Infrared spectra and structure of butyldimethylammonium dicyanomethylide: an ab initio force field treatment

The structure of butyldimethylammonium dicyanomethylide has been studied on the basis of both infrared spectra and ab initio force field calculations. The 3031-416 cm(-1) region bands have been assigned; a good agreement has been found between the theoretical and experimental spectroscopic characteristics. According to both infrared data and bond parameters, the dicyanomethide group in the molecule studied has a pronounced anionic character. However the analysis of the net atomic charges indicates at an only moderate (0.45 e(-)) charge transfer between the ammonium and the dicyanomethide fragments of the butyldimethylammonium dicyanomethylide molecule. (C) 1997 Elsevier Science B.V.