Pressure and temperature dependences of 35Cl nuclear quadrupole resonances in p-chlorophenol

Abstract

The temperature and pressure dependence of the n.q.r. frequencies in α phase p-chlorophenol are reported. The temperature coefficients of the two resonances are equal within experimental error. The pressure coefficient (∂ν/∂P)T is less positive for the lower resonance than for the upper resonance. (∂ν/∂P)T also becomes smaller at high pressures, and at low temperatures becomes negative. The strong temperature dependence of (∂ν/∂P)T suggests that any theory of intermolecular effects on n.q.r. frequencies should be tested against the value of (∂ν/∂P)T at 0 K rather than at room temperature.