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 co mprising linear, polymeric chains: [-CU-N-C-](n). Copper-63/65 nuclear quad rupole 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 in direct spin-spin coupling constants, (1)J(Cu-63,C-13) approximate to +725 H z and (1)J(Cu-63,N-15) approximate to -250 Hz, and effective dipolar coupli ng constants, R-eff(Cu-63,C-13) approximate to +1200 Hz and R-eff(Cu-63,N-1 5) approximate to -460 Hz, The dipolar coupling data correspond to internuc lear separations of r(Cu,C) approximate to 1.88 Angstrom and r(Cu,N) approx imate 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. Conclusion s based on experimental data are supported by ab initio calculations of che mical shielding and electric field gradients.