Conversion of site-specific deuterated closo-1,2- and 1,7-C 2 B 1 0 H 1 2 to deuterated nido-7,8- and 7,9-[C 2 B 9 H 1 2 ] - ions, respectively; mechanistic inferences. Comparisons of GIAO-NMR generated [C 2 B 9 H 1 2 ] - chemical shifts with experimental values, and consideration of two principal isomers of the 7,8-[C 2 B 9 H 1 2 ] - ion by comparison of geometry optimization data, NMR chemical shift data, and NMR coupling data to respective experimental data