NEW CLASS OF PHOTOCHEMICALLY REACTIVE POLYMERS CONTAINING METAL-METAL BONDS ALONG THE POLYMER BACKBONE - SYNTHESIS, CHARACTERIZATION, AND REACTIVITY

A synthetic method was developed for incorporating metal-metal bonds into the backbones of polymers. The method involves the use of difunctional, cyclopentadienyl-substituted metal carbonyl dimers. Polyurethanes, polyureas, polyamides, and polyvinyls were synthesized in a demonstration of the new synthetic methodology. The polymers are photodegradable because the metal-metal bonds homolyze when irradiated with visible light. The photochemical reactions of the polymers in solution are essentially identical to the photochemical reactions of the discrete metal-metal bonded dimers. Typical reactions include metal-metal bond disproportionation and chlorine atom abstraction from carbon tetrachloride. The quantum yields for degradation in solution decrease as the molecular weight of the polymers increase. The polymers are also photochemically degradable in the solid state; thin films of the polymers degrade when irradiated with visible light in the presence of oxygen.