TIN PORPHYRINS .6. SN-119 CHEMICAL-SHIFTS AND LINE WIDTHS OF TIN(IV) COMPLEXES OF TETRAPHENYLPORPHYRIN, TETRA-P-TOLYLPORPHYRIN, AND OCTAETHYLPORPHYRIN

Tin-119 NMR spectra are reported for chloroform solutions of PSnX2 [P = dianion of 5,10,15,20-tetraphenylporphyrin (TPP), X = CF3SO3-, ClO4-, NO3-, CF3CO2-, Cl2CHCO2-, (o-OH)C6H4CO2-, HCO2-, C6H5CO2-, CH3CO2-, (p-NO2)C6H4O-, (p-Br)C6H4O-, (p-CH3)C6H4O-, HO-, CH3O-, F-, Cl-, Br-, I-; P = dianion of 5,10,15,20-tetra-p-tolylporphyrin (TTP), X = HCO2-, HO-, Cl-; P = dianion of 2,3,7,8,12,13,17,18-octaethylporphyrin (OEP), X = HO-, Cl-]. For the complexes of O-bound axial ligands, stronger donors generally shift the Sn-119 resonance downfield, while for the carboxylates (apart from HCO2-) the reverse is the case. The nature of the porphyrin ligand has little effect on delta(Sn), for the same axial ligands. For the TPP series, and excluding the halides, the widths at half-height of the Sn-119 signals are dependent on the nature of the axial anions. These line widths correlate (r = 0.968) with the coupling constants between the tin nucleus and protons on the pyrrole beta carbons, suggesting that these parameters are reflecting the cis-influences of the axial ligands on the Sn-N bonds. The spectra of the halide complexes display more complex behavior.