Electronic structure of platinum-containing polyynes

Using an Extended Hückel approach, we investigate the electronic structure of a class of metal-containing polyynes (oligomers and polymers). These systems contain square-planar coordinated platinum sites linked by conjugated sequences of acetylenic units. We mainly focus on the evolution of the first optical transition as a function of the molecule size when going from short oligomers to the polymer. Our primary interest is in establishing the contribution of the metal atoms in the conjugation path.