Je. Huyett et al., PULSED ENDOR AND ESEEM STUDY OF [BIS(MALEONITRILEDITHIOLATO)NICKEL](-) - AN INVESTIGATION INTO THE LIGAND ELECTRONIC-STRUCTURE, Inorganic chemistry, 37(6), 1998, pp. 1361-1367
By a combination of Q-band pulsed ENDOR (electron nuclear double reson
ance) and X-band ESEEM (electron stimulated echo envelope modulation)
techniques, we have determined the hyperfine tensors for ethylene (C1)
and cyano (C2) carbons and N, of [Ni(mnt)(2)](-), along with the quad
rupole tensor for nitrogen. These measurements give it electron spin d
ensities of rho(C1) similar to 0.03 in the C1 2p(z) orbital, rho(C2) <
0.003, rho(N) similar to 0.01, such that in total, similar to 0.15 of
the spin resides on the ligand atoms C and N, while the rest resides
in the NiS4 core, giving rho(NiS4-) = 0.85. These results are compared
with extended Huckel and density functional (BLYP) MO calculations, a
s well as with X alpha calculations reported earlier.