FT-IR investigation of CH center dot center dot center dot O and CH centerdot center dot center dot N hydrogen bonds in CHCl3+base systems in the middle infrared region

Two O-bases and one N-base were studied in chloroform as well as in deutero chloroform solutions. Moreover, methanesulfonic acid, dimethylphosphinic ac id, their tetrabutylammonium salts and their homoconjugated complexes were studied in an acetonitrile-chloroform mixture. The solutions were measured in the middle infrared region (MIR) at room temperature. The spectral data in the region of the stretching vibrations demonstrate the formation of CH ... O and CH ... N hydrogen bonds with relatively high stability. The inter action of chloroform with basic O-atoms and N-atoms is indicated by a broad ened and slightly bathochromically shifted nu(CH) vibration band. Furthermo re, a new transition at about 2500 cm(-1) was observed, being very characte ristic of hydrogen-bonded chloroform molecules. This new band is assigned t o the 2 delta(CH) vibration, intensified by Fermi resonance with the nu(CH) vibration. Obviously, the intensity of this band reflects the strength of the solvent interaction. This result is confirmed by results of the investi gation of two acids, their respective salts and their homo-conjugated compl exes. (C) 1999 Elsevier Science B.V. All rights reserved.