Paramagnetic properties of covalently linked mixed valence chromium complexes in polymers

摘要

Chromium complexes, where ortho-quinone ligands are covalently linked to polymeric chains of polyethylene, polystyrene, and copolymer of ethylene and vinylacetate are studied. The results of infrared and electron paramagnetic resonance spectroscopic studies of chromium coordination polymers show that covalent linking of quinone ligands is accompanied by the change in the valence states of chromium Cr(III)reversibleCr(IV)reversibleCr(V). The ligand field of the triplet Cr~(4+) ion is close to the one in Cr-doped Y_(2)SiO_(5), a laser material in the visible and infrared regions. Therefore some useful magnetic and/or optical properties in such transition metal coordination polymers can be expected.