Zeeman Quadrupole Spectra of p-Chloroaniline and p-Chlorobenzylchloride

Abstract

Analysis of the Zeemanquadrupolespectra of Cl35 in single crystals of p‐chloroaniline and p‐chlorobenzylchloride yields the following information: There are two sets of chlorine atoms in the p‐chloroaniline crystal with differently oriented electrical field gradients. The angle between the field gradient z‐axes is 79°±1°; the y‐axes are parallel. Both field gradients have the same asymmetry, η=0.06±0.03. In p‐chlorobenzylchloride there are four sets of chlorines (attached directly to the ring) which have differently oriented field gradients. The z‐axes are parallel to the edges of a rectangular pyramid with apex angles of 8° and 67°, both ±1°. All four have the same asymmetry, η=0.07±0.02. The bond between the chlorine and the ring is calculated to have 2.0±1.0% double bond, 79±10% single bond and 19±10% ionic character in p‐chloroaniline; 2.4±0.7% double bond, 80±10% single bond and 17±10% ionic character in p‐chlorobenzylchloride. The large uncertainty in the single bond and ionic characters results from the uncertainty in the hybridization of the chlorine bonding orbital.