Building block ligands for new molecular conductors: homobimetallic tetrathiafulvalene tetrathiolates and metal diselenolenes and ditellurolenes

Abstract

Important building block ligands such as 2-thioxo-1,3-dithiole-4,5-dithiolate (dmit) and ethene-1,2-dithiolate (thiolene) form metal complexes that have been found to exhibit metallic conductivity and superconductivity. The syntheses of three well defined building block ligands that can lead to new molecular conductors and the synthesis and characterization of four new metal complexes of these ligands are presented. The ligands are tetrathiafulvalene tetrathiolate (2), ethene-1,2-diselenolate (9)(diselenolene) and ethene-1,2-ditellurolate (6)(ditellurolene); the metal complexes are a Ti complex, (PrⁱC₅H₄)₂Ti[S₂TTFS₂]Ti(PrⁱC₅H₄)²·1.5C₆H₆(3), an Ni complex, (dppp)Ni[S₂TTFS₂]Ni(dppp)(4), a Pt–diselenolene complex, Pt(Se₂C₂H₂)(PPh₃)₂(10) and a Pt–ditellurolene complex Pt(Te₂C₂H₂)(PPh₃)₂(8). The X-ray crystal structure of (PrⁱC₅H₄)₂Ti[S₂TTFS₂]Ti(PrⁱC₅H₄)₂·1.5C₆H₆(3) and its interesting chain-link fence crystal packing are also presented. These ligands represent opportunities to produce a whole new class of molecular conductors.