Molecular Quadrupole Moments, Magnetic Anisotropies, and Charge Distributions of Borazine, B-Trichloroborazine, N-Trimethylborazine, and B-Trichloro-N-trimethylborazine. Comparison with Benzene and Its Derivatives.

Article abstract of DOI:10.1021/j100134a008

Measurements of the dilute-solution molar Kerr constants, field-gradient birefringence constants, and Cotton-Mouton constants of borazine and three substituted borazines as solutes in cyclohexane or carbon tetrachloride at 25 deg C are reported.The observations yield the first direct experimental values of the effective polarizability anisotropies, electric quadrupole moments, and magnetic anisotropies, which are important descriptors of the molecular charge distributions.A comparison of the results for borazine with literature data for benzene shows that all three properties have the same signs in the two species but that all are considerably smaller in magnitude in borazine than in benzene.An analysis of the magnetizabilities indicates that the extent of electron delocalization in borazine is only about one-third of that in benzene, a conclusion which is consistent with a range of other evidence.