Synthesis and physicochemical characteristics of alkane (or arene)-thio-, -sulphinato-, and -sulphonato-indium(III) porphyrins. Crystal structure of methanesulphonato(5,10,15,20-tetraphenylporphyrinato)indium(III)

Abstract

Indium(III) porphyrins containing metal–sulphur bonds [InL(SR)](L = porphyrinate, R = alkyl or aryl) are reported. The photochemical oxidation of these leads to the corresponding sulphinatoindium(III) porphyrins [InL(SO₂R)]. The insertion of sulphur dioxide between the indium atom and the alkyl or aryl group of [InL(R)] also gives rise to the sulphinato-compounds. The latter can easily be oxidised to the corresponding sulphonato-complexes. The crystal structure of the title compound [In(tpp)(SO₃CH₃)]·2C₂H₄Cl₂ has been determined by X-ray diffraction methods. Crystals are triclinic, space group P, with a= 13.027(2), b= 13.284(2), c= 14.029(2)Å, α= 68.82(2)°, β= 85.31(2)°, γ= 88.13(2)°, and Z= 2. The structure has been solved by Patterson and Fourier methods and refined by full-matrix least-squares calculations to R= 0.063. This complex crystallises as a one-dimensional polymer, parallel to the c axis. The indium atom lies rigorously in the four-nitrogen plane and the structure may be described as the close packing of [In(tpp)]⁺ and [SO₃CH₃]^– ions. A high-resolution n.m.r. study shows that this structure is destroyed in solution at low concentrations.