2ND-ORDER QUADRUPOLAR EFFECTS FOR DIRECTLY BONDED AND REMOTE C-13-BR-79 81 SPIN PAIRS IN HIGH-RESOLUTION C-13 NMR-SPECTRA OF SOLIDS/

High-resolution solid-state C-13 NMR spectra of 1,4-dibromobenzene, 1, 3,5-tribromobenzene, 1,2,4,5-tetrabromobenzene and hexabromobenzene (r ecorded at several different magnetic field strengths from 4.7-14.1 T) are reported. The bandshapes for C-13 nuclei directly bonded to Br-79 /81 nuclei are characteristic multiplets arising from the effects of s econd-order quadrupolar interactions and both direct and indirect dipo le-dipole interactions between C-13 and Br-79/81. Numerical simulation s have been used to obtain data on dipolar coupling constants and/or a nisotropies in indirect coupling. In these simulations, effects arisin g from interaction with the directly bonded Br-79/81 nucleus, intramol ecular interactions with Br-79/81 nuclei in the ortho, meta and para p ositions relative to the C-13 nucleus, and intermolecular interactions with Br-79/81 nuclei in neighbouring molecules were considered. Spect ra are also presented for a range of other organic solids containing b romine.