Temperature dependence of17O and14N NQR frequencies in commercial TNT

The temperature dependence of the17O nuclear quadrupole resonance (NQR) frequencies has been measured in commercial trinitrotoluene by highly sensitive nuclear quadrupole double resonance techniques. The14N NQR frequencies have been measured in the same sample for comparison. In contrast to the14N quadrupole coupling constant, the17O quadrupole constant increases with increasing temperature.