Electroactive, Near Infrared Absorbing Nickel Bis(dithiolene) ComplexPolycarbonates and Polyurethanes

摘要

A new series of polycarbonates and polyurethanes, containing nickelbis(dithiolene) (Ni-BDT) complexes in the main chain, have been synthesized via polymerization of a functionalized Ni-BDT complex. These polymers are highly soluble in common organic solvents, and free-standing films can be cast from solution. Gel permeation chromatographic analysis on these polymers indicates hydrodynamic volumes comparable to polystyrene standards having weight average molecular weights (Mw) ranging from 1.35 x 10 to the fourth power to 9.8 x 10 to the fourth power. These polymers exhibit a near-IR absorbance between 830-940 nm in solution due to the Ni-BDT complex and solvatochromism is observed with more polar solvents shifting the near-IR absorbance band to higher wavelength. A single glass transition (Tg) is observed for all polymers, suggesting a relatively random polymerization (no phase separation). The Tg's of the polycarbonates decrease with increased Ni-BDT, while the Tg's of the polyurethanes increase, as expected for changes in chain rigidity. Most of the Ni-BDT complex polymers are electroactive with a two step redox process, typical for Ni-BDT complexes, observed in cyclic voltammograms of the polymers in solution. The results presented herein indicate that the incorporation of Ni-BDT complexes into polymer main chains impart the unique optoelectronic properties of Ni-BDT's to the polymer.