Dihydrogen bonded phenol–borane-dimethylamine complex: An experimental and theoretical study.

Continuing with our earlier communication on the dihydrogen bonded phenol-borane-dimethylamine complex [J. Chem. Phys. 113, 9885 (2000)], we report here, the realistic structure of the said complex calculated using density functional theory at B3LYP/6-31 + + G(d,p) level. The agreement between the experimental and calculated vibrational spectrum for both the N-H and O-H stretching vibrations along with the low-frequency vibrations that appear in combination with O-H stretching, provides the basis for structural assignment. Analysis of the fate of B-H bonds and B-H stretching vibrations upon formation of dihydrogen bond reveals an anomalous behavior of average bond strengthening. [ABSTRACT FROM AUTHOR]