The new macrocycle tetrakis(thiadiazole)porphyrazine, TTDPzH 2 , has been prepared, in CF 3 COOH, from its corresponding Mg(II) derivative, [TTDPzMg(H 2 O)]‚CH 3 COOH, which, in turn, is obtained by the reaction of magnesium(II) propylate and 3,4-dicyano-1,2,5-thiadiazole. The Mg(II) complex is also used for the preparation of the Cu(II) derivative, TTDPzCu, by reaction with copper acetate in CF 3 COOH. An alternative preparation allows the Cu(II) complex to be obtained from the metal-free macrocycle and Cu(OCOCH 3 ) 2 in pyridine. Like the Mg(II) complex, TTDPzH 2 and TTDPzCu are obtained as solvated species (carboxylic acid, water). Practically complete elimination of the solvent molecules can be achieved by heating the species under vacuum (10 -2 mmHg) at 300-310°C, only the Mg(II) complex retaining water. TTDPzH 2 and TTDPzCu can also be obtained by sublimation under vacuum (10 -2 mmHg, 400-450°C) from the parent solvated complexes. IR spectra in the range 4000-200 cm -1 allow easy identification of the different species. Deuteration of TTDPzH 2 has allowed assignments of the NH stretching and bending vibrations. The UV-visible solution spectra in different media all exhibit intense absorptions in the Soret-band (300-400 nm) and Q-band (600-700 nm) regions, showing strong resemblance to those of their corresponding phthalocyanine analogues. A detailed analysis of the spectral behavior allows the electronic structure of the TTDPz macrocyclic ring to be adequately depicted. IntroductionSome of the most recent research work on the synthesis, chemical-physical characterization, and reactivity of metal phthalocyanines developed by our and joint laboratories has shown the capacity of different diphthalocyanine molecular units, i.e., Pc 2 M (M ) Ti(IV), Sn(IV)), 1 (PcFe) 2 C, 2 and (PcRu) 2 , 3 to result in the formation of linearly elongated electrically conductive materials upon oxidation with I 2 or O 2 , and the role played by the metal centers and by the close π-π contacts of the adjacent Pc rings in the efficiency of charge transfer along the chained systems has been thoroughly examined. 1-3 We have now started an investigation on porphyrazine (Chart 1a) and substituted porphyrazines and their metal derivatives, a class of materials far less studied, though recently the object of growing interest, 4 than their closely related phthalocyanine 5 (Chart 1b) and porphyrin analogues, 6 and have focused our attention on the synthesis of tetrakis(thiadiazole)porphyrazine, TTDPzH 2 (Chart 2a) and its selenium analogue and their metal derivatives as well, because electron-rich and soft substituents such as S or Se inserted into the proximity of the central

The new phthalocyanine-like macrocycle tetrakis(selenodiazole)porphyrazine, TSeDPzH 2, and its Mg ( II ) and Cu ( II ) complexes have been prepared and their general, spectroscopic (IR, UV-vis), and magnetic properties investigated. It has been observed that the peripheral selenodiazole rings of the TSeDPz skeleton can be opened by the action of H 2 S , with release of the Se atoms and formation of a new macrocycle, i.e. octaaminoporphyrazine, which is easily converted into tetrakis(pyrazino)porphyrazine derivatives.

The synthesis and general chemical physical characterization of the following new classes of complexes derived from tetrakis(thiadiazole)porphyrazine (TTDPzH(2)), i.e., [(TTDPz)M(DMSO)(2)] (M = Mn(II), Fe(II)), [(TTDPz)M](H(2)O)(2), and [(TTDPz)M] (M = Mn(II), Fe(II), Co(II), Ni(II), Zn(II)) are reported. The IR spectra in the region 4000-200 cm(-)(1) show for all the species typical modes of the TTDPz skeleton and specific absorptions of the thiadiazole ring. The UV-visible spectra in different media show the expected absorptions in the Soret and Q-band regions. Inspection of the IR spectra of the two six-coordinate adducts [(TTDPz)M(DMSO)(2)] and of their corresponding species containing DMSO-d(6) clearly indicate that DMSO is O-bonded to the central metal in both species (nu(SO) located at 918 and 940 cm(-)(1) for the Fe(II) and Mn(II) species, respectively), differently from the findings for DMSO (S-bonded) in the Fe(II) and Ru(II) phthalocyanine analogues. The complexes [(TTDPz)M](H(2)O)(2) and [(TTDPz)M] are all tetracoordinate species, the water molecules for the hydrated species being very likely only weakly ligated at the peripheral thiadiazole rings of the macrocycle. Some additional information on the oxidation and spin state of the complexes has been achieved by Mössbauer spectra (Fe) and room-temperature magnetic susceptibility measurements, and data at hand are compared, when allowed, with those of the parallel classes of metal phthalocyanine complexes.

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