Solid-state 115In NMR study of indium coordination complexes

Abstract

The feasibility of solid-state ¹¹⁵In NMR studies is demonstrated by an examination of four different coordination complexes: indium(III) acetylacetonate, indium(III) tris(tropolonato), indium(III) triiodide bis(tris(4-methoxyphenyl)phosphine oxide) and indium(III) trichloride tris(2,4,6-trimethoxyphenyl)phosphine. The results provide information about the electric field gradients and magnetic shielding at the indium nuclei through the nuclear quadrupolar and chemical shift parameters, respectively. The C_Q values in these four complexes range between 106.0 ± 2.0 and 200.0 ± 4.0 MHz, while the magnetic shielding anisotropies fall in the range from 85 ± 15 to 550 ± 60 ppm. Finally, this research demonstrates that solid-state ¹¹⁵In NMR studies are facilitated by performing experiments at the highest possible magnetic-field strengths, and that NMR offers a promising tool for the characterization of indium compounds.