Synthesis of novel unsymmetrically substituted push-pull phthalocyanines

Article abstract of DOI:10.1021/jo961018o

The synthesis and characterization of novel non-centrosymmetrically push-pull substituted metal-free phthalocyanines 3-9 are described. The compounds have different donor (dialkoxy, tert-butyl, methyl, p-tolylthio) and/or attractor (p-tolylsulfinyl, p-tolylsulfonyl, nitro) functional groups, are soluble in organic solvents, and are especially designed to study their second- and third-order nonlinear optical properties. Compounds 7-9 are mixtures of the four corresponding regioisomers. For preparing the unsymmetrical phthalocyanines 7-9, the effectiveness of the subphthalocyanine route, using different substituted diiminoisoindolines as reagents, has been tested. Furthermore, a comparison between this method versus the statistical one has been done. The results obtained show that the ring enlargement reaction of subphthalocyanines to obtain unsymmetrically substituted phthalocyanines is not a selective reaction but a multistep process, which depends dramatically on the nature of the substituents on the subphthalocyanines, the reactivity of the iminoisoindoline, the solvent, and other factors that limit its general synthetic utility. Preliminary data of the experimental second-order hyperpolarizabilities of compounds 3-9 are also given.

Full text of DOI:10.1021/jo961018o

J . Org. Chem. 1996, 61, 8591-8597
8591
Syn th esis of Novel Un sym m etr ica lly Su bstitu ted P u sh -P u ll
P h th a locya n in es
AÄ ngela Sastre, Bele´n del Rey, and Toma´s Torres*
Departamento de Quı´mica Orga´nica (C-I), Universidad Auto´noma de Madrid, E-28049-Madrid, Spain
Received May 31, 1996X
The synthesis and characterization of novel non-centrosymmetrically push-pull substituted metal-
free phthalocyanines 3-9 are described. The compounds have different donor (dialkoxy, tert-butyl,
methyl, p-tolylthio) and/or attractor (p-tolylsulfinyl, p-tolylsulfonyl, nitro) functional groups, are
soluble in organic solvents, and are especially designed to study their second- and third-order
nonlinear optical properties. Compounds 7-9 are mixtures of the four corresponding regioisomers.
For preparing the unsymmetrical phthalocyanines 7-9, the effectiveness of the subphthalocyanine
route, using different substituted diiminoisoindolines as reagents, has been tested. Furthermore,
a comparison between this method versus the statistical one has been done. The results obtained
show that the ring enlargement reaction of subphthalocyanines to obtain unsymmetrically
substituted phthalocyanines is not a selective reaction but a multistep process, which depends
dramatically on the nature of the substituents on the subphthalocyanines, the reactivity of the
iminoisoindoline, the solvent, and other factors that limit its general synthetic utility. Preliminary
data of the experimental second-order hyperpolarizabilities of compounds 3-9 are also given.
In tr od u ction
one being the statistical condensation reaction between
two different substituted phthalonitriles8 or diiminoisoin-
dolines.9 The disadvantage of this method is that a
mixture of products is always formed, making their
separation difficult by chromatographic techniques.
Within this context, it is worth noting that the prepa-
ration of unsymmetrical Pcs can be effected through ring
enlargement of subphthalocyanines10 (subPcs, 2) by reac-
tion with substituted diiminoisoindolines. This strategy
was claimed to have three advantages over the mixed
condensation methods: normally relatively good yields
(8-20%), easy purification by column chromatography
of the unsymmetric Pcs, and, most importantly, selectiv-
ity, since only one Pc compound was obtained in the
reaction.10a
Molecules with nonlinear optical (NLO) properties have
been extensively studied because of their potential ap-
plications in optical communications, data storage, and
electrooptical signal processing.1 Increasingly, organic
molecules are becoming targets for these applications
mainly due to their processability and the possibility of
tailoring the molecules with the desired physicochemical
parameters.2,3 Whereas an electron-delocalized organic
system is the single prerequisite for achieving a third-
order nonlinear response, second-order nonlinear effects
are present only in non-centrosymmetric molecules, and
their enhancement has relied on push-pull systems.
Symmetrically substituted phthalocyanines (Pcs, 1)
have emerged as novel targets toward materials with
third-order nonlinear optical applications due to their
extensively delocalized 18 π-electron system and the
possibility of very easily modifying their electronic dis-
tribution by incorporation of different metal atoms in the
center or through peripheral or axial substitution.4
Unsymmetrically substituted phthalocyanines carrying
donor and/or acceptor groups have been suggested as
interesting candidates for second harmonic generation.5
However, up to date very few studies have been carried
out in this area.6 The main reason could be the difficulty
in the preparation and purification of this kind of
phthalocyanine systems.
However, some authors11,12 have reported recently that
the ring enlargement reaction of subPcs for obtaining
Different strategies to synthesize non-centrosymmetric
phthalocyanines have been reported,7 the most common
(7) Phthalocyanines: Properties and Applications; Leznoff, C. C.,
Lever, A. B. P., Eds.; VCH Publishers, Inc.: Weinheim, 1989; Vol. 1,
pp 1-54.
X Abstract published in Advance ACS Abstracts, October 15, 1996.
(1) Shen, Y. R. The Principles of Nonlinear Optics; Wiley: New York,
1984.
(2) Nonlinear Optical Properties of Organic Molecules and Crystals;
Chemla, D. S., Zyss, J ., Eds. Academic Press: New York, 1987; Vols.
1 and 2.
(3) Nonlinear Optics: Materials, Physics and Devices; Zyss, J ., Ed.;
Academic Press: Boston, 1993.
(4) (a) Nalwa, H. S. Adv. Mater. 1993, 5, 341. (b) Phthalocyanines:
Properties and Applications; Leznoff, C. C., Lever, A. B. P., Eds.; VCH
Publishers, Inc: Weinheim, 1996; Vol. 4.
(5) Li, D.; Ratner, A.; Marks, T. J . J . Am. Chem. Soc. 1988, 110,
1707.
(6) (a) Liu, Y.; Xu, Y.; Zhu, D.; Wada, T.; Sasabe, M.; Liu, L.; Wang,
W. Thin Solid Films 1994, 244, 943. (b) Liu, Y.; Xu, Y.; Zhu, D.; Wada,
T.; Sasabe, H.; Zhao, X.; Xie, X. J . Phys. Chem. 1995, 99, 6957.
(8) (a) Vacus, J .; Memetzidis, G.; Doppelt, P.; Simon, J . J . Chem.
Soc., Chem. Commun. 1994, 687. (b) Mckeown, N. B.; Chambrier, I.;
Cook, M. J . J . Chem. Soc., Perkin Trans. 1 1990, 1169.
(9) (a) Linssen, T. L.; Hanack, M. Chem. Ber. 1994, 127, 2051. (b)
Piechocki, C.; Simon, J . J . Chem. Soc., Chem. Commun. 1985, 259.
(10) (a) Kobayashi, N.; Kondo, R.; Nakajima, S.; Osa, T. J . Am.
Chem. Soc. 1990, 112, 9640. (b) Ando, M.; Mori, M. J pn. Kokai Tokkyo
Koho J P 02 09,882 [90 09,882] 1990; Appl. 88/159, 949 1988. Chem.
Abstr. 1990, 113, 25554. (c) Kobayashi, N. J pn. Kokai Tokkyo Koho
J P 0421,684 [9221,684] 1992; Appl. 90/124,258, 1990. Chem. Abstr.
1992, 116, 255643. (d) Geyer, M.; Plenzig, F.; Rauschnabel, J .; Hanack,
M.; del Rey, B.; Sastre, A.; Torres, T. Synthesis 1996, 1139.
(11) Weitemeyer, A.; Kliesch, H.; Wo¨hrle, D. J . Org. Chem. 1995,
60, 4900.
S0022-3263(96)01018-3 CCC: $12.00 © 1996 American Chemical Society

8592 J . Org. Chem., Vol. 61, No. 24, 1996
Sastre et al.
Ch a r t 1
substituted phthalocyanines is actually, in a general way,
a nonselective multistep reaction. Opening and breaking
of the subPc often takes place leading to mixtures of all
possible statistical products.
line18 (16) employed in the synthesis of the unsymmetrical
phthalocyanines were prepared following methods de-
scribed in the literature.
The preparation of the (p-tolylthio)phthalonitrile (17)
was accomplished by ipso substitution on 4-nitrophtha-
lonitrile with p-methylthiophenol in presence of a base
in 90% yield. The oxidation of 17 to the corresponding
sulfinyl and sulfonyl derivatives 18 and 19 was per-
formed using m-chloroperbenzoic acid (m-CPBA) as
oxidizing agent in 94 and 96% yield, respectively. The
diiminoisoindolines 20-22 were obtained in excellent
yields by reacting the corresponding phthalonitriles 17-
19 with NH3(g) in MeOH as solvent and NaOMe as
catalyst (Scheme 1).
Chlorosubphthalocyanine 23 and tri-tert-butylchloro-
subphthalocyanine 24 were prepared following the Meller
and Ossko method,19 as reported previously by us,14c
from the corresponding phthalonitriles in the presence
of BCl3.
The synthesis of the mono- and disubstituted unsym-
metrical phthalocyanines 3-6 was carried out by reaction
of the subphthalocyanine 23 with the appropriate di-
iminoisoindoline (Scheme 2) in N,N-dimethylamino-
ethanol (DMAE) at 80 °C. The ratio diiminoisoin-
doline/subphthalocyanine employed in the reactions was
variable according to the reactivity of each diiminoisoin-
doline.
Thus, from ratios of 3:1 for 13/23 and 9:1 for 14/23,
2,3-bis(octyloxy)phthalocyanine 3 and 2-tert-butylphtha-
locyanine 4 were obtained in 90% and 57% yields,
respectively. In both cases, a small amount of unsub-
stituted phthalocyanine (1, R ) H, M ) H2) coming from
23 was detected by FAB-MS and separated by flash
column chromatography. The lower reactivity of the tert-
butyldiiminoisoindoline 14 in comparison to that of the
bis(octyloxy)diiminoisoindoline 13 makes necessary the
use of a higher excess of 14 to avoid the formation of
significant amounts of 1 (R ) H, M ) H2).
During the last few years we have focused on the
preparation13 and study of NLO properties14 of phthalo-
cyanines and related compounds. This paper reports the
synthesis and characterization of novel non-centrosym-
metrically substituted metal-free phthalocyanines 3-9.
These species are soluble in organic solvents and have
been especially designed to study their second and third-
order nonlinear optical properties. They consist in one
series of mono- and disubstituted Pcs having different
donor [dialcoxy (3), tert-butyl (4), p-tolylthio (5)] or
attractor [p-tolylsulfinyl (6)] functional groups, and an-
other series of tetra- and pentasubstituted push-pull Pcs
containing three tert-butyl groups each and also p-
tolylsulfonyl (7), nitro (8), methyl (9) moieties as sub-
stituents. Moreover, we have prepared three identically
tetrasubstituted Pcs 10-12, bearing p-tolylsulfinyl, p-
tolylsulfonyl, and tert-butyl substituents, in order to
compare their nonlinear optical responses with those of
the noncentrosymmetric ones. Compounds 7-12 are
mixtures of the four corresponding regioisomers.
For preparing the unsymmetrical Pcs we have tested
the effectiveness of the subphthalocyanine method using
different substituted diiminoisoindolines and subphtha-
locyanines as reagents. Furthermore, a comparison
between this method versus the statistical one has been
done.
Resu lts a n d Discu ssion
The 5,6-bis(octyloxy)-1,3-diiminoisoindoline15 (13), 5-tert-
butyl-1,3-diiminoisoindoline16 (14), 5,6-dimethyl-1,3-di-
iminoisoindoline17 (15), and 5-nitro-1,3-diiminoisoindo-
(12) Sastre, A.; Torres, T.; Hanack, M. Tetrahedron Lett. 1995, 36,
8501.
(13) See for example (a) Duro, J . A.; de la Torre, G.; Torres, T.
Tetrahedron Lett. 1995, 36, 8079. (b) Cabezo´n, B.; Rodr´ıguez-Morgade,
S.; Torres, T. J . Org. Chem. 1995, 60, 1872. (c) Ferna´ndez-La´zaro, F.;
Sastre, A.; Torres, T. J . Chem. Soc., Chem. Commun. 1995, 419 and
literature cited therein.
(14) (a) D´ıaz-Garc´ıa, M. A.; Ledoux, I.; Duro, J . A.; Torres, T.; Agullo´-
Lo´pez, F.; Zyss, J . J . Phys. Chem. 1994, 98, 8761. (b) D´ıaz-Garc´ıa, M.
A.; Ledoux, I.; Ferna´ndez-La´zaro, F.; Sastre, A.; Torres, T.; Agullo´-
Lo´pez, F.; Zyss, J . J . Phys. Chem. 1994, 98, 4495. (c) D´ıaz-Garc´ıa, M.
A.; Agullo´-Lo´pez, F.; Sastre, A.; Torres, T.; Toruellas, W. E.; Stegeman,
G. I. J . Phys. Chem. 1995, 99, 14988. (d) Sastre, A.; Torres, T.; D´ıaz-
Garc´ıa, M. A.; Agullo´-Lo´pez, F; Dhenaut, C.; Brasselet, S.; Ledoux, I.;
Zyss, J . J . Am. Chem. Soc. 1996, 118, 2746.
Reaction of bis(octyloxy)diiminoisoindoline 13 with
subPc 23 in pentanol/DBU as solvent at 80 °C affords a
mixture of H2Pc, di-, tetra-, hexa-, and octaalkoxyphtha-
locyanines. Moreover, the lowest yields of 3 were ob-
tained either when DMAE was replaced by a mixture of
dimethyl sulfoxide/dichlorobenzene (DMSO/DCB), sol-
vent normally used in this type of reaction,10,11,20 or when
(17) Metz, J .; Schneider, O.; Hanack, M. Inorg. Chem. 1984, 23,
1065.
(18) (a)Young, J . G.; Onyebuagu, W. J . Org. Chem. 1990, 55, 2155.
(b) Brach, P. J .; Grammatica, S. J .; Ossanna, O. A.; Weinberger, L. J .
Heterocycl. Chem. 1970, 7, 1403.
(15) Van der Pol, J . F.; Neeleman, E.; Zwikker, J . W.; Nolte, R. J .
M.; Drenth, W. Recl. Trav. Chim. Pays-Bas. 1988, 107, 615.
(16) Larner, B. W.; Peters, A. T. J . Chem. Soc. 1952, 680.
(19) Meller, A.; Ossko, A. Monatsh. Chem. 1972, 103, 150.

Novel Unsymmetrically Substituted Push-Pull Phthalocyanines
J . Org. Chem., Vol. 61, No. 24, 1996 8593
Sch em e 1
Sch em e 2
of diiminoisoindoline affords the corresponding unsub-
stituted metallophthalocyanine (1, R ) H, M ) Fe, Ni).
On the other hand, in the preparation of (tolylthio)-
phthalocyanine 5 and (tolylsulfinyl)phthalocyanine 6,
besides free unsubstituted phthalocyanine (H2Pc, 1, R )
H), di- and trisubstituted phthalocyanines were detected
by FAB-MS. The expected phthalocyanines 5 and 6 were
purified from the reaction mixture by column chroma-
tography. These results could be explained by taking into
account the high reactivity of diiminoisoindolines 20 and
21, which facilitates their self-condensation.
Mono- and disubstituted phthalocyanines 3-6 are
scarcely soluble in organic solvents. At room tempera-
ture these compounds are slightly soluble in chloroform
but increasingly so upon heating.
the molar ratio of diiminoisoindoline/subphthalocyanine
was lower than 9:1.
These facts indicate that the solvent plays an essential
role in the mechanism of formation of unsymmetrical Pcs
from subPcs. It has been demonstrated that certain
solvents catalyze the opening of the subPc 23. Thus for
example, when compound 23 was heated overnight in
pentanol or ethoxyethanol at 80 °C, unsubstituted Pc (1,
R ) H, M ) H2) was obtained in moderate yield.
However, when treated under the same reaction condi-
tions in less nucleophilic solvents, such as DMSO/DCB
or DCB/chloronaphthalene or even in DMAE, only traces
of the unsubstituted Pc were observed.
Bis(octyloxy)diiminoisoindoline 13 was also reacted
with subPc 23 in the presence of a metallic salt (FeSO4,
NiCl2) for facilitating a template condensation in order
to obtain only the corresponding metal bis(octyloxy)-
phthalocyaninate, using different molar ratios of the
reactants (from 7:1 to 1:3) in DMAE or DCB/DMSO as
solvents. In agreement with previously reported re-
sults,11,12 the presence of a metal ion increases the yield
of the expected unsymmetrical Pc but also leads to a
higher amount of statistical distribution compounds. The
cleavage of subPc 23 by means of a transition metal ion
has been demonstrated because reaction of 23 with FeSO4
or NiCl2 in the solvents mentioned above in the absence
With the aim of increasing the solubility in organic
solvents, different push-pull tetra- and pentasubstituted
unsymmetrical phthalocyanines 7-9 also have been
synthesized, and a comparative study of the yield ob-
tained employing the subPc route and the diiminoisoin-
doline-statistical method was accomplished (Scheme 3).
Compounds 7-9 were prepared from diiminoisoindo-
lines 22, 16, or 15, respectively, by reaction with tri-tert-
butylsubphthalocyanine (24) in a 4:1 molar ratio using
a mixture of DCB/DMSO (7:3) as solvent. The same
compounds were prepared by the statistical method by
reacting tert-butyldiiminoisoindoline 14 and the corre-
sponding diiminoisoindoline 22, 16, or 15 in a 3:1 molar
ratio using DMAE as solvent (Scheme 3).
Selective formation of the expected substituted phtha-
locyanines 7-9 was not achieved by either method. In
both pathways, besides compounds 7-9 mixtures of all
the statistical condensation products were obtained as
observed by FAB-MS. Thus, for example, in the reac-
tion of subPc 24 with (p-tolylsulfonyl)-1,3-diiminoisoin-
doline (22) it was possible to separate by flash column
chromatography tetra-tert-butylPc 12, the expected tri-
tert-butyl(tolylsulfonyl)Pc 7, and di-tert-butylbis(tolylsul-
fonyl)Pc as pure compounds. In the cases of 8 and 9, due,
respectively, to the limited solubility of the nitro-
substituted Pcs in organic solvents and the similar
retention time of all the alkyl-substituted Pcs, it was only
possible to isolate by chromatographic techniques the
(20) (a) Kasuga, K.; Idehara, M.; Handa, M.; Isa, K. Inorg. Chim.
Acta 1992, 196, 127. (b) Musluoglu, E.; Gu¨rek, A.; Ahsen, V.; Gu¨l, A.;
Bekaroglu, O. Chem. Ber. 1992, 125, 2337.(c) Dabak, S.; Gu¨l, A.;
Bekaroglu, O. Chem. Ber. 1994, 127, 2009.

8594 J . Org. Chem., Vol. 61, No. 24, 1996
Sch em e 3. Su bp h th a locya n in e Meth od
Sastre et al.
tetra-tert-butylPc 12 and the corresponding phthalocya-
nine 8 or 9.
Route b: By cleavage in two fragments, either thermal
or promoted by attack of a solvent molecule (for example
ROH), to afford one or two diiminoisoindoline dimers
such as V, VI, VII and/or VIII, among other possible
products. Self-condensation of two units of VI or VIII
would yield the symmetrically substituted Pc X, whereas
condensation of V and VI, for example, would lead to IV.
On the other hand self-condensation of V or VII could
originate IX.
Route c: Cleavage of tetramer III by attack of diimi-
noisoindoline I to yield different two- or three-unit
compounds that would evolve in a similar way as shown
in route b.
In another route, self-condensation of the diiminoisoin-
doline I would lead to the dimer XI which could react
either with VII, with VIII or self-condense to afford
respectively XII, XIII, or XIV (Scheme 5).
The experimental results found in the present work
are in agreement with the schemes outlined above and
with previous findings reported by us.12 This behavior
should be general for the reactions of subphthalocyanines
and diiminoisoindolines, and the relative importance of
the pathways represented in Schemes 4 and 5 would
depend on the nature of the reactants (substituents,
reactivity) and on the reaction conditions (solvent, tem-
perature).
The overall yields for the preparation of phthalocya-
nines 7-9 are fairly low (3-15%) by either method tried,
mainly due to the numerous purification steps. There-
fore, from the experiments carried out it is not possible
to favor one of the two methods. However, although both
pathways contain the same number of steps, in our
opinion the statistical method is preferable to the sub-
phthalocyanine one because of the higher yields and
easier purification processes in the preparation of the
starting diiminoisoindolines from the corresponding
phthalonitriles in the first case, in comparison with the
preparation of subPcs from the same phthalonitriles by
the second pathway.
Tetrasubstituted phthalocyanines 10 and 11 were pre-
pared as structural isomer mixtures in 33% and 37%
yield, respectively, from the corresponding diiminoisoin-
dolines 21 and 22, after purification by flash chromatog-
raphy.
All the compounds were characterized by NMR, IR,
MS-FAB, UV-visible, and elemental analysis (see Ex-
perimental Section).
All these results and the suggested mechanisms for the
synthesis of related Pcs21 and hemiporphyrazines22 would
allow the pathway depicted in Scheme 4 for the ring
enlargement of subPcs to be proposed. According to this
mechanism, reaction between a diiminoisoindoline I with
a subphthalocyanine II would go through an open four-
unit compound III. This tetramer could evolve in three
different ways depending on the reactants and on the
reaction conditions.
In conclusion, the generally low yields obtained in the
synthesis of Pcs following the subphthalocyanine method
and the results presented here show that the ring
enlargement reaction of subphthalocyanines is not a
selective reaction but a multistep process which depends
dramatically on several factors.
Route a: By cyclization to give the expected Pc IV.
Experimental second order hyperpolarizabilities
γ(-3ω:ω,ω,ω) and γ(-2ω:ω,ω,0)+µâ(-2ω:ω,ω)/5kT have
been determined from THG and EFISH techniques at
1340 and 1060 nm, respectively. The values of γ THG
and γ EFISH found for compounds 3-12 are in the range
of 1 to 5 × 10-33 esu. To the best of our knowledge, no
(21) (a) Petit, M. A.; Plichon, V.; Belkacemi, H. New. J . Chem. 1989,
13, 459. (b) Oliver, S. W.; Smith, T. D. J . Chem. Soc., Perkin Trans. 2
1987, 1579. (c) Kobayashi, N.; Lever, A. B. P. J . Am. Chem. Soc. 1987,
109, 7433.
(22) Rodr´ıguez-Morgade, S.; Torres, T. Inorg. Chim. Acta 1995, 230,
153.

Novel Unsymmetrically Substituted Push-Pull Phthalocyanines
J . Org. Chem., Vol. 61, No. 24, 1996 8595
Sch em e 4
Sch em e 5
room temperature. After removal of the solvent, water was
added and the product was extracted with CH2Cl2 (3 × 50 mL)
and dried over Na2SO4. Yield 90%; white solid; mp 142-143
°C; 1H-NMR (200 MHz, CDCl3) δ 2.44 (s, 3H), 7.2-7.4 (m, 3H),
7.42 and 7.60 (AA′BB′ system, 4H) ppm;13C-NMR (50 MHz,
CDCl3) δ 21.3, 110.7, 115.1, 115.5, 116.0, 124.3, 129.5, 129.6,
131.2, 133.1, 135.3, 141.1, 149.0 ppm; EI-MS m/ z 250 [M+,
previous molecular NLO data in solution of non-cen-
trosymmetric Pcs have been reported. More details about
these measurements will be reported elsewhere.
Exp er im en ta l Section
1,2-Dicya n o-4-(tolylth io)ben zen e (17). A mixture of 520
100], 235 (24); IR (KBr) ν 2200 cm-1
15H10N2S: C, 71.97; H, 4.03; N, 11.24; S, 12.80. Found: C,
71.97; H, 4.09; N, 10.96; S, 12.49.
. Anal. Calcd for
mg (3 mmol) of 3-nitrophthalonitrile,18a 372 mg (3 mmol) of
C
p-methylthiophenol, and 455 mg (4.5 mmol) of K2CO3 in 10
mL of DMSO was stirred for 12 h under argon atmosphere at

8596 J . Org. Chem., Vol. 61, No. 24, 1996
Sastre et al.
1,2-Dicya n o-4-(tolylsu lfin yl)ben zen e (18). To a solution
of 848 mg (2.5 mmol) of m-chloroperbenzoic acid in 30 mL of
CH2Cl2 at -78 °C were slowly added 500 mg (2 mmol) of
(tolylthio)phthalonitrile 17 in 40 mL of CH2Cl2. After the
addition was finished, the temperature was kept at -78 °C
during 30 min. Then, a saturated sodium sulfite solution was
added and the mixture was warmed to room temperature,
extracted with CH2Cl2 (3 × 50 mL), and dried over Na2SO4.
The white solid obtained was purified by column chromatog-
raphy (silica gel, CH2Cl2). Yield 94%; white solid; mp 125 °C;
1H-NMR (200 MHz, CDCl3) δ 2.41 (s, 3H), 7.33 and 7.40
(AA′BB′ system, 4H), 7.8-8.0 (m, 3H) ppm; 13C-NMR (50 MHz,
CDCl3) δ 21.6, 114.1, 114.2, 117.2, 119.5, 128.2, 130.6, 131.6,
132.1, 134.5, 135.8, 146.2, 147.3 ppm; EI-MS m/ z 266 [M+,
100], 250 (60); IR (KBr) ν 2215, 1060, 810, 680 cm-1. Anal.
Calcd for C15H10N2OS: C, 67.65; H, 3.78; N, 10.52; S, 12.70.
Found: C, 67.68; H, 3.83; N, 10.23; S, 12.44.
1,2-Dicya n o-4-(tolylsu lfon yl)ben zen e (19). To a solution
of 848 mg (2.5 mmol) of m-chloroperbenzoic acid in 30 mL of
CH2Cl2 cooled at 0 °C was slowly added 250 mg (1 mmol) of
(tolylthio)phthalonitrile 17 in 25 mL of CH2Cl2. After the
addition was finished, the mixture was warmed to room
temperature and kept for 30 min. Then, a saturated sodium
sulfite solution was added, and the organic phase was ex-
tracted with CH2Cl2 (3 × 50 mL) and dried over Na2SO4. Yield
96%; white solid; mp 170 °C; 1H-NMR (200 MHz, CDCl3) δ
2.45 (s, 3H), 7.39 and 7.84 (AA′BB′ system, 4H), 7.97 (d, 1H,
J ) 8.3 Hz), 8.30 (dd, 1H, J ) 8.3 Hz, J ) 2.5 Hz), 8.52 (d, 1H,
J ) 2.5 Hz) ppm; 13C-NMR (50 MHz, CDCl3) δ 21.6, 114.0,
114.1, 117.1, 119.7, 128.2, 130.6, 131.6, 132.1, 134.5, 135.7,
146.2,147.2; EI-MS m/ z 282 [M+, 100]; IR (KBr) ν 2210, 1320,
1150, 675 cm-1. Anal. Calcd for: C15H10N2OS: C, 63.82; H,
3.57; N, 9.92; S, 11.35. Found: C, 63.85; H, 3.50; N, 10.12; S,
11.27.
Syn t h esis of P h t h a locya n in es. 2,3-Bis(oct yloxy)-
p h t h a locya n in e (3). A mixture of 130 mg (0.3 mmol) of
subphthalocyanine14c 23 and 360 mg (0.9 mmol) of 5,6-bis-
(octyloxy)-1,3-diiminoisoindoline15 (13) in 20 mL of dimeth-
ylaminoethanol was heated at 80 °C for 12 h under an argon
atmosphere. After cooling, the mixture was diluted with 50
mL of MeOH and the precipitate was centrifuged. The solid
was extracted in a Soxhlet apparatus with MeOH for 24 h.
The residue was purified by flash chromatography (SiO2,
eluent CH2Cl2) to afford 208 mg (90%) of a dark green solid.
Mp 240-245 °C; 1H-NMR (200 MHz, CDCl3) δ -2.0 (broad
signal, 2H), 1.04 (t, 6H), 1.9-0.9 (m, 20H), 2.2, (m, 4H), 4.32
(t, 4H), 7.7 (m, 6H), 8.1 (m, 2H), 8.4 (m, 2H), 8.6 (m, 2H), 8.9
(m, 2H) ppm; FAB-MS (3-NOBA) m/ z 771 [M + H+], 770 [M+];
UV/vis (CHCl3) λmax (log ꢀ/dm3 mol-1 cm-1) 695 (5.21), 659
(5.13), 640 (4.74), 599 (4.51), 431 (4.30), 339 (4.91) nm; IR (KBr)
ν 1630, 1615, 1500, 1480, 1450,1290, 1110, 1010, 890, 750 cm-1
.
Anal. Calcd for C48H50N8O2‚2H2O: C, 71.44; H, 6.73; N, 13.88.
Found: C, 71.21; H, 6.83; N, 13.76.
2-ter t-Bu tylp h th a locya n in e (4). This compound was
synthesized from subphthalocyanine 23 (215 mg, 0.5 mmol)
and 5-tert-butyl-1,3-diiminoisoindoline16 14 (905 mg, 4.5 mmol)
in DMAE (20 mL) as solvent, at 80 °C as described for the
preparation of 3. After cooling, the mixture was diluted with
50 mL of MeOH, and the precipitate was centrifuged and
washed with MeOH in a Soxhlet extractor. The product was
finally purified by flash chromatography (SiO2, CH2Cl2/MeOH
20:1). Yield 57%; blue solid; mp > 300 °C; 1H- NMR (200 MHz,
CDCl3) δ 1.9 (s, 9H), 7.7-9.0 (m, 15H) ppm. MS-FAB
(3-NOBA) m/ z 571 [M + H+], 570 [M+]; UV/vis (CHCl3) λmax
(log ꢀ/dm3 mol-1 cm-1): 695 (5.17), 658 (5.13), 639 (4.71), 597
(4.47), 358 (sh), 339 (4.87) nm; IR (KBr) ν 1620, 1350, 1330,
1320, 1020, 890, 760, 750, 730 cm-1
.
Anal. Calcd for
C36H26N8‚H2O: C, 73.44; H, 4.79; N, 19.03. Found: C; 73.30;
H, 4.82; N, 18.94.
5-(Tolylth io)-1,3-d iim in oisoin d olin e (20). Through a
mixture of 750 mg (3 mmol) of dicyano derivative 17 and a
catalytic amount of NaOMe in 40 mL of MeOH was bubbled
NH3 at room temperature for 1 h. Then, the stirred mixture
was refluxed for 4 h maintaining the ammonia flow. After
cooling, the solvent was evaporated and the residue was
washed with an aqueous saturated solution of NH4Cl and
isolated by filtration. Yield 99%; mp 185-186 °C dec; 1H-NMR
(200 MHz, CD3OD) δ 2.41 (s, 3H), 7.29 (d, 1H, J ) 8.3 Hz),
7.37 (dd, 1H, J ) 2.5 Hz, J ) 8.3 Hz), 7.67 (d, 1H, J ) 2.5 Hz),
7.43 and 7.73 (AA′BB′ system, 4H) ppm; 13C-NMR (50 MHz,
CD3OD): 21.3, 121.8, 122.9, 129.9, 131.2, 131.7, 134.7, 135.2,
138.8, 140.6, 145.4, 172.0 ppm; EI-MS m/ z 267 [M+, 100], 145
2-(Tolylth io)p h th a locya n in e (5). Following the same
procedure described in the preparation of 3, starting from a
mixture of subphthalocyanine 23 (130 mg, 0.3 mmol) and
5-(tolylthio)-1,3-diiminoisoindoline (20) (240 mg, 0.9 mmol) in
20 mL of DMAE and after purification of the compound by
flash column chromatography (SiO2, CH2Cl2) was obtained 20
1
mg (11%) of 5 as a dark blue solid. Mp > 300 °C; H-NMR
(200 MHz, CDCl3) δ 2.49 (s, 3H), 7.7-9.0 (m, 19H) ppm; FAB-
MS (3-NOBA) m/ z 637 [M + H+], 636 [M+]; UV/vis (CHCl3)
λmax (log ꢀ/dm3 mol-1 cm-1) 700 (5.00), 663 (5.00), 641 (4.70),
610 (4.49), 424 (sh), 340 (4.87) nm; IR (KBr) ν 1610, 1020, 820,
750 cm-1. Anal. Calcd for C39H24N8S‚H2O: C, 71.54; H, 4.00;
N, 17.11; S, 4.90. Found: C, 71.17; H, 3.89; N, 16.81; S, 5.01.
2-(Tolylsu lfin yl)p h th a locya n in e (6). Compound 6 was
synthesized following the previous described methodology for
the preparation of 3 from 130 mg (0.3 mmol) of subphthalo-
cyanine 23 and 255 mg (0.9 mmol) of 5-(tolylsulfinyl)-1,3-
diiminoisoindoline (21) in 20 mL of DMAE after final purifi-
cation by column chromatography (SiO2, CH2Cl2/MeOH, 15:
1). Yield 10%; dark blue solid; mp > 300 °C. 1H-NMR (200
MHz, CDCl3) δ 2.5 (s, 3H), 7.7-9.0 (m, 19H) ppm; FAB-MS
(3-NOBA) m/ z 653 [M + H+], 652 [M+]; UV/vis (CHCl3) λmax
(log ꢀ/dm3 mol-1 cm-1) 687 (5.11), 661 (5.13), 637 (4.84), 608
(4.64), 341 (4.75) nm; IR (KBr) ν 1620, 1020, 750 cm-1. Anal.
Calcd for C39H24N8OS‚H2O: C, 69.83; H, 3.90; N, 16.70; S, 4.78.
Found: C, 69.65; H, 3.87; N, 16.64; S, 4.82.
(27); IR (KBr) ν 3300, 1700, 1680, 1540 cm-1
. Anal. Calcd
for C15H13N3S‚H2O: C, 63.13; H, 4.59; N, 14.72; S, 11.23.
Found: C, 63.35; H, 4.77; N, 14.50; S, 10.93.
5-(Tolylsu lfin yl)-1,3-d iim in oisoin d olin e (21). Following
the same procedure described above for the synthesis of 20,
from 300 mg (1 mmol) of dicyano derivative 18 and a catalytic
amount of NaMeO in 30 mL of MeOH was obtained 280 mg
(98%) of 21 as a white solid. Mp 145-146 °C dec. 1H-NMR
(200 MHz, CD3OD) δ 2.41 (s, 3H), 7.66 and 7.98 (AA′BB′
system, 4H), 8.0-8.6 (m, 3H) ppm;13C- NMR (50 MHz, CD3-
OD) 21.4, 118.6, 123.5, 126.5, 128.7, 131.5, 138.8, 140.2, 142.4,
144.2, 150.5, 171.7, 171.5 ppm; EI-MS m/ z 283 [M+, 100], 267
(25); IR (KBr) ν 3300, 1710, 1680, 1550, 1060, 810, 650 cm-1
.
Anal. Calcd for C15H13N3OS‚H2O: C, 59.78; H, 5.01; N, 13.94;
S, 10.64. Found: C, 59.94; H, 4.99; N, 13.84; S, 10.52.
5-(Tolylsu lfon yl)-1,3-d iim in oisoin d olin e (22). Follow-
ing the same procedure described above for the synthesis of
20 from 570 mg (2 mmol) of dicyano derivative 19 and a
catalytic amount of NaMeO in 40 mL of MeOH was obtained
550 mg (92%) of 22 as a white solid. Mp 220-222 °C dec;
1H- NMR (200 MHz, CD3OD) δ 2.43 (s, 3H), 7.4 and 7.9
(AA′BB′ system, 4H), 8.04 (d, 1H, J ) 8.3), 8.14 (dd, 1H, J )
8.3 Hz, J ) 2.5 Hz), 8.50 (d, 1H, J ) 2.5 Hz) ppm; 13C- NMR
(50 MHz, CD3OD) δ 21.5, 121.8, 123.5, 126.5, 131.3, 131.8,
138.8), 139.2, 141.7, 146.5, 170.4, 171.7, 171.5 ppm; EI-MS m/ z
299 [M+, 100]; IR (KBr) ν 3300, 1710, 1680, 1550, 1320, 1150,
9,16,23-Tr i-t er t -b u t yl-2-(t olylsu lfon yl)p h t h a locya -
n in e23 (7). (a ) Su bp h th a locya n in e Meth od . A mixture of
tri-tert-butylsubphthalocyanine (24) (240 mg, 0.4 mmol) and
5-(tolylsulfonyl)-1,3-diiminoisoindoline (22) (480 mg, 1.6 mmol)
in 7 mL of DCB and 3 mL of DMSO was heated at 80 °C for
24 h. After cooling at room temperature the reaction mixture
was treated with methanol and the precipitate filtered off
obtaining a blue solid. From the complex mixture (TLC) of
phthalocyanines was separated 9 mg (3%) of 7 by flash column
chromatography (SiO2, CH2Cl2). Mp > 300 °C; 1H- NMR (200
MHz, CDCl3) δ -2.92 (s, 1H), -2.71 (s, 1H), 1.8-2.1 (m, 27H),
2.50, 2.51 (2xs, 3H), 7.4-9.6 (m, 16H) ppm; FAB-MS (3-NOBA)
675 cm-1
. Anal. Calcd for C15H13N3O2S‚H2O: C, 56.77; H,
5.08; N, 13.24; S, 10.10. Found: C, 56.80; H, 4.88; N, 13.13;
S, 9.99.
(23) For simplicity reasons, only one of the four structural isomers
will be named as example.

Novel Unsymmetrically Substituted Push-Pull Phthalocyanines
J . Org. Chem., Vol. 61, No. 24, 1996 8597
m/ z 837 [M + H+], 836 [M+]; UV/vis (CHCl3) λmax (log ꢀ/dm3
mol-1 cm-1) 711 (sh), 687 (5.00), 618 (4.33), 341 (4.59) nm; IR
(KBr) ν 1620, 1330, 1170, 1020, 750, 690 cm-1. Anal. Calcd
for C51H48N8O2S‚2H2O: C, 70.16; H, 6.00; N, 12.83; S, 3.65.
Found: C, 70.10; H, 5.90; N, 12.71; S, 3.74.
From the above mentioned column chromatography was
isolated 4 mg (0.7%) of d i-ter t-b u t ylb is(t olylsu lfon yl)-
p h th a locya n in e. Mp > 300 °C; 1H- NMR (200 MHz, CDCl3)
δ -4.5 to 4.9 ppm (2 broad signals, 2H), 1.7-1.9 (broad signal,
18H), 2.5-2.6 (m, 6H), 7.5-9.3 (m, 20H) ppm; FAB-MS (3-
NOBA) m/ z 935 [M + H+], 934 [M+];UV/vis (CHCl3) λmax (log
ꢀ/dm3 mol-1 cm-1) 698 (5.09), 669 (5.01), 642 (4.60), 614 (4.50),
347 (4.86) nm; IR (KBr) ν 1630, 1620, 1330, 1170, 1020, 750
690 cm-1. Anal. Calcd for C54H46N8O4S2‚H2O: C, 68.05; H,
5.07; N, 11.75; S, 6.73. Found: C, 68.17; H, 4.98; N, 11.70; S,
6.81.
(b) Sta tistica l Meth od . A mixture of 1.8 g (9 mmol) of
5-tert-butyl-1,3-diiminoisoindoline16 (14) and 897 mg (3 mmol)
of 5-(tolylsulfonyl)-1,3-diiminoisoindoline (22) in 10 mL of
DMAE was heated at 150 °C for 7 h under an argon
atmosphere. The reaction mixture was treated with MeOH
and the precipitate filtered. After flash column chromatog-
raphy (SiO2, CH2Cl2), 240 mg (9%) of 7 and 181 mg (13%) of
di-tert-butylbis(tolylsulfonyl)phthalocyanine were obtained.
washed with hot methanol. Compound 9 was purified by flash
column chromatography (SiO2, toluene/hexane 5:2) to afford
1
13 mg (4%) of 9. Mp > 300 °C; H-NMR (200 MHz, CDCl3) δ
1.9 ppm (broad signal, 27H), 2.4 (s, 6H), 7.4-9.5 (m, 11H) ppm;
FAB-MS (3-NOBA) m/ z 711 [M + H+], 710 [M+]; UV/vis
(CHCl3) λmax (log ꢀ/dm3 mol-1 cm-1) 701 (5.10), 664 (5.04), 644
(4.57), 603 (4.28), 342 (4.80) nm; IR (KBr) ν 2960, 2800, 2780,
1615, 1480, 1100, 755 cm-1
2H2O: C, 73.96; H, 6.74; N, 15.00. Found: C, 73.94; H, 6.82;
N, 15.34.
. Anal. Calcd for: C46H46N8‚
(b) Sta tistica l Meth od . A mixture of 540 mg (2.7 mmol)
of 5-tert-butyl-1,3-diiminoisoindoline (14) and 156 mg (0.9
mmol) of 5,6-dimethyl-1,3-diiminoisoindoline (15) in 5 mL of
DMAE was heated at 150 °C for 24 h. The reaction mixture
was treated as described above to yield 40 mg (12%) of 9.
2,9,16,23-Tetr a k is(tolylsu lfin yl)p h th a locya n in e23 (10).
5-(Tolylsulfinyl)-1,3-diiminoisoindoline (18) (425 mg, 1.5 mmol)
in 10 mL of DMAE was heated at 150 °C for 7 h. After cooling,
20 mL of methanol was added and a blue solid precipitated.
Purification by flash column chromatography (SiO2, CH2Cl2/
1
MeOH 15:1) afforded 142 mg (36%) of 10. Mp > 300 °C; H-
NMR (200 MHz, CDCl3) δ 2.0-2.6 (broad signal, 12H), 7.4-
9.5 (m, 28H) ppm; FAB-MS (3-NOBA) m/ z 1067 [M + H+],
1066 [M+]; UV/vis (CHCl3) λmax (log ꢀ/dm3 mol-1 cm-1): 701
(5.09), 665 (5.03), 645 (4.67), 638 (4.66), 605 (4.47), 346 (4.85)
nm; IR (KBr) ν 1590, 1060, 800, 740 cm-1. Anal. Calcd for
C60H42N8O4S4‚H2O: C, 66.40; H, 4.06; N, 10.32; S, 11.82.
Found: C, 66.33; H, 3.90; N, 10.40; S, 11.89.
9,16,23-Tr i-ter t-bu tyl-2-n itr op h th a locya n in e23,24 (8). (a )
Su bp h th a locya n in e Meth od . Compound 8 was synthesized
in a similar way to 7 starting from 310 mg (0.55 mmol) of tri-
tert-butylsubphthalocyanine10a (24) and 410 mg (2.2 mmol) of
5-nitro-1,3-diiminoisoindoline18b (16) in 7 mL of DCB and 3
mL of DMSO. After cooling, the reaction mixture was treated
with diethyl ether and centrifuged. The residue was washed
with hot MeOH and then extracted with toluene in a Soxhlet
apparatus, yielding 60 mg (15%) of 8. Mp > 300 °C; 1H-NMR
(200 MHz, CDCl3) δ 1.6-1.7 (m, 27H), 7.4-8.5 (m, 12H) ppm;
FAB-MS (3-NOBA) m/ z 728 [M + H+], 727 [M+]; UV/vis
(CHCl3) λmax (log ꢀ/dm3 mol-1 cm-1) 692 (5.00), 679 (5.01), 644
(4.70), 624 (4.64), 337 (4.80) nm; IR (KBr) ν 1680, 1550, 1360
cm-1. Anal. Calcd for: C44H41N9O2‚H2O: C, 70.85; H, 5.80;
2,9,16,23-Tetr a k is(tolylsu lfon yl)p h th a locya n in e23 (11).
5-(Tolylsulfonyl)-1,3-diiminoisoindoline (22) (450 mg, 1.5 mmol)
in 10 mL of DMAE was heated at 150 °C for 7 h. After cooling,
20 mL of methanol was added and a blue solid precipitated.
Purification by flash column chromatography (SiO2, CH2Cl2/
MeOH, 40:1) led to 138 mg (33%) of 11. Mp > 300 °C. 1H-
NMR (200 MHz, CDCl3) δ 2.4-2.6 (4xs, 12H), 7.4-10.0 (m,
28H) ppm; FAB-MS (3-NOBA) m/ z 1131 [M + H+], 1130 [M+];
UV/vis (CHCl3) λmax (log ꢀ/dm3 mol-1 cm-1): 701 (5.09), 664
(5.00), 647 (4.55), 636 (4.54), 602 (4.35), 349 (4.76) nm; IR (KBr)
ν
1590, 1300, 1150, 690 cm-1
C60H42N8O8S4‚2H2O: C, 61.43; H, 3.97; N, 9.60; S, 10.99.
.
Anal. Calcd for:
N, 16.90. Found: C, 70.73; H, 5.64; N, 16.90.
(b) Sta tistica l Meth od . A mixture of 542 mg (3 mmol) of
5-tert-butyl-1,3-diiminoisoindoline (14) and 180 mg (1 mmol)
of 5-nitro-1,3-diiminoisoindoline (16) in 5 mL of DMAE was
stirred at reflux temperature under an argon atmosphere for
7 h. After cooling, MeOH was added and a dark green powder
precipitated. Purification by flash column chromatography
(SiO2, hexane/CHCl3, 1:2) afforded 14 mg (2%) of 8.
9,16,23-Tr i-ter t-bu tyl-2,3-dim eth ylph th alocyan in e23 (9).
(a ) Su bp h th a locya n in e Meth od . A mixture of 270 mg (0.48
mmol) of tri-tert-butylsubphthalocyanine (24) and 330 mg (1.92
mmol) of 5,6-dimethyl-1,3-diiminoisoindoline17 (15) in a mix-
ture of 7 mL of DCB and 3 mL of DMSO was heated at 80 °C
for 20 h under an argon atmosphere. After cooling, the solvent
was removed under reduced pressure and the residue was
Found: C, 61.74; H, 3.92; N, 9.55; S, 10.52.
Ack n ow led gm en t. This work is dedicated to Pro-
fessor Michael Hanack on the occasion of his 65th
birthday. This work was supported by the EC (HCM
program, ERBCHRX-CT94-0558), the CICYT (Spain)
MAT96/0654, and the COMUNIDAD DE MADRID
(Spain) AE000333/95.
Su p p or tin g In for m a tion Ava ila ble: Assignment of the
13C NMR signals of the compounds 17-22 (1 page). This
material is contained in libraries on microfiche, inmediately
follows this article in the microfilm version of the journal, and
can be ordered from the ACS; see any current masthead page
for ordering information.
(24) Liu, Y.; Zhu, D.; Wada, T.; Yamada, A.; Sasabe, H. J . Heterocycl.
Chem. 1994, 31, 1017.
J O961018O