Thienyl carboxylate ligands bound to and bridging MM quadruple bonds, M=Mo or W: Models for polythiophenes incorporating MM quadruple bonds

The synthesis of a series of compounds are made where M-Mo or W, L = a thienyl, or terthienyl carboxylate, and L are corresponding thienyl dicarboxylate. The electronic absorption spectra are reported and show intense metal-to-ligand charge transfer bands.