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(III)), [(TTDPz)M]-(H2O)(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 (v(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]-(H2O)(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 stare of the complexes has been achieved by Mossbauer 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.