Silicon‐containing Schiff base and benzimidazole derivatives

Abstract

Abstract Investigations were undertaken to obtain information for use in the development of new heat‐stable polymers. Model silicon‐containing Schiff base and benzimidazole derivatives were synthesized by reaction of p ‐(triphenylsilyl)‐benzaldehyde with phenylenediamines. The structure and thermal stability of the products were studied. The reaction of p ‐(triphenylsilyl)benzaldehyde and o ‐phenylenediamine yielded N‐p ‐(triphenylsilyl)benzylidene‐ o ‐phenylenediamine which readily oxidizes to form 2‐ p ‐(triphenylsilyl)phenylbenzimidazole. The di‐Schiff bases, which most probably exist in trans‐trans configurations, were obtained from reaction of the aldehyde derivative with m ‐ and p ‐phenylenediamine. In contrast to similar Schiff bases without silicon, the products are soluble in organic solvents. The good resistance of the di‐Schiff base and benzimidazole derivatives to thermal decomposition suggests that polymers with repeating units of such structures would also be heat‐stable and might possess useful properties.