Polyterthiophene Appended by Organomolybdenum Sulfide Cluster:  Electrochemical Synthesis and Electrochemical Properties of Poly[Mo ₂ (μ-C ₅ H ₅ ) ₂ {μ-η ² :η ² -SC(R)C S[C ₄ HS(C ₄ H ₃ S-2) ₂ -2,5]} ₂ ]s

A series of monomeric clusters [(CpMo)2{SC(R)CS[C4HS(C4H3S-2)2-2,5]}2]s were prepared by the reaction of 3‘-(alkynyl)-2,2‘:5‘,2‘ ‘-terthiophenes with (CpMo)2(SC3H6S)2. The polymer hybrids prepared by the electropolymerization of the monomeric clusters show unusual electrochromism resulting from a synergistic interaction between the organomolybdenum sulfide cluster unit and the polythiophene π-backbone.