TY - JOUR
T1 - Ancillary ligand effects upon dithiolene redox noninnocence in tungsten Bis(dithiolene) complexes
AU - Yan, Yong
AU - Keating, Christopher
AU - Chandrasekaran, Perumalreddy
AU - Jayarathne, Upul
AU - Mague, Joel T.
AU - Debeer, Serena
AU - Lancaster, Kyle M.
AU - Sproules, Stephen
AU - Rubtsov, Igor V.
AU - Donahue, James P.
PY - 2013/6/3
Y1 - 2013/6/3
N2 - An expanded set of compounds of the type [W(S2C 2Me2)2L1L2]n (n = 0: L1 = L2 = CO, 1; L1 = L2 = CNtBu, 2; L1 = CO, L2 = carbene, 3; L 1 = CO, L2 = phosphine, 4; L1 = L2 = phosphine, 5. n = 2-: L1 = L2 = CN-, [6] 2-) has been synthesized and characterized. Despite isoelectronic formulations, the compound set reveals gradations in the dithiolene ligand redox level as revealed by intraligand bond lengths, υCCchelate, and rising edge energies in the sulfur K-edge X-ray absorption spectra (XAS). Differences among the terminal series members, 1 and [6]2-, are comparable to differences seen in homoleptic dithiolene complexes related by full electron transfer to/from a dithiolene-based MO. The key feature governing these differences is the favorable energy of the CO π* orbitals, which are suitably positioned to overlap with tungsten d orbitals and exert an oxidizing effect on both metal and dithiolene ligand via π-backbonding. The CN- π* orbitals are too high in energy to mix effectively with tungsten and thus leave the filled dithiolene π* orbitals unperturbed. This work shows how, and the degree to which, the redox level of a noninnocent ligand can be modulated by the choice of ancillary ligands(s).
AB - An expanded set of compounds of the type [W(S2C 2Me2)2L1L2]n (n = 0: L1 = L2 = CO, 1; L1 = L2 = CNtBu, 2; L1 = CO, L2 = carbene, 3; L 1 = CO, L2 = phosphine, 4; L1 = L2 = phosphine, 5. n = 2-: L1 = L2 = CN-, [6] 2-) has been synthesized and characterized. Despite isoelectronic formulations, the compound set reveals gradations in the dithiolene ligand redox level as revealed by intraligand bond lengths, υCCchelate, and rising edge energies in the sulfur K-edge X-ray absorption spectra (XAS). Differences among the terminal series members, 1 and [6]2-, are comparable to differences seen in homoleptic dithiolene complexes related by full electron transfer to/from a dithiolene-based MO. The key feature governing these differences is the favorable energy of the CO π* orbitals, which are suitably positioned to overlap with tungsten d orbitals and exert an oxidizing effect on both metal and dithiolene ligand via π-backbonding. The CN- π* orbitals are too high in energy to mix effectively with tungsten and thus leave the filled dithiolene π* orbitals unperturbed. This work shows how, and the degree to which, the redox level of a noninnocent ligand can be modulated by the choice of ancillary ligands(s).
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U2 - 10.1021/ic4009174
DO - 10.1021/ic4009174
M3 - Article
C2 - 23675834
AN - SCOPUS:84878654439
SN - 0020-1669
VL - 52
SP - 6743
EP - 6751
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 11
ER -