Determination of magnetic and structural properties in solids containing antiferromagnetically coupled metal centers using NMR methods. Magneto−structural correlations in anhydrous copper(II) n-butyrate

摘要: A new approach to the investigation of magneto-structural correlations in solids containing antiferromagnetically coupled transition-metal centers is described that illustrates potential NMR spectroscopy such work. The results a variable-temperature (VT) /sup 13/C cross-polarization magic-angle-spinning (CP/MAS) anhydrous copper(II) n-butyrate, (Cu(C/sub 3/H/sub 7/COO)/sub 2/)/sub 2/ are reported. Isotropic shifts found be primarily contact origin, and statistical analysis their temperature dependence allows calculation singlet-triplet energy level separations (-2J), diamagnetic (delta/sub dia/), electron-nucleus hyperfine coupling constants (A), which shown give insight into mechanisms electron delocalization along superexchange pathway. Signal multiplicity can related compound structure, was determined by using x-ray crystallography. title triclinic has space group P/anti 1/ with = 9.035 (2) /angstrom/, b 5.192 c 11.695 (3) ..cap alpha.. 85.88 (2)/degrees/, ..gamma.. 109.32 Z 1, V 515.2 /angstrom//sup 3/; final weighted R value for 2169 reflections 0.048. 21 references, 4 figures, tables.