SYNTHESIS, MOLECULAR-STRUCTURE AND ELECTROCHEMICAL INVESTIGATION OF THE 1,2,5-THIADIAZOLE-3,4-DITHIOLATE-SUBSTITUTED COMPLEX CP-ASTERISK-RU(NO)(TDAS) - EVIDENCE FOR NITROSYL BENDING DURING REDUCTION
Cg. Xia et al., SYNTHESIS, MOLECULAR-STRUCTURE AND ELECTROCHEMICAL INVESTIGATION OF THE 1,2,5-THIADIAZOLE-3,4-DITHIOLATE-SUBSTITUTED COMPLEX CP-ASTERISK-RU(NO)(TDAS) - EVIDENCE FOR NITROSYL BENDING DURING REDUCTION, Inorganica Chimica Acta, 226(1-2), 1994, pp. 267-274
Treatment of disodium 1,2,5-thiadiazole-3,4-dithiol (Na(2)tdas) with t
he cyclopentadienyl complex CpRu(NO)Cl-2 in MeOH gives the correspond
ing 1,2,5-thiadiazole-3,4-dithiolate-substituted complex CpRu(NO)(tda
s) in 61% yield. The product has been characterized in solution by IR
and NMR (H-1 and C-13) spectroscopies, and the molecular structure of
CpRu(NO)(tdas) has been established by X-ray diffraction analysis. Cp
Ru(NO)(tdas) crystallizes in the monoclinic space group P2(1)/c with
a=26.204(2), b=8.4915(6), c=14.2339(9) Angstrom, beta=90.739(5)degrees
, V=3166.9(3) Angstrom(3) and Z=8. Full-matrix least-squares refinemen
t yielded R=0.0338 for 3151 (I>3 sigma(I)) reflections. The redox prop
erties of CpRu(NO)(tdas) were examined by cyclic and rotating disk el
ectrode voltammetric techniques. Two electrochemical responses were ob
served and assigned to 0/+1 and 0/-1 redox couples. Both of these redo
x couples are quasi-reversible. It is suggested that the stability of
the 0/-1 redox couple is modulated by an EC scheme, whereby the initia
l reduction product [CpRu(NO)(tdas)](.-) undergoes a bending of the n
itrosyl ligand. The nitrosyl bending is observable at low temperature
in THF solvent. The nature of the HOMO and LUMO levels in CpRu(NO)(td
as) has been determined by extended Huckel molecular orbital calculati
ons, the results of which are discussed with respect to the electroche
mical data.