Temperature Dependence of Chlorine NQR Frequencies and Pi Bonding

摘要

A theory is presented for the anomalous temperature dependence of35Cl NQR frequencies observed for certain transitionhyphen;metalmdash;chloride compounds. The basic feature of the theory is a break down of pgr; bonding due to bending vibrations, and a consequent increase in the electron population in chlorine 2ppgr; orbitals, causing in turn an increase in the observed NQR frequency. An approximate separation of latticehyphen;motion effects and intramolecular effects is made for the series of compounds K2MCl6, M = W, Re, Os, Ir, Pt, and it is shown that the predicted magnitude and behavior of the intramolecular effects agree well with the observed values.