Polymeric carbodiimides as precursors for ceramic materials: Reaction mechanisms and tautomerism

Abstract

The reaction mechanisms for the synthesis of polymeric silicon and titanium carbodiimides via the element chlorides and bis(trimethylsilyl)-carbodiimid, used as precursors for ceramic materials, have beer, investigated using quantumchemical methods. The influence of organic bases as catalysts on the transition state and the thermodynamics of the reaction are discussed. The ratio of the tautomers carbodiimid - cyanamid depending on the heteroatom, the solvent and the temperature, has been determined using ab-initio methods (density functional theory). The results of the theoretical calculations are confirmed by IR and UV spectroscopic data.