THE MICROWAVE SPECTRUM AND ELECTRONIC STRUCTURE OF ARSABENZENE

Author Institution: Department of Chemistry, University of MichiganThe ground vibrational state of arsabenzene $(C_{5}H_{5}A_{s})$ was studied. Rotational constants are $A = 4871.03 + 0.18$ MHz, $B = 2295.87 \pm 0.01$ MHz, and $C = 1560.10 \pm 0.01$ MHz. The small inertial defect (0.08 amu-{\AA}$^{2}$) is consistent with a planar structure. Arsenic quadrupole coupling constants were determined as $X_{aa} = - 186.4 \pm 0.1$ MHz, $X_{bb} = 43.5 \pm 0.2$ MHz, and $X_{cc} = 142.9 \pm 0.2$ MHz. The molecular dipole moment was measured as 1.09 $\pm$ 0.02 D. The quadrupole data was analyzed in terms of a simple $\sigma$ $\Pi$ model with $\sigma$ and $\Pi$ bonds to arsenic