Nuclear quadrupole resonance studies of boron–chlorine compounds. Part I. Boron trichloride and the phenylboron chlorides

Abstract

The asymmetry parameters of the ³⁵Cl nuclear quadrupole resonance spectra of boron trichloride and phenylboron dichloride have been measured on polycrystalline samples by the method of Morino and Toyama. The value of 0·54 ± 0·02 in boron trichloride is consistent with recent molecular orbital calculations on the boron trihalides and the π-bonding order Bl₃ > BBr₃≃ BCl₃. The extent of s-hybridization of the σ bonding orbitals as estimated by an extension of the SGOBE method is found to be unreasonably high.