Experimental gas-phase halogen nuclear quadrupole coupling constants; A review

As a preclude to a theoretical study of nuclear quadrupole coupling constants (NQCC), via the electric field gradients at equilibrium, we review the current stare of knowledge of gas-phase data for a diverse set of axially symmetric inorganic and organic molecules with symmetries C-3 nu, C-infinity nu, D-infinity h in particular, where the heavy elements are Cl, Br and I with C, Si and Ge hydrides. In most of the cases, the latter elements are in an approximately tetrahedral environment.