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7952660 
Journal Article 
NMR AND RAMAN-SPECTROSCOPIC STUDY OF CDCL3 IN CYCLOHEXANE SOLUTIONS IN THE PRESENCE OF PYRIDINE, QUINUCLIDINE OR TRIETHYLAMINE 
Bagley, S; Kowalewski, J; Sandstrom, M 
1992 
Yes 
Journal of Molecular Liquids
ISSN: 0167-7322 
54 
1-3 
89-101 
English 
WOS:A1992JW86600014 
NMR and Raman spectroscopic methods have been used to study deuterated chloroform (ca. 10 mol%) with added pyridine (py), quinuclidine (Q) or triethylamine (Et3N) (0 - ca. 15 mol%) in cyclohexane solutions. In the Raman spectra of the CDCl3 solutions new bands shifted to lower wavenumbers appear for the CCl and CD stretching vibrations when the above N-donor Lewis bases are added. These bands age ascribed to the formation of 1:1 hydrogen bonded complexes with CDCl3. A quantitative evaluation of the band areas, using the breathing mode of cyclohexane as internal standard, allowed relative molar scattering coefficients to he evaluated for the displaced CCl bands of the CDCl3 hydrogen bonded species by fitting calculated to experimental concentrations. Equilibrium constants were then obtained for the 1:1 complex formations CDCl3 + N-donor ⇌ CDCl3·N-donor: Kpy = 0.8 ± 0.2, KQ = 0.8 ± 0.2, and KEt3N = 0.53 ± 0.05 dm3 mol-1. The NMR relaxation times of 2D and 35Cl for CDCl3 have been measured and analyzed in terms of anisotropic rotational diffusion, in addition the perpendicular rotational diffusion constant of CDCl3 in cyclohexane has been estimated from the Raman CD stretching band widths. Using the concentrations of the free and hydrogen bonded CDCl3 species from the Raman experiment the rotational correlation times for the CDCl3·N-donor complexes have been obtained. 1992.