The deuterium quadrupole coupling constant in liquid ammonia

Abstract

The presence of hydrogen bonds in liquid ammonia is not without controversy. Probes for hydrogen bonds are the gas to liquid shift and the temperature dependence in the liquid of the deuterium quadrupole coupling constant (DQCC). Using a new NMR method, the first reliable results for the DQCC in liquid heavy ammonia were obtained for six temperatures between 237 and 293 K. The value of 232(1) kHz at 237 K amounts to only 80% of the gas phase value. A small temperature dependence of about 0.1 kHz K⁻¹ in the liquid is observed. These results support the hypothesis that hydrogen bonds play an important role in liquid ammonia, similar to the situation in water.