The structure of solid copper(I) cyanide: A multinuclear magnetic and quadrupole resonance study

Carbon-13 and nitrogen-15 nuclear magnetic resonance (NMR) spectra of solid copper(I) cyanide present a clear picture of its molecular structure as comprising linear, polymeric chains: [-CU-N-C-](n). Copper-63/65 nuclear quadrupole resonance reveals that the cyanide ligands are subject to "head-tail" disorder. Magic-angle spinning NMR spectra an, analyzed by accounting far the quadrupalar effects of neighboring copper nuclei: to yield one-bond indirect spin-spin coupling constants, (1)J(Cu-63,C-13) approximate to +725 Hz and (1)J(Cu-63,N-15) approximate to -250 Hz, and effective dipolar coupling constants, R-eff(Cu-63,C-13) approximate to +1200 Hz and R-eff(Cu-63,N-15) approximate to -460 Hz, The dipolar coupling data correspond to internuclear separations of r(Cu,C) approximate to 1.88 Angstrom and r(Cu,N) approximate to 1.92 Angstrom. The observation of axially symmetric N-15 and C-13 chemical shielding tensors in NMR spectra of nonspinning samples. provides compelling evidence for the structural linearity of CuCN chains. Conclusions based on experimental data are supported by ab initio calculations of chemical shielding and electric field gradients.