Triazoleporphyrazines: A new class of intrinsically unsymmetrical azaporphyrins

Article abstract of DOI:10.1002/1099-0690(200208)2002:15<2460::AID-EJOC2460>3.0.CO;2-H

Triazoleporphyrazine 5 has been prepared by means of a 3+1 crossover condensation of the pyrroline derivative 6 with 3,5-diamino-1,2,4-triazole. Metallation of 5 under standard conditions afforded the metallotriazoleporphyrazines 7. In contrast with the porphyrinic nature observed for its triazoleporphyrin counterpart 3, the free base triazoleporphyrazine 5 possessed a cross-conjugated, hemiporphyrazine-like character. On the other hand, the metallated macrocycles 7 exhibited spectroscopic features that suggested a triazolephthalocyanine-porphyrazine hybrid structure for these compounds. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.

Full text of DOI:10.1002/1099-0690(200208)2002:15<2460::AID-EJOC2460>3.0.CO;2-H

FULL PAPER
Triazoleporphyrazines: A New Class of Intrinsically Unsymmetrical
Azaporphyrins
[b]
[a]
[a]
´
´
´
Mikhail K. Islyaikin, M. Salome Rodrıguez-Morgade, and Tomas Torres*
Keywords: Phthalocyanines / Porphyrazine / Porphyrins / Triazolephthalocyanine / Triazoleporphyrazine
Triazoleporphyrazine 5 has been prepared by means of a
‘‘3+1’’ crossover condensation of the pyrroline derivative 6
with 3,5-diamino-1,2,4-triazole. Metallation of 5 under stand-
character. On the other hand, the metallated macrocycles 7
exhibited spectroscopic features that suggested a triazoleph-
thalocyanine-porphyrazine hybrid structure for these com-
ard conditions afforded the metallotriazoleporphyrazines 7. pounds.
In contrast with the porphyrinic nature observed for its tria-
zoleporphyrin counterpart 3, the free base triazoleporphyraz- ( Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany,
ine 5 possessed a cross-conjugated, hemiporphyrazine-like
2002)
Introduction
shift of its Q-band relative to the corresponding phthalocy-
anine absorption. Thus, while the UV/Vis spectrum of
(tetra-tert-butylphthalocyaninato)nickel(II), for example, is
dominated by an intense absorption centered at 670 nm, tri-
tert-butyl-substituted (triazolephthalocyaninato)nickel(II)
displays its Q-band at the shorter wavelength of 623 nm.
Our research group has been involved for several years in
the design of new core-modified azaporphyrins and
phthalocyanines.[1Ϫ5] One of our main topics is the modi-
fication of the azaporphyrinic ring by replacement of one
or more isoindole subunits of the phthalocyanine skeleton
by other heterocycles such as 1,2,4-triazole and 1,3,4-thiadi-
azole. We have hence synthesized a variety of triazolehemi-
porphyrazines,[3] and have studied their optical and liquid
crystalline properties.[3] Furthermore, we have prepared het-
erobinuclear and heterotrinuclear phthalocyanine-hemipor-
phyrazine hybrids with extended conjugation[6] and have re-
ported the first examples of triazolehemiporphyrazine[7]
and thiadiazolehemiporphyrazine,[8] expanded heteroannul-
enes with unusual coordination features, such as the ability
to bind two or three metal ions, respectively, within their
central cavities.
In addition, we have described the synthesis, character-
ization,
and
study
of
the
properties
of
"triazolephthalocyanines" (1).[9] These intrinsically unsym-
metrical compounds, reported for the first time by us in
1994,[10] are aromatic phthalocyanine analogues in which
one isoindole moiety has formally been replaced by a 1,2,4-
triazole subunit. The introduction of this heterocycle into
the phthalocyanine framework gives rise to a lower degree
of electronic delocalization, which results in a hypsochromic
The lack of any symmetry center in these derivatives
makes them good targets for the development of materials
with nonlinear optical applications.[11,12] Furthermore,
macrocycles substituted with six lipophilic chains show li-
quid-crystal behavior, and their amphiphilic structure, char-
acterized by a polar 1,2,4-triazole head and an aromatic
[a]
´
´
´
Departamento de Quımica Organica, Universidad Autonoma
de Madrid
Cantoblanco, 28049 Madrid
Fax: (internat.)ϩ34Ϫ91/3973966
E-mail: tomas.torres@uam.es
[b]
Department of Fine Organic Synthesis, Ivanovo State
University of Chemistry and Technology
Engels 7, Ivanovo, Russia 153460
macrocycle,
is
especially
appropriate
for
LangmuirϪBlodgett film formation.[9]
2460
 WILEY-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002 1434Ϫ193X/02/0815Ϫ2460 $ 20.00ϩ.50/0 Eur. J. Org. Chem. 2002, 2460Ϫ2464

Triazoleporphyrazines, Intrinsically Unsymmetrical Azaporphyrins
FULL PAPER
Despite all the characteristics described above, there are tography on silica gel, with a 4:1 mixture of hexane and
two main problems that reduce the potential of these metal- dioxane as eluent, afforded macrocycle 5 in 42% yield.
lomacrocycles. One of these, associated with their pseudo-
phthalocyanine nature, is the limited solubility of many of
these derivatives in organic solvents. This fact in itself con-
stitutes a drawback to their practical usefulness, and to-
gether with their tendency to aggregate in solution, makes
their purification and characterization more difficult. The
second point concerns their synthetic availability. The syn-
thesis of nickel- and copper-metallated triazolephthalocy-
anines can be carried out straightforwardly, either in one
step, by crossover condensation of a diiminoisoindoline de-
rivative with 3,5-diamino-1,2,4-triazole in the presence of a
metal salt,[9] or stepwise, by template condensation of a
three-unit intermediate and a diiminoisoindoline.[13] Con-
versely, the introduction of other inner metals remains a
difficult task,[9] and only very recently have we succeeded in
the preparation of some metal-free derivatives.[14] However,
their purification is even more arduous than that of the
metallated compounds, and in some cases impracticable due
to their lability in silica gel.
As a possible approach to solving some of these prob-
lems, we wondered whether the corresponding triazolepor-
phyrazines 2 could be synthesized from substituted maleon-
itriles, by similar procedures. The development of such a
methodology might provide a route to more soluble prod-
ucts with less tendency to aggregate in solution, and there-
fore easier to purify and characterize. In addition, the dif-
ferent chemical properties and stabilities of porphyrazines
and phthalocyanines drove us to anticipate some differences
for the new series Ϫ such as, for example, stronger coupling
between the peripheral substituents and the macrocyclic
core Ϫ that might be advantageous for some kinds of ap-
plications. Thus, as an extension of our work in this field,
we report previous studies on the preparation and charac-
terization of novel core-modified porphyrazines that we
have named triazoleporphyrazines.
Scheme 1
Results and Discussion
Comparison of the conditions described above with those
required for the preparation of the metal-free triazoleph-
2,3-Bis(tert-butylphenyl)fumaronitrile 4[15] was chosen as thalocyanine counterparts, reveals triazoleporphyrazine 5
a precursor, since this kind of substitution should produce to be more stable than the latter. Thus, metal-free triazo-
soluble compounds and be inert enough under the reac- lephthalocyanines cannot be obtained in alcoholic solvents
tion conditions.
such as butanol or 2-ethoxyethanol, due to their tendency
The preparation of porphyrazines is usually carried out to be cleaved by nucleophilic attack on their iminic double
by Linstead macrocyclization[16] of suitably functionalized bonds;[9,18] the use of other polar solvents such as butyron-
maleonitrile derivatives. This method, which involves the itrile is therefore necessary.[14] Furthermore, triazoleporphy-
magnesium-template tetramerization of a dinitrile or its razine 5 can be synthesized directly from a pyrrolinediimine
pyrroline derivative, followed by demetallation by treatment precursor in the absence of any metal-template or base, an
with acids to afford the free-base porphyrazine and further unusual fact that contrasts with the standard synthetic pro-
metallation with a suitable metal salt, is not necessary for cedure to obtain porphyrazines.[19]
the synthesis of the triazole-derived analogues. Triazolepor-
The metal complexes 7aϪc were each prepared by treat-
phyrazine 5 was prepared by direct condensation of the ment of the free base 5 with the appropriate metal acetate in
pyrrolinediimine 6[17] and 3,5-diamino-1,2,4-triazole DMF at 100 °C. Under these conditions, yields of 78Ϫ90%
(guanazole), in stoichiometric ratio, in anhydrous n-butyl (33Ϫ38% overall yield with respect to guanazole) were
alcohol at reflux temperature (Scheme 1). Column chroma- achieved.
Eur. J. Org. Chem. 2002, 2460Ϫ2464
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´
M. K. Islyaikin, M. S. Rodrıguez-Morgade, T. Torres
FULL PAPER
Metallotriazoleporphyrazines may alternatively be syn-
thesized by the reported procedure for nickel(II) triazole-
phthalocyaninatos,[10] which consists of the crossover mac-
rocyclization of the pyrrolinediimine 6 and guanazole in 2-
ethoxyethanol at 135 °C, in the presence of a metal tem-
plate. This method, however, was less efficient than the step-
wise procedure. Thus, for example, 7a with a nickel(II) ion
within its central binding core was obtained in 14% yield
after purification of the crude material by chromatography
on silica gel with a 4:1 mixture of hexane and dioxane as
eluent. Macrocycles 5 and 7aϪc were characterized by
NMR, UV, MS, and IR.
The free base triazoleporphyrazine 5 possesses an 18π-
electron, cross-conjugated, nonaromatic structure, similar
to that of the phthalocyanine-derived series,[14] as evidenced
by its spectroscopic features discussed below. The electronic
alteration of macrocycle 5 with respect to its analogous tria-
zoleporphyrin 3[20] does not correlate with the changes pro-
duced by the formal replacement of the four meso-carbon
Figure 1. UV/Vis spectra of (a) 5 (c ϭ 2.10 ϫ 10Ϫ5) and (b) 5 ϩ
DBU (c ϭ 1.80 ϫ 10Ϫ5) in chloroform
bridges in the porphyrin ring by four meso-nitrogens, on to the same protons in the pyrrolinediimine precursor 6,
going from porphyrins to porphyrazines. Tetraazaporphyr- suggested the absence of aromaticity in macrocycle 5. We
ins (porphyrazines) may be regarded as porphyrin-phthalo- were unable to detect any signal that might be attributable
cyanine hybrids, although they are more similar to the lat- to the triazolic proton.[22] Still, the nonaromatic nature of
ter, and they exhibit electronic properties that differ sub- the free base derivative 5 was clearly manifested by a broad
stantially from those displayed by porphyrins. Hence, signal at δ ϭ 15.2 ppm corresponding to the pyrrole NH,
whereas the UV/Vis spectra of the porphyrins are domin- the low-field shift of which denoted not only the presence
ated by a band in the blue region at ca. 400Ϫ450 nm (Soret of intramolecular hydrogen bonds, but also, and more im-
band), the electronic spectra of tetraazaporphyrins are char- portantly, the lack of a diamagnetic ring current in this
acterized by a blue-shifted, less intense Soret band, accom- compound.[23]
panied by other equally intense absorptions, in the red re-
On the other hand, metallotriazoleporphyrazines are far
from being just the porphyrazinic version of metallated tria-
gion namely a Q-band, in the 550Ϫ700 nm range.[19]
The substitution of a pyrrole ring in the porphyrin frame- zolephthalocyanines, but may be viewed rather as porphyra-
work by the 1,2,4-triazole moiety does not produce any sub- zine/triazolephthalocyanine hybrids. Hence, whereas their
stantial change in the porphyrin nature apart from the con- UV/Vis profiles resembled those of their triazolephthalocy-
sequent loss of symmetry, from D4h to C2v. As a result, the anine counterparts, macrocycles 7aϪc exhibited B and Q-
aromatic 2,3-diazaporphyrin 3 exhibits a strong, split Soret bands in the same wavelength ranges as metal(II) octakis-
band centered at 406 nm,[20] whereas the corresponding B- (tert-butylphenyl)porphyrazinato,[15] with lowest-energy ab-
band of 2,3,7,8,12,13,17,18-octaethylporphyrin appears at sorptions of 602Ϫ630 nm denoting their aromatic, porphyr-
398 nm.[21] Consequently, on going from porphyrazines to azinic nature (Figure 2). The different character of free base
triazoleporphyrazines we should expect typical broadened and metallated triazoleporphyrazines was also evidenced by
1
or split porphyrazinic bands in the UV/Vis, as a con- their NMR spectra. In its H NMR, compound 7a showed
sequence of the symmetry reduction. In contrast, the differ- four well resolved doublets centered at δ ϭ 8.08, 8.02, 7.61
ent electronic properties of the triazoleporphyrazine 5 with and 7.52 ppm, attributable to the benzene rings that are de-
respect to the similarly substituted octakis(tert-bu- shielded by 0.1Ϫ0.3 ppm with respect to the two doublets
tylphenyl)porphyrazine were diagnostic of its altered char- displayed by the pyrroline derivative,[17] as a consequence
acter.
of the porphyrazinic diatropicity.
The UV/Vis spectrum of compound 5 (Figure 1), which
The divergent results obtained by substitution of a pyr-
did not fit the characteristic porphyrazine pattern, was role in a porphyrin and a porphyrazine, or an isoindole in
made up of four sharp absorptions at 323, 417, 486, and a phthalocyanine, by a 1,2,4-triazole ring, must emanate
530 nm. This means that the lowest-energy band displayed from the different features of the meso-carbon and nitrogen
by 5 was blue-shifted by 136 nm in comparison with the bridges. The stabilization of the 1H- or 2H-tautomers relat-
equivalent absorption of its counterpart porphyrazine.[15]
ive to the 4H-tautomer in 1,2,4-triazoles is well estab-
1H NMR spectroscopy of compound 5 demonstrated lished,[24] and has been associated with the formation of
that this phenomenon should not just be attributed to a cyclic dimer-type hydrogen bonds involving the N-1 and N-
lower degree of electronic delocalization in triazoleporphyr- 2 atoms of the rings, with an exchange of the protons be-
azines than in porphyrazines. Thus, the chemical shift of tween two molecules.[25] Taking into account that these hy-
δ ϭ 7.23 ppm observed for the phenyl protons of the free drogen bonds are strongly influenced by the nature of the
base 5, high-field shifted by 0.5 and 0.3 ppm with respect substituents at the 3- and the 5-positions,[25] we can expect
2462
Eur. J. Org. Chem. 2002, 2460Ϫ2464

Triazoleporphyrazines, Intrinsically Unsymmetrical Azaporphyrins
FULL PAPER
techniques is the result of their lower degree of aggregation
in solution, as would be expected from their porphyrazinic
nature. On the other hand, the synthetic availability of dif-
ferent metallo complexes by straightforward metallation of
the stable metal-free derivative has been proven, and opens
a wide range of possibilities for these intrinsically unsym-
metrical compounds. The synthesis of other metallotriazo-
leporphyrazines bearing substituents of different character,
such as donor or acceptor, and their application for second
harmonic generation are under investigation.
Experimental Section
General Remarks: UV/Vis spectra were recorded with
a
Figure 2. UV/Vis spectra of 7a (c ϭ 1.71 ϫ 10Ϫ5), 7b (c ϭ 2.05 ϫ
10Ϫ5), and 7c (c ϭ 7.65 ϫ 10Ϫ6) in chloroform
HewlettϪPackard 8453 instrument. IR spectra were recorded on a
Bruker Vector 22 spectrophotometer. FAB-MS and HRMS spectra
were determined on a VG AutoSpec instrument. MALDI-TOF MS
was performed with a Bruker Reflex III spectrometer. NMR spec-
tra were recorded with BRUKER WM 200 SY, BRUKER AC 300,
and BRUKER DRX 500 instruments. Elemental analyses were per-
formed with a PerkinϪElmer 2400 apparatus. Column chromato-
different proclivities to tautomerize towards the 4H-isomer
for triazoleporphyrins and triazoleazaporphyrins. Thus, the
achievement of an energetically more favored macroarom-
graphy was carried out on Merck 60 silica gel (230Ϫ400 mesh, 60
˚
atic structure could be the driving force for an unusual tria- A), and TLC on aluminum sheets precoated with 60 F254 silica gel
(E. Merck). Chemicals were purchased from Aldrich Chemical Co.
and used as received without further purification.
zolic prototropic shift to the 4H-tautomer in the case of
triazoleporphyrins. However, the stronger tendency towards
hydrogen binding of their meso-nitrogen-bridged counter-
parts (namely the triazoleporphyrazines), and consequently
their lesser ability to tautomerize, would prevent the ful-
fillment of the corresponding 18π-electron, aromatic tauto-
mer. The introduction of a metal(II) into the heteroannu-
lene central cavity with concomitant deprotonation of the
macrocycle shifts the equilibrium towards a ‘‘4H-triazole
arrangement’’, with a subsequent dramatic change in the
character of the macrocycle. The last hypothesis was sup-
ported by the electronic changes observed on deprotonation
of 5 with DBU. In this case the anion of triazoleporphyraz-
ine 5 displayed a UV/Vis spectrum resembling those exhib-
ited by the metal complexes 7aϪc (see Figures 1 and 2
above), with a lowest-energy absorption at 592 nm, similar
to that of the (triazoleporphyrazinato)nickel(II) complex
7a.
Triazoleporphyrazine (5): A mixture of the pyrroline derivative 6
(320 mg, 0.90 mmol) and 3,5-diamino-1,2,4-triazole (30 mg,
0.30 mmol) in anhydrous n-butyl alcohol (30 mL) was heated under
reflux for 30 hours. The dark brown mixture was allowed to cool
to room temperature and, after addition of MeOH (50 mL), the
resulting precipitate was filtered, triturated with MeOH (2 ϫ
50 mL), and dried. Column chromatography on silica gel, with a
4:1 mixture of hexane and dioxane, and further trituration with
hexanes afforded 5 as a dark red solid. Yield 140 mg (42%). 1H
NMR (C2D2Cl4, 300 MHz): δ ϭ 15.24 (broad s, 1 H, NH),
7.26Ϫ7.21 (broad s, 24 H, arom), 1.24, 1.17, 1.16 (3 ϫ s, 54 H,
tBu) ppm. IR (KBr): ν˜ ϭ 3460, 3380 (NϪH), 3299 (NϪH, pyrrole),
2962, 2904, 2868 (CϪH), 1608, 1586 (CϭN), 1494, 1475, 1461,
1392, 1363, 1269, 1109, 1088, 1021, 971, 835 cmϪ1. UV/Vis
(CHCl3): λmax (log ε) ϭ 242 (4.81), 323 (4.55), 417 (4.48), 486
(4.29), 530 nm (4.32). MS (LSIMS, m-NBA): m/z ϭ 1109 [Mϩ],
1110 [M ϩ H]ϩ, 1111 [M ϩ 2 Hϩ], 1112 [M ϩ 3 Hϩ], 1113 [M ϩ
4 Hϩ], 2218 [2 Mϩ], 2219 [2 M ϩ Hϩ], 2220 [2 M ϩ 2 Hϩ], 2221
[2 M ϩ 3 Hϩ], 2222 [2 M ϩ 4 Hϩ]. C74H80N10: calcd. C 80.1, H
7.3, N 12.6; found C 80.3, H 7.5, N 12.6.
Conclusions
(Triazoleporphyrazinato)nickel(II) (7a): A mixture of 5 (44 mg,
0.04 mmol) and Ni(OAc)2·4H2O (32 mg, 0.12 mmol) in DMF
(15 mL) was stirred at 100 °C for 6 h. The reaction mixture was
New core-modified porphyrazine analogues, arising from
the formal replacement of a pyrrole ring in the porphyraz-
inic skeleton by a 1,2,4-triazole moiety, have been synthe- allowed to cool to room temperature and was then poured into
water (100 mL). The resulting precipitate was filtered, and washed
thoroughly with 1% ammonia solution, then with water, and finally
with MeOH to give 44 mg, (90%) of a dark red solid. 1H NMR
(CDCl3, 200 MHz): δ ϭ 8.08, 8.02 (2 ϫ d, J ϭ 7.5 Hz, 12 H, arom),
7.61 (d, J ϭ 7.5 Hz, 4 H, arom), 7.52 (d, J ϭ 7.5 Hz, 8 H, arom),
1.48 (broad s, 54 H, tBu) ppm. 13C NMR (CDCl3, 125 MHz): δ ϭ
159.0 (C1, C4), 152.6, 151.8 (C6, C9, C11, C14, C16, C19),
147.0Ϫ145.0 (C4Ј), 143.0Ϫ142.0 (C1Ј), 133.0Ϫ132.0 (C3Ј),
129.5Ϫ128.5 (C7, C8, C12, C13, C17, C18), 126.5Ϫ125.0 (C2Ј), 35.2
(CCH3), 31.9 (CCH3) ppm. IR (KBr): ν˜ ϭ 2960, 2903, 2867
sized. This new family shares some of the peculiarities of
its phthalocyanine-related macrocycles, such as the nonaro-
matic nature of its free-base form and the aromaticity of
the metallated derivatives. However, metallotriazoleporphy-
razines may be considered as triazolephthalocyanine/por-
phyrazine hybrids, exhibiting absorptions in UV/Vis in the
same energy ranges as their similarly substituted porphyraz-
ines, this fact suggesting a similar degree of electronic de-
localization in the two systems. The simplicity of the char-
acterization of these compounds by standard spectroscopic (CϪH), 1609, 1501, 1462, 1445, 1362, 1342, 1269, 1137, 1109, 999,
Eur. J. Org. Chem. 2002, 2460Ϫ2464 2463

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M. K. Islyaikin, M. S. Rodrıguez-Morgade, T. Torres
FULL PAPER
956, 852, 838, 776, 767, 562 cmϪ1. UV/Vis (CH2Cl2): λmax (log ε) ϭ
250 (5.03), 325 (4.73), 374 (4.80), 472 (4.54), 579 (4.47), 602 nm
(4.50). MS (LSIMS, m-NBA): m/z ϭ 1165Ϫ1168 [Mϩ], [M ϩ H]ϩ.
C74H78N10Ni: calcd. C 76.2, H 6.7, N 12.0; found C 76.4, H 6.3,
N 12.1.
erials, (Ed.: H. R. Nalwa), Academic Press, New York, 2001,
pp.1Ϫ111.
M. S. Rodrıguez-Morgade, G. de la Torre, T. Torres in ЈЈDesign
and Synthesis of Low-Symmetry Phthalocyanines and Related
SystemsЈЈ, The Porphyrin Handbook, (Eds.: K. M. Kadish, K.
M. Smith, R. Guilard), Academic Press: San Diego, vol. 13,
in press.
[3]
[4]
´
(Triazoleporphyrazinato)copper(II) (7b): A mixture of 5 (44 mg,
0.04 mmol) and anhydrous Cu(OAc)2 (18 mg, 0.10 mmol) in DMF
(15 mL) was stirred at 100 °C for 6 h. After cooling to room tem-
perature, the reaction mixture was poured into water (100 mL) and
the resulting suspension was centrifuged. The precipitate was
washed with 1% ammonia solution, then with water, and finally
with MeOH. Column chromatography on silica gel with a 4:1 mix-
ture of hexane and dioxane afforded, after washing with hexanes,
37 mg (78%) of 7b as a dark red solid. IR (KBr): ν˜ ϭ 2966, 2956,
2904, (CϪH), 1609, 1461, 1364, 1330, 1269, 1109, 929, 846, 838,
564 cmϪ1. UV/Vis (CHCl3): λmax (log ε) ϭ 245 (4.83), 339 (4.66),
395 (4.74), 520 (4.48), 578 (4.40), 630 nm (4.44). MS (LSIMS, m-
NBA): m/z ϭ 1170Ϫ1173 [Mϩ], [M ϩ H]ϩ. C74H78N10Cu: calcd.
C 75.9, H 6.7, N 12.0; found C 76.3, H 6.4, N 12.2.
´
´
B. del Rey, U. Keller, T. Torres, G. Rojo, F. Agullo-Lopez, S.
´
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F. Fernandez-Lazaro, A. Sastre, T. Torres, J. Chem. Soc., Chem.
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´
´
´
(Triazoleporphyrazinato)cobalt(II) (7c): A mixture of 5 (44 mg,
0.04 mmol) and Co(OAc)2·4H2O (25 mg, 0.10 mmol) was heated at
100 °C in DMF (15 mL) for 6 h. The reaction mixture was allowed
to cool to room temperature and poured into water (100 mL). The
resulting suspension was centrifuged, and the precipitate was
washed with 1% ammonia solution, water, and MeOH to give 39 g
(82%) of a dark red solid. IR (KBr): ν˜ ϭ 2965, 2924, 2853, (CϪH),
1634, 1461, 1364, 1262, 1109, 1017, 997, 855, 838, 805 cmϪ1. UV/
Vis (CHCl3): λmax (log ε) ϭ 247 (5.04), 331 (4.81), 378 (4.91), 500
(4.62), 564 (4.56), 609 nm (4.61). MS (LSIMS, m-NBA): m/z ϭ
1166 [Mϩ], 1167 [M ϩ H]ϩ, 1168 [M ϩ 2 H]ϩ.C74H78N10Cu: calcd.
C 76.2, H 6.7, N 12.0; found C 76.4, H 6.6, N 11.7.
´
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´
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These protons have been detected for triazolephthalocyanines
at δ ϭ 10.3 ppm (see reference [14])
Similar chemical shifts have been observed for the inner isoin-
dole protons of cross-conjugated, nonaromatic hemiporphyraz-
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Acknowledgments
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This work was supported by CICYT, CAM (Spain), and the EU
through grants MAT99/0180, 07N/0051/2001 and HPRN-CT-
2000Ϫ0020, respectively. We also acknowledge the MEC (Spain)
and NATO for sabbatical research fellowships to M. K. I., and the
MEC for a research contract to M. S. R.-M.
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