Reaction of Cu(1,2-phenylenediamine)2(ClO4) 2 with neat RR'=O (R = methyl and/or ethyl) gives Cu(2,2-dialkyl-2H-benzimidazole)ClO4, demetallation of which by the action of aqueous ammonia yields pure 2,2-dialkyl-2H-benzimidazoles. These are characterised by NMR. In the X-ray crystal structure, Ag(2,2-methyl-2H-benzimi- dazole)NO3 is found to be a spiral ID coordination polymer where the 2H-benzimidazole acts as an N,N bridge between two Ag(I) centers. Although 2H-benzimidazoles are very unstable in the free stale, they are quite stable in their Cu(I) and Ag(I) complexes. The 1,2-tautomerisation in imidazole and benzimidazole have been studied by means of transition state calculations at B3LYP/6-3H+G(2d,p)* level.
|Number of pages||5|
|Journal||Indian Journal of Chemistry - Section A Inorganic, Physical, Theoretical and Analytical Chemistry|
|State||Published - Nov 2007|