Synthesis of tetra-silylated tetrathiafulvalene derivatives TTF(SiR2H)4 (RÂ =Â Me, Ph): Novel assembling ligands for the construction of bimetallic transition metal complexes

The HR2Si-functionalized tetrathiafulvalene (TTF) ligand TTF(SiR2H)4 (R = Me 2a; R = Ph 2b) have been synthesized and the molecular structure of 2a determined. The reactivity of the four Si-H bonds for oxidative addition reactions has been exploited. Thus, the bimetallic platinum-silicon complex [(PPh3)2Pt{(Me2Si)2TTF(SiMe2)2}Pt(PPh3)2] 3 incorporating TTF(SiMe2H)4 as bridging unit has been assembled by oxidative addition across [Pt(PPh3)2(CH2CH2)]. Electrochemical investigations by means of cyclic voltammetry reveals, for the complex 3, a strong cathodic shift of the two redox processes of the TTF core compared with those of 2a.