Stepwise synthesis of peripherally dimetallated metallo-tetraazaporphyrins with linear and bent motifs

Abstract

Two new dinuclear and two new trinuclear complexes of 2, 3,7,8,12,13,17,18-octakis(methylthio)tetraazaporphyrinatomagnesium(II), [Mg(OMTTAP)] were synthesized using a convenient stepwise process. These complexes possess (bpy) 2 Ru II and Cp(PPh 3 )Ru II metal moieties directly attached to the b-positions in the [Mg(OMTTAP)] through thioether chelation. Complexes were characterized using 1 H-n.m.r., u.v.-vis and mass spectroscopic data. The peripheral binding of the two Ru II units significantly influenced redox potentials of the OMTTAP core by lowering E 1/2 for the OMTTAP centered oxidation and reduction processes, both, as evident from their cyclic voltammograms. The stepwise synthesis reported here demonstrates success of a convenient strategy to obtain hybrid, trimetallic, redox active chromophores with linear and bent motifs.