Spectrochemical and electrochemical studies of 21-thiatetra(p-tolyl)porphyrin and its copper(II) complexes

摘要: Abstract Electrochemistry, NMR, ESR and UV-Vis spectroscopy of 21-thiatetra( p -tolyl)porphyrin (STpTPH) respective copper(II) (21-tiatetra( -tolyl)porphyrin) X Cu(STpTP)X (X=Cl − , Br HCO 3 ClO 4 PPh ) complexes have been investigated. Monothiaporphyrin is an analogue widely studied tetraphenylporphyrin, where one the pyrrole rings has replaced by a thiophene moiety. The impact replacement coordinating abilities sulfur studied. STpTPH undergoes two step proton addition in dichloromethane. Mono- dication formations result distorting planar thiaporphyrin structure as confirmed NMR data. electronic spectra similar pattern to monocation form but pronounced dependence band positions on ligand character established. An spectrum typical for quasi-tetragonal Cu(II)systems. Parallel features show well resolved seven lines associated with coordination three nearly equivalent nitrogens. parameters, particularly hyperfine coupling constant A correlated geometry Cu(II) porphyrins or porphyrin- like ligands. influence axial parameters also discussed. Cyclic voltammetry studies that exhibits defined Cu(II)/Cu(I) reduction ( E 1/2 = −0.14 ±0.03 V depending ligand), reported previously only N-substituted not porphyrins. second results demetalation. physicochemcial properties are considerably different from Cu(TTP) closely resemble those porphyrin. Comparison between electrochemical spectroscopical discussed terms general stability Cu(II)-axial bond.