Cooperative hydrogen bonding in solution: Influence of molecule structure

Influence of cooperative interactions on IR stretching vibration frequencies of complexes CCl3H⋯ROH⋯B (B-base), CCl3H⋯ROH⋯O(C2H5)2 and CCl3H⋯ROH⋯ROH in proton donor solvent CCl3H were studied.Solvent effects on OH stretching vibration frequencies of CF3CH2OH⋯B, ROH⋯O(C2H5)2 and ROH⋯ROH complexes in aprotic solvents were calculated using earlier proposed method. Cooperativity factors in CCl3H⋯CF3CH2OH⋯B complexes were determined. Obtained values were significant smaller than for CCl3H⋯CH3OH⋯B complexes. Also cooperativity factors for CCl3H⋯ROH⋯O(C2H5)2 and CCl3H⋯ROH⋯ROH complexes were determined. It was demonstrated that obtained values slightly depend on length and embranchment of alkyl group in alcohol molecules. The main role in cooperative interactions plays electronic effect.