The synthesis of new phthalocyanines substituted with 12-membered diazadioxa macrocycles

Article abstract of DOI:10.1007/s007060270007

A macrocyclic diazadioxa dibromo compound was synthesized by ring closure of 1,2-bis-(2-iodoethoxy)-4,5-dibromo-benzene and 1,4-bis-(p-tolylsulfonyl)-ethylenediamine. Its phthalonitrile derivative was obtained by cyano substitution. This diazadioxa macroc

Full text of DOI:10.1007/s007060270007

Monatshefte fuÈr Chemie 133, 71±78 (2002)
The Synthesis of New Phthalocyanines
Substituted with 12-Membered
Diazadioxa Macrocycles
Ã
È
Tanju Ceyhan and Ozer Bekaroglu
Æ
_
Technical Universityof Istanbul, Department of Chemistry, TR-80626 Maslak, Istanbul, Turkey
_
Summary. A macrocyclic diazadioxa dibromo compound was synthesized by ring closure of
1,2-bis-(2-iodoethoxy)-4,5-dibromo-benzene and 1,4-bis-(p-tolylsulfonyl)-ethylenediamine. Its
phthalonitrile derivative was obtained bycyano substitution. This diazadioxa macrocyclic dibromo
derivative was directlyconverted into the copper(II) phthalocyanine byreaction with CuCN in tetra-
methyl urea. Conversion of this phthalonitrile derivative into the metal-free phthalocyanine was ac-
complished byre¯uxing with DBU. The zinc(II) phthalocyanine was prepared by reaction of the
dinitrile derivative with Zn(OAc)2 in quinoline. The lutetium bis-(phthalocyaninate) complex
was obtained bytreating the dinitrile derivative with anhydrous lutetium acetate and DBU in 1-
hexanol. The new compounds were characterized byelemental analyses and IR, 1H NMR, mass, UV/
Vis, and ESR spectra.
Keywords. Diazadioxa macrocycle; Phthalonitrile; Phthalocyanine; Cyclotetramerization.
Introduction
In addition to their industrial importance as pigments, metal phthalocyanines
have been extensivelystudied because of their interesting conductivity, catalytic,
photovoltaic, andelectrochromicproperties[1].Thephysicalandchemicalproperties
of soluble phthalocyanines (Pc) have recentlyattracted attention from materials
chemists for their potential use in semiconducting materials, nonlinear optics, and
other optical devices [2].
The growing use of phthalocyanines as advanced materials during the last
decade has encouraged research on the synthesis of new derivatized materials
which differ in the central metal ion or in the peripheral substituents. Despite this
extensive interest, there are relatively few synthetic routes to phthalocyanine
derivatives, covering mainlyphthalonitrile derivatives and aromatic ortho-dibromo
compounds [3]. For this reason, attention has been focused on their synthesis with
new substituents.
We have previously synthesized phthalocyanines substituted with oxa and /or
aza macrocycles, which are very soluble in common organic solvents and capable
Ã
Corresponding author. E-mail: obek@itu.edu.tr


ꢀ
T. Ceyhan and O. Bekaroglu
72
of binding alkali metal ions [4±6]. Phthalocyanines substituted with 14- or 15-
membered tetraaza macrocycles provided donor sites for coordinating to transition
metal ions [7, 8]. The phthalocyanines substituted with 17-membered diazatrioxa
macrocycles are soluble to a certain extent, but neither alkali nor transition metal
complexes could be isolated due to their low stability[9].
We describe here for the ®rst time the preparation of a 12-membered symmet-
rical diazadioxa macrocycle and metal phthalocyanines containing four 12-
membered diazadioxa macrocyclic units derived thereof.
Results and Discussion
The ®rst step in the synthetic procedure outlined in Scheme 1 is the formation of
the diazadioxa macrocycle 1. Starting from 1,4-bis-( p-tolylsulfonyl)-ethylenedi-
amine and 1,2-bis-(2-iodoethoxy)-4,5-dibromo-benzene, cyclization was accom-
plished in DMF in the presence of Cs2CO3 as the base [7, 8]. The relativelyhigh
yield of this reaction between two bifunctional reactants indicated the template
effect of the cesium ion [10]. Tosyl groups are not only effective in cyclization,
but also used as protective groups for the aza functions in the cyclotetrameriza-
tion to form the phthalocyanine. The dicyano derivative 2 was prepared bythe
Rosenmund-von Braun reaction, which might be considered as an intermediate step
in the phthalocyanine formation. This conversion was achieved by treatment with
cuprous cyanide in DMF at low concentrations to avoid the formation of phthalo-
cyanine [11].
The diazadioxa macrocycle 1 was directlyconverted into the copper(II)
phthalocyanine 5 by reaction with CuCN in tetramethyl urea. The usual synthetic
routes were applied to obtain the metal-free and the divalent metal phthalocya-
nines. Conversion of 2 into the metal-free phthalocyanine 3 was accomplished
directlybyre¯uxing 3 in DBU. The reaction of 2 in a high-boiling solvent, such as
quinoline, with zinc(II) acetate gave the divalent metal phthalocyanine 4. The most
characteristic feature of complexes 3±5 is their high solubilityin common organic
solvents like chloroform, dichloromethane, THF, DMF, and DMSO.
The reaction of 2 with anhydrous lutetium acetate and DBU in 1-hexanol gave
the lutetium bis-(phthalocyaninate) complex 6 (Fig. 1) in 57% yield. Compound 6
is soluble in common organic solvents such as chloroform, dichloromethane, THF,
DMF, and DMSO. All new compounds and phthalocyanines were suf®ciently pure
and gave satisfactoryanalytical results.
The spectroscopic data of the newlysynthesized intermediates and phthalo-
cyanines were in accordance with the proposed structures. Comparison of the IR
spectra gave some hints to the nature of the products. In this context, we maycite
the presence of SO2 vibrations in the spectra of 1±6 at 1340 and 1140 cmÀ1. The
intense absorption band of 2 at 2213 cmÀ1, corresponding to the CꢀN groups,
disappeared after its conversion into the phthalocyanines 3±6. The band around
3300 cmÀ1 for 3 can be attributed to the NH stretching frequencyof the inner core
of the metal-free phthalocyanine. The 1H NMR spectra are also consistent with the
proposed structures. The aromatic protons of 1 appeared at 7.24±7.68 ppm, the
CH2O and CH2N protons at 3.91±4.23 and 3.31±3.37 ppm. The Ar-CH3 protons
were found at 2.41 ppm. The 1H NMR spectrum of 2 was similar to that of 1. The

Substituted Phthalocyanines
73
Scheme 1. i, Cs2CO3, DMF; ii, CuCN, tetramethyl urea; iii, CuCN, DMF; iv, DBU, 1-pentanol;
v, quinoline, anhydrous Zn(O2CMe)2
aromatic protons resonated at 7.44±7.85 ppm, the CH2O and CH2N protons at
4.28±4.37 and 3.31±3.38 ppm, and the Ar-CH3 protons at 2.41 ppm. The 1H NMR
spectrum of 3 was similar to that of 4 with the onlydifference that the NH protons
of 3 showed a peak at À4.3 ppm as a result of the 18-ꢀ electron system of the
phthalocyanine ring [4, 12]. 1H NMR measurements of 5 were precluded owing to
its paramagnetic nature.
Onlyfew NMR data concerning lutetium bis-(phthalocyaninates) are available
from the literature [13, 14], most of them dealing with the reduced forms [15, 16].
For all neutral forms, the paramagnetism of LuPc2 perturbs the signals of protons


ꢀ
T. Ceyhan and O. Bekaroglu
74
Fig. 1. Proposed structure for the lutetium bis-(phthalocyaninate) complex 6
located in the vicinityof the aromatic core. The good solubilityof the lutetium
complex 6 in chloroform enabled us to record its H NMR spectrum. The broad
1
signals which were observed in the aromatic region could be attributed to the
aromatic protons in the substituent. Whereas the OCH2 protons were found at
4.28±3.62 ppm, the NCH2 protons and tosyl CH3 protons resonated at 3.34±3.26
and 2.17 ppm, respectively. This interpretation is also consistent with the
integration values.
The phthalocyanines 3±5 displayed typical electronic spectra with two strong
absorption bands, one of them in the UV region at about 300±350 nm (B-band),
and the other one in the visible part at 600±700 nm (Q-band). The characteristic
Q-band transition of copper phthalocyanine with D4h symmetry is observed as a
single band of high intensityat 678 nm [6]. Gradual increases in the concentration
resulted in a lowering of the intensityof the Q-band at 678 nm together with a
slight increase in the absorbtion at 654 nm denoting the formation of aggregated
species [4]. The D2h symmetry of the metal-free phthalocyanine 3 is veri®ed bythe
two absorptions in the visible region at 678 and 647 nm.
The electronic spectrum of the zinc(II) phthalocyanine 4 contained a Q-band at
676 nm and a Soret band at 340 nm. Anyincrease in concentration resulted in the
aggregation of phthalocyanine molecules, which was accompanied by a shift of the
Q-band with some decrease in intensity. The UV/ Vis spectrum of the lutetium bis-
(phthalocyanine) 6 showed a Q-band at 677 nm, a Soret band at 343 nm, and a
typical radical phthalocyanine anion band as a shoulder in the 400±500 nm region
[17, 18, 19±22].
A close investigation of the mass spectra of 1±5 con®rmed the proposed
structures. FAB mass spectroscopyhas been extensivelyused to characterize various
sandwich complexes [13, 15, 23±26]. However, the spectra of lutetium sand-
wich complexes varydrasticallywith the matrix used [25, 26]. Thus, FAB-MS gave
onlyfragmentation peaks for the present compound.
The free radical nature of the green LuPc2 complex was con®rmed byits ESR
spectrum [27]. The spectrum of a solid sample of 6 at room temperature, which
shows a strong signal at g ˆ 2.007 with a bandwidth of 10 G, con®rmed the presence
of an unpaired spin and is consistent with the occurrence of a phthalocyanine
radical [28] (Fig. 2). Probably, both phthalocyanine ligands are symmetrically

Substituted Phthalocyanines
75
Fig. 2. X-Band ESR spectrum of the lutetium bis-(phthalocyaninate) complex 6
attached to the central metal atom. An intramolecular charge transfer with the
free electron hopping between the two phthalocyanine rings has been suggested
for the green form of LuPc2 [29, 30].
Experimental
IR spectra were recorded on a ATI Unicom-Mattson 1000 spectrophotometer using KBr pellets,
electronic spectra on a ATI Unicom UV/ Vis spectrometer UV2. Elemental analyses were performed
_
bythe instrumental analysis laboratoryof the TUB ITAK Marmara Research Centre. Their results
agreed favourablywith the calculated values. 1H NMR spectra: Bruker 200 MHz spectrometer; mass
spectra: VG Zabspec GS-MS spectrometer; ESR spectra: Bruker 380 EMX spectrometer operated at
X-band. 1,2-Bis-(2-iodoetoxy)-4,5-dibromo benzene [31] and 1,4-bis-(p-tolyl sulfonyl)-ethylenedi-
amine [32] were prepared according to reported procedures.
2,3-Dibromo-8,11-bis-(p-tolylsulfonyl)-6,7,8,9,10,11,12,13-octahydro-5,14-dioxa-8,11-diaza-
benzocyclododecene (1; C26H28O6N2S2Br2)
1,4-Bis-(p-tolylsulfonyl)-ethylenediamine (0.73 g, 2 mmol) was dissolved in 200 cm3 DMF contain-
ing 1.36 g ®nelyground anhydrous Cs 2CO3 (4.2 mmol) and stirred at room temperature for 15 min
under N2. A solution of 1.15 g 1,2-bis-(2-iodo-ethoxy)-4,5-dibromo-benzene (2 mmol) in 80 cm3
DMF was added dropwise over a period of 5 h. After stirring the reaction mixture for a further 24 h at
room temperature, 500 cm3 ice-water was added. The white solid which precipitated upon addition
of 60 drops of concentrated HCl was collected by®ltration and washed with H 2O to neutral. The wet
solid was dissolved in 30 cm3 CH2Cl2, and the solution was dried over Na2SO4. After the volume of
the ®ltrate was reduced to 10 cm3, 15 cm3 petroleum ether were added. Finally, the crystalline white
product was ®ltered and dried in vacuo.
Yield: 0.96 g (70%); m.p.: 179ꢁC; IR (KBr): ꢁ ˆ 3106 (CH aromatic), 2928±2850 (CH aliphatic),
1
1340, 1140 (Ar-CH3), 640 (C-Br) cmÀ1; H NMR (DMSO-d6, ꢂ, 200 MHz): 2.41 (s, 6H, Ar-CH3),


ꢀ
T. Ceyhan and O. Bekaroglu
76
3.34 (t, J ˆ 6.4 Hz, 8H, NCH2), 4.13 (t, J ˆ 6.2 Hz, 4H, OCH2), 7.46 (t, J ˆ 6.2 Hz, 10H, aromatic H)
‡
ppm; MS (EI): m /z ˆ 687 (M ).
8,11-Bis-(p-tolylsulfonyl)-6,7,8,9,10,11,12,13-octahydro-5,14-dioxa-8,11-diaza-
benzocyclododecene-2,3-dicarbonitrile (2; C28H28O6 N4S2)
Compound 1 (0.8 g, 1.16 mmol), 0.31 g CuCN (3.48 mmol), and 5 cm3 anhydrous DMF were
re¯uxed at 160ꢁC for 24 h under N2. After cooling to room temperature the dark brown mixture was
poured into 25 cm3 NH4OH (25%), and air was passed through the solution for 24 h. The creamy
coloured precipitate was ®ltered off, washed with H2O until the ®ltrate was neutral, and dried in
vacuo at 50ꢁC. This crude product was dissolved in CH2Cl2, ®ltered, and the ®ltrate was evaporated
to dryness. Recrystallization from EtOH gave a creamy coloured product. Compound 2 is soluble in
CHCl3, CH2Cl2, THF, DMF, and DMSO.
Yield: 0.27 g (40%); m.p.: 196ꢁC; IR (KBr): ꢁ ˆ 3100 (CH aromatic), 2928±2850 (CH aliphatic),
1
2213 (CꢀN), 1340 and 1140 (Ar-CH3) cmÀ1; H NMR (DMSO-d6, ꢂ, 200 MHz): 2.41 (s, 6H, Ar-
CH3), 3.34 (t, J ˆ 6.6 Hz, 8H, NCH2), 4.33 (t, J ˆ 6.4 Hz, 4H, OCH2), 7.44±7.85 (m, 10H, aromatic
‡
H) ppm; MS (EI): m /z ˆ 580 (M ).
4,7-Bis-(p-tolylsulfonyl)-2,3,5,6,8,9,17,18,20,21,23,24,31,32,34,35,37,38,46,47,49,50,52,53-
tetracosahydro-61H,63H-tetrakis-((4,7)-diaza-(1,10)-dioxa)-cyclodecine
[5,6-b:51,61-k:511,611-t:5 111,6111-c1]phthalocyanine (3; C112H114O24N16S8)
A mixture of 0.12 g 2 (0.2 mmol) and 0.03 cm3 DBU in 7 cm3 1-pentanol was re¯uxed under N2 for
5 h. After cooling to room temperature, 10 cm3 of EtOH were added. The dark-green precipitate was
®ltered, washed several times successivelywith hot H O, hot EtOH, hot MeOH, hot ethyl acetate,
2
and diethyl ether in order to remove the unreacted organic materials, and dried. Compound 3 is soluble
in CHCl3, CH2Cl2, THF, DMF, and DMSO.
Yield: 0.047 g (39%); IR (KBr): ꢁ ˆ 3300 (NH), 3100 (CH aromatic), 2928±2850 (CH aliphatic),
1340 and 1140 (Ar-CH3) cmÀ1; 1H NMR (DMSO-d6, ꢂ, 200 MHz): 7.27±6.67 (m, 40H, aromatic H),
4.23 (t, J ˆ 6.0 Hz, 16H, OCH2), 2.91 (t, J ˆ 6.2 Hz, 32H, NCH2), 2.22 (s, 24H, tosyl CH3), À4.3 (s,
‡
2H, NH) ppm; MS (FAB): m /z ˆ 2322 [M ].
4,7-Bis-(p-tolyl sulfonyl)-2,3,5,6,8,9,17,18,20,21,23,24,31,32,34,35,37,38,46,47,49,50,52,53-
tetracosahydro-61H,63H-tetrakis-((4,7)-diaza-(1,10)-dioxa)-cyclodecine
[5,6-b:51,61-k:511,611-t:5111,6111-c1]phthalocyaninato zinc(II) (4; C112H112O24N16S8Zn)
A mixture of 0.120 g 2 (0.2 mmol), 0.01 g, anhydrous zinc acetate (0.05 mmol), and 0.5 cm3
quinoline was heated and stirred at 180±190ꢁC for 20 h under N2. After cooling to room temperature,
the dark-green mixture was diluted with 5 cm3 EtOH and ®ltered. The product was washed with
2 Â 20 cm3 hot H2O, 3 Â 20 cm3 EtOH, 2 Â 20 cm3 MeOH, and 2 Â 20 cm3 ethyl acetate and dried.
Compound 4 is soluble in CHCl3, CH2Cl2, DMF pyridine, and DMSO.
Yield: 0.052 g (43%); IR (KBR): ꢁ ˆ 3106 (CH aromatic), 2928±2850 (CH aliphatic), 1340 and
1
1140 (Ar-CH3) cmÀ1; H NMR (DMSO-d6, ꢂ, 200 MHz): 7.68±6.77 (m, 40H, aromatic H), 4.43 (t,
J ˆ 6.0 Hz, 16H, OCH2), 3.49 (t, J ˆ 6.1 Hz, 32H, NCH2), 2.17 (s, 24H, tosyl CH3) ppm; MS (FAB):
‡
m /z ˆ 2386 (M ).
4,7-Bis-(p-tolylsulfonyl)-2,3,5,6,8,9,17,18,20,21,23,24,31,32,34,35,37,38,46,47,49,50,52,53-tetra-
cosahydro-61H,63H-tetrakis-((4,7)-diaza-(1,10)-dioxa)-cyclodecine [5,6-b:51,61-k:511,611-t:5111
,
6
111-c1]phthalocyaninato copper (II) (5; C112H112O24 N16S8Cu)
A mixture of 0.120 g 1 (0.175 mmol), 41 mg CuCN (0.461 mmol), and 0.5 cm3 tmu was heated and
stirred at 180±190ꢁC for 24 h under N2. After cooling to room temperature, the dark-green mixture

Substituted Phthalocyanines
77
was diluted with 10 cm3 EtOH, and the crude product was precipitated. It was ®ltered off and washed
with hot H2O, hot EtOH, and diethyl ether. The precipitate was re¯uxed with a solution of 0.35 g
NaCN in 15 cm3 H2O to remove the excess of CuCN and ®ltered. The dark-green product was
washed with hot H2O, hot EtOH, and diethyl ether and dried. Compound 5 is soluble in CHCl3,
CH2Cl2, DMF, and DMSO.
Yield: 0.050 g (42%); IR (KBr): ꢁ ˆ 3110 (CH aromatic), 2972±2850 (CH aliphatic), 1340 and
‡
1140 (Ar-CH3) cmÀ1; MS (FAB): m /z ˆ 2384 (M ).
Bis-(4,7-bis-(p-tolylsulfonyl)-2,3,5,6,8,9,17,18,20,21,23,24,31,32,34,35,37,38,46,47,49,50,52,53-
tetracosahydro-61H,63H-tetrakis-((4,7)-diaza-(1,10)-dioxa)-cyclodecine [5,6-b:51,61-k:511,611-t:
5111,6111-c1]phthalocyaninato lutetium(III) (6; C224H224O48N32S16 Lu)
A mixture of 0.203 g 2 (0.35 mmol), 15 mg anhydrous lutetium(III) acetate (0.043 mmol), and
0.21 cm3 DBU (0.522 mmol) in 1 cm3 1-hexanol was heated and stirred at 160ꢁC for 20 h under N2.
After cooling to room temperature, the crude product was diluted with 5 cm3 EtOH, ®ltered, dissolved
in CHCl3, and ®ltered again. The ®ltrate was evaporated to dryness, and the residue was washed
several times successivelywith hot H O, EtOH, MeOH, and ethyl acetate. Finally, it was dried
2
in vacuo. Compound 6 is soluble in CHCl3, CH2Cl2, THF, DMF, and DMSO.
Yield: 0.117 g (57%); IR (KBr): ꢁ ˆ 3060 (CH aromatic), 2976±2850 (CH aliphatic), 1340 and
1
1140 (Ar-CH3) cmÀ1; H NMR (CDCl3, ꢂ, 200 MHz): 8.22±6.96 (m, 80H, aromatic H), 4.28±3.62
(m, 32H, OCH2), 3.34±3.26 (m, 64H, NCH2), 2.17 (s, 48H, tosyl CH3) ppm.
Acknowledgements
_
The authors thank the Research Fund of the Technical Universityof Istanbul for support.
È
O. Bekaroglu is grateful to the Turkish Academyof Science (TUBA).
References

[1] Moser FH, Thomas AH (1983) The Phthalocyanines, vols I and II. CRC, Boca Raton; Wohrle D,

Meyer G (1985) Kontakte 3: 38; Wohrle D (1986) ibid 1: 24
[2] Schultz H, Lehman H, Rein M, Hanack M (1991) Struct Bonding 74: 41
[3] Leznoff CC, Lever ABP (eds) (1989) Phthalocyanines; Properties and Applications. VCH,
Weinheim

[4] KorayAR, Ahsen V, Bekaro glu O (1986) J Chem Soc Chem Commun 932; Ahsen V, Yilmazer E,
ꢀ

ꢀ
Ertas M, Bekaroglu O (1988) J Chem Soc Dalton Trans 401

ꢀ
[5] Sarigul S, Bekaroglu O (1989) Chem Ber 122: 291
[6] Okur AI, Gul A, Cihan A, Tan N, Bekaroglu O (1990) Synth React Inorg Metal-Org. Chem 20:

_


ꢀ
1399

ꢀ
[7] Koc ak M, Cihan A, Okur AI, Bekaroglu O (1991) J Chem Soc Chem Commun 578

[8] Gurek A, Ahsen V, Gul A, Bekaroglu O (1991) J Chem Soc Dalton Trans 3367
ꢀ


 


ꢀ
[9] Gumus G, Ozturk ZZ, Ahsen V, Gul A, Bekaroglu O (1992) J Chem Soc Dalton Trans 2485
[10] Vriesema BK, Buter J, Kellogg RM (1984) J Org Chem 49: 110
[11] Piechocki C, Simon J (1985) Nouv J Chim 9: 159


ꢀ

ꢀ
[12] Ahsen V, Gurek A, Musluoglu V, Gul A, Bekaroglu O (1990) Helv Chim Acta 73: 174
[13] Toupance T, Bassoul P, Mineau L, Simon J (1996) J Phys Chem 100: 11704
[14] Toupance T, Ahsen V, Simon J (1994) J Am Chem Soc 116: 5352
[15] Pandoven A, Cozien Y, L'Her M (1991) New J Chem 15: 515
[16] Konami H, Hatano M, Tajiri A (1989) Chem Phys Lett 160: 163
[17] Rodriguez-Mendez ML, Aroca R (1993) Chem Mater 5: 933
[18] Rodriguez-Mendez ML, Aroca R (1992) Chem Mater 4: 1017


ꢀ
T. Ceyhan and O. Bekaroglu: Substituted Phthalocyanines
78
[19] Battisti D, Tomilova L, Aroca R (1992) Chem Mater 4: 1323

[20] Kandaz M, Bekaroglu O (1997) Chem Ber 135: 1833
ꢀ
[21] Kandaz M, Yilmaz I, Bekaroglu O (2000) Polyhedron 19: 115

ꢀ


ꢀ
[22] Kandaz M, Ozkaya AR, Bekaroglu O (2001) Monatsh Chem 132: 1013
[23] Pandoven A, Cozien Y, L'Her M (1992) New J Chem 16: 711
[24] Guyon F, Pandoven A, Guenot P, L'Her M (1994) Inorg Chem 33: 4787
[25] Bouvet M, Simon J (1990) Chem Phys Lett 172: 299
[26] Guyon F, Pandoven A, Kerbaol J, L'Her M (1998) Inorg Chem 37: 569
[27] De Cian A, Moussavi M, Fischer J, Weiss R (1985) Inorg Chem 24: 3162
[28] Piechocki C, Simon J (1985) J Chem Phys Lett 122: 124
[29] Battisti D, Tomilova L, Aroca R (1992) Chem Mater 4: 1323
[30] Corker GA, Grant B, Clecak NJ (1979) J Electrochem Soc 126: 1339

[31] GursoyS, Bekaro glu O (in press)

ꢀ
[32] Koyama H, Yoshino T (1972) Bull Chem Soc Jpn 45: 481
Received May 8, 2001. Accepted (revised) June 25, 2001