Cotton–Mouton effect, magnetizability anisotropy and molecular charge distribution of boron trichloride

Measurements of the magneto-optical Cotton–Mouton effect of gaseous BCl3 over a range of temperature (295.6–361.9 K) are analyzed in conjunction with the known electric polarizability anisotropy, mean magnetizability, molecular quadrupole moment and molecular geometry to obtain the magnetizability anisotropy (Δχ=χzz−χxx) and related magnetic properties (χzz, χxx, Δχd, Δχp, gzz−12gxx) of this species. The observation that Δχ is negative in sign is consistent with Paulingʹs view of the molecular structure in terms of pπ–pπ interactions, ionic–covalent resonance, partial double bond character and electron delocalization.