, P.; Perdicchia, D.; Cariati, F.;
Cariati, E.; Marcolli, W. Eur. J. Org. Chem. 2002, 1380-1384.
9
J. AM. CHEM. SOC. VOL. 129, NO. 3, 2007 549

A R T I C L E S
Weiss and Pu¨hlhofer
Scheme 4. Hydrolysis of 9a in the Presence of DMAP
Scheme 5. SASAPOS Cascades of Aldimines 12 and 13 and Stilbene 14a
a (i) +5 DMAP, +5 TMSOTf; -5 TMSF; PhCl, ∆; 2 d; >85%.
Table 2. UV-vis Absorption Data of Azo, Aldimine, and Stilbene
Dye Solutions in Acetonitrile
Experimental Section
pentafluoro precursor
max [nm]
(E [cm-1])
pentakis onio compound
max [nm]
(E [cm-1])
If not indicated otherwise, all reactions were carried out under an
N2 atmosphere in dry solvents.
λ
λ
ꢀmax
ꢀmax
“SASAPOS-shift”
General Procedure for the Syntheses of Azo Dyes 8a-f. In a
typical procedure, a solution of pentafluoroaniline (1.83 g, 10.0 mmol)
in acetonitrile (15 mL) was added dropwise to a solution of nitrosonium
tetrafluoroborate (1.17 g, 10.0 mmol) in acetonitrile (15 mL) at -30
°C over 30 min. After 1 h of additional stirring at -30 °C, the coupling
compound (40.0 mmol) was added dropwise. The resulting dye solution
was allowed to warm to room temperature. Water (50 mL) was added
after 12 h followed by extraction with dichloromethane (3 × 50 mL).
The collected organic phases were dried (MgSO4) and evaporated to
dryness. Recrystallization from methanol (8a-c) or ethanol/water (50:
50, v:v; 8d-f) yielded the pentafluoro azo dyes. Isolated yields (not
optimized, after recrystallization) ranged from 40% (8a) to 72% (8e).
8a/9a 433 (23100) 25000 573 (17500) 50000
12/15 363 (27500) 37000 415 (24100) 29000
13/16 397 (25200) 21000 534 (18700) 28000
14/17 359 (27900) 15000 470 (21300) 24000
140 (5600)
52 (3400)
137 (6500)
111 (6600)
highly effective auxochrome. Together with its counter anions
this unit may be regarded as a first representative of ion cluster
ligands. Bathochromic shifts of up to 140 nm were achieved
by transforming a pentafluorophenyl substituent into the ion
cluster ligand via the SASAPOS protocol1-5 (cf. Scheme 2) in
a one-pot synthesis in excellent yields. Due to the structural
rigidity of the pentacationically substituted phenyl moiety in
the above examples, orbital energies were massively disturbed
by the electrostatic potential of the IC ligand predominantly
via through space interactions. Due to the variable choice of
the counteranion in the SASAPOS protocol, the IC ligand
modified dyes can be synthesized as polyhalide salts (cf.
compound 10) which will show excellent solubility in water
(especially the polychloride and -bromide salts). Besides the
effect on optical characteristics, we also expect strong influences
of ion cluster ligands on a variety of properties of any template
connected to such ligands. In general those effects are increased
ionization potentials and electron affinities as well as modifica-
tions of reactivity toward nucleophiles (increased) and electro-
philes (decreased). Furthermore, this concept for the introduction
of strong electrostatic potentials is not limited to organic
templates and will be transferable to elementorganic and
inorganic templates. For the latter in particular, we expect a
distinct electrostatic stabilization of unusual (especially low)
oxidation states.
General procedure for the Syntheses of Azo Dyes 9a-f, and 10.
In a typical procedure, the corresponding pentafluorophenyl azo dye
8a-f (1.5 mmol) was added to a solution of DMAP (12 mmol) and
TMSOTf (TMSI respectively for the synthesis of 10) (9 mmol) in
chlorobenzene (25 mL). The deeply colored solution was stirred under
reflux for 24 h, whereby the product started to precipitate after 1 h.
The precipitate was filtered, washed with dichloromethane (3 × 10
mL), and dried in high vacuum. Isolated yields ranged from 95% to
quantitative.
Hydrolysis of Compound 9a. DMAP (122 mg, 1.0 mmol) was
added to a solution of 9a (321 mg, 0.2 mmol) in wet acetonitrile (25
mL). The reaction solution was stirred under reflux, whereby the color
changed from deep purple to deep red. After 12 h the solvent was fully
removed in high vacuum and dichloromethane (100 mL) was added.
The resulting suspension was stirred for 12 h to remove the formed
protonated DMAP. The precipitate was filtered, washed with dichlo-
romethane (3 × 10 mL), and dried in high vacuum to yield 74% of 11
as red-orange powder.
Synthesis of 12. Pentafluoroaniline (1.00 g, 5.47 mmol) was stirred
under reflux in SOCl2 (20 mL). The resulting yellow solution was
cooled to room temperature after gas evolution stopped. The remaining
solvent was fully removed in vacuum. Toluene (20 mL) and 4-di-
methylaminobenzaldehyde (816 mg, 5.47 mmol) were added and stirred
9
550 J. AM. CHEM. SOC. VOL. 129, NO. 3, 2007

Electrostatics and Color
A R T I C L E S
under reflux for 12 h. The solvent was removed in vacuum, and the
resulting solid was recrystallized from hot acetone. Yield 65%; yellow-
orange needles.
2-Hydroxynaphthylazopentafluorobenzene, 8f. Yield ) 47%. 1H
3
NMR (400 MHz, CDCl3): δ ) 6.69 (d, JHH ) 9.3 Hz, 1H, H3/4),
3
3
7.45 (t, JHH ) 8.2 Hz, 1H, H6/7), 7.59 (t, JHH ) 8.4 Hz, 1H, H6/7),
7.66 (d, 3JHH ) 7.8 Hz, 1H, H5/8), 7.82 (d, 3JHH ) 9.3 Hz, 1H, H3/4),
8.50 (d, 3JHH ) 8.3 Hz, 1H, H5/8), 14.99 (s, 1H, OH) ppm. 13C NMR
(100 MHz, CDCl3): δ ) 122.15 (s), 122.82 (s), 126.40 (s), 128.41 (s),
128.63 (s), 129.49 (s), 132.32 (s), 132.96 (s), 140.89 (s, C1 naphthyl),
166.14 (s, C2 naphthyl) ppm. 19F NMR (282 MHz, CDCl3): -150.84
General Procedure for the Syntheses of Aldimines 15 and 16
and Stilbene 17. In a typical procedure, the corresponding pentafluo-
rophenyl precursor 12-14 (1.0 mmol) was added to a solution of
DMAP (7 mmol) and TMSOTf (6 mmol) in chlorobenzene (25 mL).
The deeply colored solution was stirred under reflux for 2 d, whereby
the product started to precipitate after 2 h. The precipitate was filtered,
washed with dichloromethane (3 × 10 mL), and dried in high vacuum.
Isolated yields ranged from 85% to quantitative.
3
(m, 2F), -156.09 (t, | JFF| ) 21 Hz, 1F), -161.42 (m, 2F) ppm. EI
MS (70 °C): m/z ) 338(75) [M]+, 171(18) [M - C6F5]+, 143(100)
[M - N2 C6F5]+. C16H7F5N2O (338.24) + 0.5 H2O: calcd C 55.34
-
H 2.32 N 8.07; found C 55.87 H 2.42 N 7.95. UV-vis absorption
(CH3CN): 455 nm (9500).
4-Dimethylaminophenylazopentafluorobenzene, 8a. Yield ) 40%.
1H NMR (400 MHz, CDCl3): δ ) 3.11 (s, 6H, CH3), 6.71 (d, 3JHH
)
3
9.2 Hz, 2H, H3/5 phenyl), 7.84 (d, JHH ) 9.2 Hz, 2H, H2/6 phenyl)
ppm. 13C NMR (100 MHz, CDCl3): δ ) 40.24 (s, CH3), 111.27 (s,
C3/5 phenyl), 125.86 (s, C2/6 phenyl), 144.19 (s, C1 phenyl), 153.61
(s, C4 phenyl) ppm. 19F NMR (282 MHz, CDCl3): -151.50 (m, 2F),
4-Dimethylaminophenylazopentakis[4-(dimethylamino)-1-pyridinio]-
1
benzene Pentakis(triflate), 9a. Yield ) quant. H NMR (400 MHz,
CD3CN): δ ) 3.16 (s, 6H, CH3), 3.17 (s, 6H, CH3), 3.18 (s, 12H,
3
CH3), 3.23 (s, 12H, CH3), 6.72 (d, JHH ) 9.5 Hz, 2H, H3/5 phenyl),
3
3
3
-156.41 (t, | JFF| ) 21 Hz, 1F), -162.92 (m, 2F) ppm. FAB MS
6.85 (d, JHH ) 8.1 Hz, 2H, H3/5 p-DMAP), 6.87 (d, JHH ) 8.1 Hz,
(NBA): m/z ) 315 [M]+, 120 [M - N2
C6F5]+. C14H10F5N3
4H, H3/5 DMAP), 6.92 (d, 3JHH ) 8.1 Hz, 4H, H3/5 DMAP), 7.20 (d,
-
3
(315.25): calcd C 53.34 H 3.20 N 13.33; found C 53.78 H 3.31 N
3JHH ) 9.4 Hz, 2H, H2/6 phenyl), 8.16 (d, JHH ) 8.1 Hz, 6H, H2/6
3
13.05. UV-vis absorption (CH3CN): 433 nm (25000).
DMAP), 8.17 (d, JHH ) 8.1 Hz, 4H, H2/ 6 DMAP) ppm. 13C NMR
1
(100 MHz, CD3CN): δ ) 41.12 (s, CH3), 41.23 (s, CH3), 41.37 (s,
4-Methoxyphenylazopentafluorobenzene, 8b. Yield ) 43%. H
NMR (400 MHz, CDCl3): δ ) 3.89 (s, 3H, CH3), 7.00 (d, 3JHH ) 9.0
Hz, 2H, H3/5 phenyl), 7.91 (d, 3JHH ) 9.2 Hz, 2H, H2/6 phenyl) ppm.
13C NMR (100 MHz, CDCl3): δ ) 55.68 (s, CH3), 114.39 (s, C3/5
phenyl), 125.51 (s, C2/6 phenyl), 147.48 (s, C1 phenyl), 163.66 (s, C4
phenyl) ppm. 19F NMR (282 MHz, CDCl3): -150.59 (m, 2F), -153.99
CH3), 109.09 (s, C3/5 DMAP), 110.28 (s, C3/5 DMAP), 110.38 (s,
1
C3/5 p-DMAP), 113.95 (s, C3/5 phenyl), 121.84 (q, | JCF| ) 320 Hz,
CF3), 132.81 (s, C4 onio-phenyl), 134.70 (s, C2/3/5/6 onio-phenyl),
139.58 (s, C2/3/5/6 onio-phenyl), 141.17 (s, C2/6 DMAP), 141.53 (s,
C2/6 p-DMAP), 143.00 (s, C2/6 DMAP), 143.85 (s, C2/6 phenyl),
144.24 (s, C1/4 phenyl/C1 onio-phenyl), 145.78 (s, C1/4 phenyl/C1
onio-phenyl), 148.74 (s, C1/4 phenyl/C1 onio-phenyl), 157.42 (s, C4
DMAP), 157.62 (s, C4 p-DMAP), 157.71 (s, C4 DMAP) ppm. FAB
MS (NBA): m/ z ) 1426 [M - OTf]+, 1277 [M - 2OTf]+, 1144 [M
+ H - NC6H4N(CH3)2 - 2OTf]+, 1022 [M + H - DMAP - NC6H4N-
(CH3)2 - 2OTf]+. C54H60F15N13O15S5 (1576.42) + 2 H2O: calcd C
40.22 H 4.00 N 11.29 S 9.94; found C 40.10 H 4.04 N 11.14 S 9.44.
UV-vis absorption (CH3CN): 573 nm (50000).
3
(t, | JFF| ) 21 Hz, 1F), -162.31 (m, 2F) ppm. FAB MS (NBA): m/z
) 303 [M + H]+, 302 [M]+. C13H7F5N2O (302.20): calcd C 51.67 H
2.33 N 9.27; found C 51.59 H 2.39 N 9.30. UV-vis absorption (CH3-
CN): 317 nm (12000).
2,4-Dimethoxyphenylazopentafluorobenzene, 8c. Yield ) 57%.
1H NMR (400 MHz, acetone-d6): δ ) 3.94 (s, 3H, CH3), 4.01 (s, 3H,
CH3), 6.64 (dd, 3JHH ) 9.1 Hz, 4JH-H ) 2.5 Hz, 1H, H5 phenyl), 6.79
4
3
(d, JHH ) 2.5 Hz, 1H, H3 phenyl), 7.69 (d, JHH ) 9.2 Hz, 1H, H6
phenyl) ppm. 13C NMR (100 MHz, acetone-d6): δ ) 56.32 (s, CH3),
56.76 (s, CH3), 99.66 (s, C3 phenyl), 107.75 (s, C5 phenyl), 118.17 (s,
C6 phenyl), 138.12 (s, C1 phenyl), 161.44 (s, C4 phenyl), 167.08 (s,
C2 phenyl) ppm. 19F NMR (282 MHz, acetone-d6): -153.32 (m, 2F),
4-Methoxyphenylazopentakis[4-(dimethylamino)-1-pyridinio]-
1
benzene Pentakis(triflate), 9b. Yield ) 97%. H NMR (400 MHz,
CD3NO2): δ ) 3.28 (s, 6H, CH3), 3.29 (s, 12H, CH3), 3.34 (s, 12H,
3
CH3), 3.91 (s, 3H, OCH3), 6.99 (d, JHH ) 9.3 Hz, 2H, H3/5 phenyl),
3
3
3
-157.62 (t, | JFF| ) 21 Hz, 1F), -164.92 (m, 2F) ppm. FAB MS
7.01 (d, JHH ) 7.9 Hz, 2H, H3/5 p-DMAP), 7.02 (d, JHH ) 8.1 Hz,
(NBA): m/z ) 333 [M + H]+, 332 [M]+. C14H9F5N2O2 (332.23): calcd
C 50.61 H 2.73 N 8.43; found C 50.68 H 2.80 N 8.40. UV-vis
absorption (CH3CN): 358 nm (11500).
4H, H3/5 DMAP), 7.06 (d, 3JHH ) 8.1 Hz, 4H, H3/5 DMAP), 7.50 (d,
3JHH ) 9.2 Hz, 2H, H2/6 phenyl), 8.26 (d, JHH ) 8.1 Hz, 2H, H2/6
3
p-DMAP), 8.31 (d, 3JHH ) 7.9 Hz, 4H, H2/6 DMAP), 8.33 (d, 3JHH
)
7.9 Hz, 4H, H2/6 DMAP) ppm. 13C NMR (100 MHz, CD3NO2): δ )
41.31 (s, CH3), 41.42 (s, CH3), 57.12 (s, OCH3), 109.36 (s, C3/5
DMAP), 110.53 (s, C3/5 DMAP), 110.63 (s, C3/5 p-DMAP), 116.52
1
4-Hydroxyphenylazopentafluorobenzene, 8d. Yield ) 44%. H
3
NMR (400 MHz, acetone-d6): δ ) 7.04 (d, JHH ) 8.9 Hz, 2H, H3/5
3
phenyl), 7.86 (d, JHH ) 8.9 Hz, 2H, H2/6 phenyl), 9.64 (s, 1H, OH)
1
ppm. 13C NMR (100 MHz, acetone-d6): δ ) 116.95 (s, C3/5 phenyl),
126.50 (s, C2/6 phenyl), 147.69 (s, C1 phenyl), 163.44 (s, C4 phenyl)
ppm. 19F NMR (282 MHz, acetone-d6): -152.84 (m, 2F), -156.78 (t,
(s, C3/5 phenyl), 122.11 (q, | JCF| ) 320 Hz, CF3), 128.34 (s, C2/6
phenyl), 136.07 (s, C2/3/5/6 onio-phenyl), 136.81 (s, C4 onio-phenyl),
140.40 (s, C2/3/5/6 onio-phenyl), 141.73 (s, C2/6 DMAP), 141.77 (s,
C2/6 p-DMAP), 143.22 (s, C2/6 DMAP), 148.66 (s, C1 phenyl/onio-
phenyl), 148.95 (s, C1 phenyl/onio-phenyl), 157.71 (s, C4 p-DMAP),
157.75 (s, C4 DMAP), 158.09 (s, C4 DMAP), 167.99 (s, C4 phenyl)
ppm. FAB MS (NBA): m/z ) 1413 [M - OTf]+, 1265 [M + H -
2OTf]+, 1116 [M + H - 3OTf]+. C53H57F15N12O16S5 (1563.38): calcd
C 40.72 H 3.67 N 10.75 S 10.25; found C 40.41 H 3.74 N 10.59 S
10.03. UV-vis absorption (CH3CN): 419 nm (28000).
3
| JFF| ) 21 Hz, 1F), -164.73 (m, 2F) ppm. FAB MS (NBA): m/z )
289 [M + H]+, 288 [M]+. C12H5F5N2O (288.18) + 0.5 H2O: calcd C
48.50 H 2.03 N 9.43; found C 48.87 H 2.34 N 9.31. UV-vis absorption
(CH3CN): 327 nm (14000).
2,4-Dihydroxyphenylazopentafluorobenzene, 8e. Yield ) 72%. 1H
NMR (400 MHz, acetone-d6): δ ) 6.42 (dd, 4JHH ) 2.5 Hz, J ) 2 Hz,
3
4
1H, H3 phenyl), 6.67 (dd, JHH ) 8.9 Hz, JH-H ) 2.5 Hz, 1H, H5
3
phenyl), 7.75 (d, JHH ) 8.9 Hz, J ) 2 Hz, 1H, H6 phenyl), 10.04 (s,
2,4-Dimethoxyphenylazopentakis[4-(dimethylamino)-1-pyridinio]-
1
1H, p-OH), 12.33 (s, 1H, o-OH) ppm. 13C NMR (100 MHz, acetone-
d6): δ ) 103.85 (s, C3 phenyl), 103.90 (s, C3 phenyl), 110.96 (s, C5
phenyl), 134.92 (s, C1 phenyl), 134.99 (s, C1 phenyl), 135.78 (s, C6
phenyl), 135.87 (s, C6 phenyl), 156.72 (s, C2 phenyl), 157.12 (s, C2
phenyl), 165.79 (s, C4 phenyl) ppm. 19F NMR (282 MHz, acetone-d6):
-152.43 (m, 2F), -156.72 (m, 1F), -164.52 (m, 2F) ppm. FAB MS
(NBA): m/z ) 305 [M + H]+, 304 [M]+. C12H5F5N2O2 (304.18) +
0.5 H2O: calcd C 46.02 H 1.93 N 8.94; found C 46.33 H 2.29 N 8.78.
UV-vis absorption (CH3CN): 389 nm (12500).
benzene Pentakis(triflate), 9c. Yield ) 98%. H NMR (400 MHz,
CD3NO2): δ ) 3.28 (s, 6H, CH3), 3.28 (s, 12H, CH3), 3.34 (s, 12H,
3
CH3), 3.86 (s, 3H, OCH3), 3.93 (s, 3H, OCH3), 6.47 (dd, JHH ) 9.6
Hz, 4JH-H ) 2.5 Hz, 1H, H5 phenyl), 6.59 (d, 4JHH ) 2.8 Hz, 1H, H3
phenyl), 6.98 (d, 3JHH ) 7.7 Hz, 2H, H3/5 p-DMAP), 7.00 (d, 3JHH
)
7.7 Hz, 4H, H3/5 DMAP), 7.04 (d, 3JHH ) 7.7 Hz, 4H, H3/5 DMAP),
3
3
7.29 (d, JHH ) 9.4 Hz, 1H, H6 phenyl), 8.27 (d, JHH ) 8.2 Hz, 4H,
3
H2/6 DMAP), 8.30 (d, JHH ) 8.3 Hz, 2H, H2/6 p-DMAP), 8.32 (d,
3JHH ) 8.3 Hz, 4H, H2/6 DMAP) ppm. 13C NMR (100 MHz, CD3-
9
J. AM. CHEM. SOC. VOL. 129, NO. 3, 2007 551

A R T I C L E S
Weiss and Pu¨hlhofer
NO2): δ ) 41.25 (s, CH3), 41.42 (s, CH3), 56.79 (s, OCH3), 57.32 (s,
OCH3), 99.28 (s, C3 phenyl), 109.42 (s, C3/5 DMAP), 110.10 (s, C5
phenyl), 110.46 (s, C3/5 DMAP), 110.54 (s, C3/5 p-DMAP), 119.84
(s, C6 phenyl), 122.16 (q, | JCF| ) 320 Hz, CF3), 135.78 (s, C4 onio-
CF3), 127.46 (s), 130.34 (s), 130.59 (s), 130.94 (s), 131.04 (s), 132.25
(s), 140.63 (s), 141.88 (s, C2/6 DMAP), 142.36 (s), 142.57 (s, C2/6
p-DMAP), 143.05 (s, C2/6 DMAP), 143.85 (s), 157.71 (s, C4 DMAP),
158.31 (s, C4 DMAP) ppm. FAB MS (NBA): m/z ) 1449 [M - OTf]+,
1299 [M - 2OTf]+, 1144 [M + H - NC10H6OH - 2OTf]+.
C56H57F15N12O16S5 (1599.42) + 3 H2O: calcd C 40.68 H 3.84 N 10.17
S 9.69; found C 41.42 H 3.86 N 10.27 S 9.10. UV-vis absorption
(CH3CN): 545 nm (22500).
1
phenyl), 135.88 (s, C2/3/5/6 onio-phenyl), 139.36 (s, C1 phenyl), 140.24
(s, C2/3/5/6 onio-phenyl), 141.85 (s, C2/6 DMAP), 142.00 (s, C2/6
p-DMAP), 143.22 (s, C2/6 DMAP), 148.93 (s, C1 onio-phenyl), 157.75
(s, C4 DMAP), 158.20 (s, C4 DMAP), 164.20 (s, C4 phenyl), 170.99
(s, C2 phenyl) ppm. FAB MS (NBA): m/z ) 1443 [M - OTf]+, 1294
[M - 2OTf]+, 1144 [M + H - NC6H4(OCH3)2 - 2OTf]+.
C54H59F15N12O17S5 (1593.41): calcd C 40.70 H 3.73 N 10.55 S 10.06;
found C 40.60 H 4.00 N 10.61 S 10.00. UV-vis absorption (CH3CN):
429 nm (20000).
4-Dimethylaminophenylazopentakis[4-(dimethylamino)-1-pyridinio]-
1
benzene Pentakis(iodide), 10. Yield ) quant. H NMR (400 MHz,
D2O/CF3COOD, low concentration f low resolution): δ ) 2.09 (s,
CH3), 2.10 (s, CH3), 2.11 (s, CH3), 2.13 (s, CH3), 5.80 (d, 6H, H3/5
3
DMAP), 5.82 (d, 4H, H3/5 DMAP), 5.95 (d, JHH ) 9.5 Hz, 2H,
3
3
phenyl), 6.24 (d, JHH ) 9.3 Hz, 2H, phenyl), 6.98 (d, JHH ) 8.0 Hz,
4-Hydroxyphenylazopentakis[4-(dimethylamino)-1-pyridinio]-
4H, H2/6 DMAP), 7.24 (d, 3JHH ) 7.8 Hz, 6H, H2/6 DMAP) ppm. 13
C
1
benzene Pentakis(triflate), 9d. Yield ) 95%. H NMR (400 MHz,
NMR (concentration too low). FAB MS (NBA): m/z ) 1338 [M -
I]+, 1211 [M - 2I]+, 1084 [M - 3I]+. C49H60I5N13 (1465.63) + 3
H2O: calcd C 38.73 H 4.38 N 11.98; found C 38.82 H 4.31 N 11.89.
UV-vis absorption (CH3CN): 574 nm (60000).
CD3NO2): δ ) 3.28 (s, 6H, CH3), 3.29 (s, 12H, CH3), 3.33 (s, 12H,
3
3
CH3), 6.90 (d, JHH ) 9.1 Hz, 2H, H3/ 5 phenyl), 7.00 (d, JHH ) 7.7
3
Hz, 2H, H3/5 p-DMAP), 7.01 (d, JHH ) 8.0 Hz, 4H, H3/5 DMAP),
7.04 (d, 3JHH ) 8.0 Hz, 4H, H3/5 DMAP), 7.43 (d, 3JHH ) 9.1 Hz, 2H,
H2/6 phenyl), 8.29 (d, 3JHH ) 7.7 Hz, 6H, H2/6 DMAP), 8.34 (d, 3JHH
) 8.0 Hz, 4H, H2/6 DMAP) ppm. 13C NMR (100 MHz, CD3NO2): δ
) 41.30 (s, CH3), 41.43 (s, CH3), 109.34 (s, C3/5 DMAP), 110.49 (s,
C3/5 DMAP), 110.58 (s, C3/5 p-DMAP), 118.13 (s, C3/5 phenyl),
4-(4-Dimethylaminophenylazo)tetrakis[4-(dimethylamino)-1-py-
ridinio]phenolate Tris(triflate), 11. Yield ) 74%. 1H NMR (400 MHz,
CD3CN): δ ) 3.00 (s, 6H, CH3), 3.28 (s, 12H, CH3), 3.33 (s, 12H,
3
3
CH3), 6.57 (d, JHH ) 9.3 Hz, 2H, H3/5 phenyl), 6.96 (d, JHH ) 7.7
1
3
122.08 (q, | JCF| ) 319 Hz, CF3), 128.75 (s, C2/ 6 phenyl), 136.02 (s,
Hz, 4H, H3/5 DMAP), 6.99 (d, JHH ) 7.7 Hz, 4H, H3/5 DMAP),
7.01 (d, 3JHH ) 9.2 Hz, 2H, H2/6 phenyl), 8.06 (d, 3JHH ) 7.7 Hz, 4H,
C2/3/5/6 onio-phenyl), 136.49 (s, C4 onio-phenyl), 140.35 (s, C2/3/
5/6 onio-phenyl), 141.79 (s, C2/6 DMAP), 141.87 (s, C2/6 p-DMAP),
143.25 (s, C2/6 DMAP), 148.64 (s, C1 phenyl/onio-phenyl), 148.83
(s, C1 phenyl/ onio-phenyl), 157.71 (s, C4 p-DMAP), 157.74 (s, C4
DMAP), 158.09 (s, C4 DMAP), 166.59 (s, C4 phenyl) ppm. FAB MS
(NBA): m/z ) 1399 [M - OTf]+, 1250 [M - 2OTf]+, 1144 [M + H
- NC6H4OH - 2OTf]+. C52H55F15N12O16S5 (1549.36) + 4 H2O: calcd
C 38.52 H 3.92 N 10.37 S 9.89; found C 38.61 H 3.83 N 9.95 S 9.71.
UV-vis absorption: 413 nm (22500) (CH3CN); 535 (26500) (CH3CN
+ excess DMAP).
H2/6 DMAP), 8.18 (d, JHH ) 7.8 Hz, 4H, H2/6 DMAP) ppm. 13C
3
NMR (100 MHz, CD3CN): δ ) 40.86 (s, CH3), 41.00 (s, CH3), 108.63
(s, C3/5 DMAP), 108.89 (s, C3/5 DMAP), 112.72 (s, C3/5 phenyl),
1
122.39 (q, | JCF| ) 320 Hz, CF3), 125.39 (s, C2/6 phenyl), 125.68 (s,
C1/4 phenyl/C1 onio-phenyl), 132.67 (s, C2/3/5/6 onio-phenyl), 135.94
(s,C2/3/5/6 onio-phenyl), 144.35 (s, C2/6 DMAP), 144.66 (s, C2/6
DMAP), 144.87 (s, C1/4 phenyl/C1 onio-phenyl), 154.09 (s, C1/4
phenyl/C1 onio-phenyl), 157.85 (s, C4 DMAP), 158.12 (s, C4 DMAP),
164.11 (s, C4 onio-phenyl) ppm. FAB MS (NBA): m/z ) 1022 [M -
OTf]+, 872 [M - HOTf - OTf]+. C45H50F9N11O10S3 (1172.13) + 3
H2O: calcd C 44.08 H 4.60 N 12.57 S 7.84; found C 43.92 H 4.37 N
12.37 S 7.68. UV-vis absorption (CH3CN): 503 nm (35000).
Pentafluorobenzaldehyde 4-Dimethylaminophenylimine, 12. Yield
) 65%. 1H NMR (400 MHz, CDCl3): δ ) 3.07 (s, 6H, CH3), 6.73 (d,
2,4-Dihydroxyphenylazopentakis[4-(dimethylamino)-1-pyridinio]-
1
benzene Pentakis(triflate), 9e. Yield ) quant. H NMR (400 MHz,
CD3NO2): δ ) 3.26 (s, 6H, CH3), 3.27 (s, 12H, CH3), 3.32 (s, 12H,
CH3), 6.13 (sb, 1H, H3 phenyl), 6.48 (d, 3JHH ) 9.4 Hz, 1H, H5 phenyl),
6.96 (d, 3JHH ) 7.7 Hz, 2H, H3/5 p-DMAP), 6.97 (mb, 1H, H6 phenyl),
6.98 (d, 3JHH ) 8.0 Hz, 4H, H3/5 DMAP), 7.04 (d, 3JHH ) 8.3 Hz, 4H,
3
3JHH ) 9.1 Hz, 2H, H3/5 phenyl), 7.79 (d, JHH ) 9.1 Hz, 2H, H2/6
3
phenyl), 8.35 (s, 1H, -CH)N-) ppm. 13C NMR (100 MHz, CDCl3): δ
) 40.25 (s, CH3), 111.67 (s, C3/5 phenyl), 123.14 (s, C1 phenyl), 131.48
(s, C2/6 phenyl), 153.38 (s, C4 phenyl), 167.57 (s, CHdN) ppm. 19F
NMR (282 MHz, CDCl3): -161.71 (m, 2F), -164.37 (m, 2F), -172.68
(m, 1F) ppm. FAB MS (NBA): m/z ) 314 [M]+. C15H11F5N2
(314.26): calcd C 57.33 H 3.53 N 8.91; found C 57.22 H 3.51 N 8.77.
UV-vis absorption (CH3CN): 363 nm (37000).
H3/5 DMAP), 8.28 (d, JHH ) 8.0 Hz, 2H, H2/6 p-DMAP), 8.32 (d,
3
3JHH ) 8.0 Hz, 4H, H2/6 DMAP), 8.34 (d, JHH ) 7.7 Hz, 4H, H2/6
DMAP), 12.17 (sb, OH) ppm. 13C NMR (100 MHz, CD3NO2): δ )
41.29 (s, CH3), 41.38 (s, CH3), 104.55 (s, C5 phenyl), 109.73 (s, C3/5
DMAP), 110.36 (s, C3/5 DMAP), 110.45 (s, C3/5 p-DMAP), 116.11
1
(sb, C3 phenyl), 122.10 (q, | JCF| ) 319 Hz, CF3), 134.85 (s, C6 phenyl),
137.36 (s), 140.51 (s), 141.55 (s), 141.88 (s, C2/6 DMAP), 142.32 (s,
C2/6 p-DMAP), 142.53 (s), 143.23 (s, C2/6 DMAP), 149.15 (s, C1
onio-phenyl), 157.74 (s, C4 DMAP), 158.06 (s, C4 DMAP) ppm. FAB
MS (NBA): m/z ) 1415 [M - OTf]+, 1266 [M - 2OTf]+, 1144 [M
+ H - NC6H3(OH)2 - 2OTf]+. C52H55F15N12O17S5 (1565.35) + H2O:
calcd C 39.45 H 3.63 N 10.62 S 10.12; found C 39.38 H 3.64 N 10.49
S 10.19. UV-vis absorption (CH3CN): 477 nm (30500).
Pentakis[4-(dimethylamino)-1-pyridinio]benzaldehyde 4-Dimeth-
1
ylaminophenylimine Pentakis(triflate), 15. Yield ) 85%. H NMR
(400 MHz, CD3NO2): δ ) 3.07 (s, 6H, CH3), 3.22 (s, 12H, CH3),
3
3.26 (s, 6H, CH3), 3.26 (s, 12H, CH3), 6.66 (d, JHH ) 9.2 Hz, 2H,
3
H2/3/5/6 phenyl), 6.96 (d, JHH ) 8.3 Hz, 2H, H3/5 p-DMAP), 6.97
3
3
(d, JHH ) 7.9 Hz, 4H, H3/5 DMAP), 6.98 (d, JHH ) 8.2 Hz, 4H,
3
2-Hydroxynaphthylazopentakis[4-(dimethylamino)-1-pyridinio]-
H3/5 DMAP), 7.48 (d, JHH ) 9.2 Hz, 2H, H2/3/5/6 phenyl), 8.23 (s,
1
benzene Pentakis(triflate), 9f. Yield ) 97%. H NMR (400 MHz,
1H, -NdCH-), 8.30 (m, 10H, H2/6 DMAP) ppm. 13C NMR (100 MHz,
CD3NO2): δ ) 40.32 (s, CH3), 41.17 (s, CH3), 41.35 (s, CH3), 109.72
(s, C3/5 DMAP), 110.35 (s, C3/5 DMAP), 110.39 (s, C3/5 p-DMAP),
CD3NO2): δ ) 3.25 (s, 6H, CH3), 3.27 (s, 12H, CH3), 3.31 (s, 12H,
3
3
CH3), 6.42 (d, JHH ) 9.4 Hz, 1H, naphthyl), 6.92 (d, JHH ) 8.2 Hz,
3
1
1H, naphthyl), 6.95 (d, JHH ) 8.2 Hz, 2H, H3/5 p-DMAP), 6.98 (d,
112.49 (s, C3/5 phenyl), 122.18 (q, | JCF| ) 320 Hz, CF3), 122.75 (s,
3JHH ) 8.1 Hz, 4H, H3/5 DMAP), 7.08 (d, JHH ) 7.7 Hz, 4H, H3/5
C1/4 (onio-)phenyl), 131.61 (s, C1/4 (onio-)phenyl), 133.65 (s, C2/6
phenyl), 134.39 (s, C2/3/5/6 onio-phenyl), 139.29 (s, C2/3/5/6 onio-
phenyl), 141.86 (s, C2/6 DMAP), 142.49 (s, C2/6 p-DMAP), 142.92
(s, C2/6 DMAP), 154.32 (s, C1/4 (onio-)phenyl), 156.10 (s, C1/4 (onio-
)phenyl), 157.73 (s, C4 p-DMAP), 157.76 (s, C4 DMAP), 157.96 (s,
C4 DMAP), 168.87 (s, -NdCH-) ppm. FAB MS (NBA): m/z ) 1425
[M - OTf]+, 1275 [M - HOTf-OTf]+, 1155 [M-C6H4N(CH3)2-DMAP
- 2OTf]+, 1021 [M-CHC6H4N(CH3)2-DMAP - 2OTf]+. C55H61F15-
3
DMAP), 7.30 (m, 1H, naphthyl), 7.53 (d, 3JHH ) 7.2 Hz, 1H, naphthyl),
3
7.68 (m, 1H, naphthyl), 8.05 (d, JHH ) 7.8 Hz, 1H, naphthyl), 8.27
3
3
(d, JHH ) 7.9 Hz, 2H, H2/6 p-DMAP), 8.32 (d, JHH ) 7.9 Hz, 4H,
H2/6 DMAP), 8.37 (d, JHH ) 7.7 Hz, 4H, H2/6 DMAP) ppm. 13C
3
NMR (100 MHz, CD3NO2): δ ) 41.30 (s, CH3), 41.35 (s, CH3), 110.06
(s, naphthyl), 109.32 (s, C3/5 DMAP), 110.39 (s, C3/5 DMAP), 110.46
1
(s, C3/5 DMAP), 111.12 (s, naphthyl), 122.16 (q, | JCF| ) 320 Hz,
9
552 J. AM. CHEM. SOC. VOL. 129, NO. 3, 2007

Electrostatics and Color
A R T I C L E S
3
N12O15S5 (1575.44) + 2 H2O: calcd C 40.99 H 4.07 N 10.43 S 9.95;
found C 40.82 H 3.96 N 10.44 S 9.88. UV-vis absorption (CH3CN):
415 nm (29000).
CH3), 3.31 (s, 12H, CH3), 6.28 (d, JH ) 16.6 Hz, 1H, -CHdCH-),
3
3
6.60 (d, JHH ) 9.0 Hz, 2H, H2/3/5/6 phenyl), 6.52 (d, JHH ) 16.5
Hz, 1H, -CHdCH-), 6.96 (d, 3JHH ) 6.6 Hz, 2H, H3/5 p-DMAP), 6.98
3
3
4-Dimethylaminobenzaldehyde Pentakis[4-(dimethylamino)-1-
pyridinio]phenylimine Pentakis(triflate), 16. Yield ) quant. 1H NMR
(400 MHz, CD3NO2): δ ) 3.00 (s, 6H, CH3), 3.27 (s, 6H, CH3), 3.28
(s, 12H, CH3), 3.37 (s, 12H, CH3), 6.61 (d, 3JH-H ) 9.4 Hz, 2H, H2/
(d, JHH ) 7.9 Hz, 4H, H3/5 DMAP), 7.08 (d, JHH ) 8.1 Hz, 4H,
3
H3/5 DMAP), 7.11 (d, JHH ) 8.9 Hz, 2H, H2/3/5/6 phenyl), 8.23 (d,
3JHH ) 8.1 Hz, 2H, H2/6 p-DMAP), 8.26 (d, 3JHH ) 7.9 Hz, 4H, H2/6
DMAP), 8.32 (d, JHH ) 7.9 Hz, 4H, H2/6 DMAP) ppm. 13C NMR
3
3
3/5/6 phenyl), 6.91 (d, JHH ) 9.4 Hz, 2H, H2/3/5/6 phenyl), 6.97 (d,
(100 MHz, CD3NO2): δ ) 40.29 (s, CH3), 41.31 (s, CH3), 41.38 (s,
CH3), 109.63 (s, -CHdCH-), 110.17 (s, C3/5 DMAP), 110.43 (s, C3/5
DMAP), 110.46 (s, C3/5 p-DMAP), 112.97 (s, C3/5 phenyl), 122.17
(q, | JCF| ) 321 Hz, CF3), 123.58 (s, C1/4 (onio-)phenyl), 130.56 (s,
3JHH ) 7.7 Hz, 2H, H3/5 p-DMAP), 6.99 (d, 3JHH ) 7.7 Hz, 4H, H3/5
DMAP), 7.11 (d, 3JHH ) 7.7 Hz, 4H, H3/5 DMAP), 8.12 (s, 1H, -CHd
3
3
N-), 8.27 (d, JHH ) 8.2 Hz, 2H, H2/6 p-DMAP), 8.31 (d, JHH ) 7.7
Hz, 4H, H2/6 DMAP), 8.37 (d, 3JHH ) 7.7 Hz, 4H, H2/6 DMAP) ppm.
13C NMR (100 MHz, CD3NO2): δ ) 40.46 (s, CH3), 41.35 (s, CH3),
1
C2/6 phenyl), 135.34 (s, C1/4 (onio-)phenyl), 139.50 (s, C/3/5/6 onio-
phenyl), 140.55 (s, C2/3/5/6 onio-phenyl), 141.78 (s, C2/6 DMAP),
142.02 (s,C2/6 p-DMAP), 142.78 (s,C2/6 DMAP), 144.04 (s, C1/4
(onio-)phenyl), 144.58 (s, -CHdCH-), 153.62 (s, C1/4 (onio-)phenyl),
157.71 (s, C4 DMAP), 158.00 (s, C4 DMAP) ppm. FAB MS (NBA):
m/z ) 1424 [M - OTf]+, 1274 [M - HOTf - OTf]+, 1154 [M -
C6H4N(CH3)2 - HOTf - OTf]+, 1020 [M - CHC6H4N(CH3)2 - DMAP
- 2OTf]+. C56H62F15N11O15S5 (1574.45) + 2 H2O: calcd C 41.76 H
4.13 N 9.57 S 9.95; found C 41.58 H 3.97 N 9.21 S 10.00. UV-vis
absorption (CH3CN): 470 nm (24000).
41.41 (s, CH3), 109.89 (s, C3/ 5 DMAP), 110.43 (s, C3/5 DMAP),
1
110.52 (s, C3/5 p-DMAP), 113.13 (s, C3/5 phenyl), 122.17 (q, | JCF
|
) 320 Hz, CF3), 125.60 (s, C2/6 phenyl), 137.04 (s, C1/4 (onio-)-
phenyl), 137.98 (s, C1/4 (onio-)phenyl), 138.95 (s, C1/4 (onio-)phenyl),
140.14 (s, -CHdN-), 140.47 (s, C2/3/5/6 onio-phenyl), 141.15 (s, C2/
3/5/6 onio-phenyl), 141.88 (s, C2/6 DMAP), 143.17 (s, C2/6 DMAP),
153.72 (s, C1/4 (onio-)phenyl), 157.75 (s, C4 DMAP), 158.26 (s, C4
DMAP) ppm. FAB MS (NBA): m/z ) 1425 [M - OTf]+, 1155 [M -
C6H4N(CH3)2
DMAP - 2OTf]+, 1021 [M -CHC6H4N(CH3)2
-
-
DMAP - 2OTf]+. C55H61F15N12O15S5 (1575.44) + H2O: calcd C 41.46
H 3.99 N 10.55 S 10.06; found C 41.29 H 3.75 N 10.49 S 9.89. UV-
vis absorption (CH3CN): 534 nm (28000).
Acknowledgment. Support of this research by the Deutsche
Forschungsgemeinschaft (grants WE 599/ 9-1 and 599/9-2) is
gratefully acknowledged.
Pentakis[4-(dimethylamino)-1-pyridinio]-4-dimethylaminophen-
1
ylstilbene Pentakis(triflate), 17. Yield ) 92%. H NMR (400 MHz,
CD3NO2): δ ) 2.98 (s, 6H, CH3), 3.26 (s, 6H, CH3), 3.27 (s, 12H,
JA064907U
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J. AM. CHEM. SOC. VOL. 129, NO. 3, 2007 553