N,N′-Linked 1,2-ethanediyl-poly(benzimidazolin-2-ones) and the X-ray crystal structure of a benzimidazolin-2-one trimer

A series of N,N′-linked 1,2-ethanediyl-poly(benzimidazolin-2-ones) that can be classified as podands, are described. Seven dimers (21–27), three trimers (28–30), a cyclic tetramer (31) and an open-chain benzimidazolin-2-one heptamer (32) have been prepared and characterized by 1H, 13C NMR and by MS. The crystal and molecular structure of the trimer, 1,3-bis-2-(2-oxobenzimidazol-1-yl)ethyl-2-oxobenzimidazole monohydrate (30) has been solved by X-Ray analysis. The benzi-midazolin-2-one fragments display a pattern of bond distances and angles similar to that of analogue derivatives retrieved form the CSD. The molecules are hydrogen bonded to four others in a continuous two-dimensional network by NH…OC and CH…OC interactions in which all NH donors and OC acceptors are involved.