METALLOPORPHYRINS CONTAINING SIGMA-BONDED NITROGEN AXIAL LIGANDS .1. SYNTHESIS AND CHARACTERIZATION OF INDIUM(III) PORPHYRIN COMPLEXES - MOLECULAR-STRUCTURES OF (4-PHENYLTETRAZOLATO)(2,3,7,8,12,13,17,18-OCTAETHYLPORPHINATO)INDIUM(III) AND (5-METHYLTETRAZOLATO)(2,3,7,8,12,13,17,18-OCTAETHYLPORPHINATO)INDIUM(III)

The synthesis and characterization of 16 nitrogen sigma-bonded (tetrazolato)- and (triazolato)indium(III) porphyrin complexes are reported. Each metalloporphyrin was characterized by UV-visible, IR, and H-1 NMR spectroscopy as well as by electrochemistry. The molecular structure of (OEP)In[N4C(CH3)] was solved and compared to (OEP)In[N4C(C6H5)], whose characterization was reported in a preliminary communication. (OEP)In[N4C(CH3)] crystallizes in the triclinic system, space group P-1BAR (a = 12.035 (2) angstrom, b = 12.855 (2) angstrom, c = 14.097 (3) angstrom, alpha = 110.00 (3)-degrees, beta = 111.10 (3)-degrees, gamma = 90.52 (3)-degrees, Z = 2, rho = 1.265 g cm-3, R(F) = 5.13%). The tetrazolato group of (OEP)In]N4C(CH3)[ is substituted at the 5-position of the axial ligand, whereas the C6H5 group of (OEP)In[N4C(C6H5)] is substituted in the 4-position of the tetrazolato ligand. The spectroscopic data suggest that the tetrazole or triazole linkage mode depends upon the nature of the aryl or alkyl group attached to the axial ligand, and this was confirmed by structural data for two of the complexes.