TY - JOUR
T1 - Fully Localized Mixed-Valence Oxidation Products of Molecules Containing Two Linked Dimolybdenum Units
T2 - An Effective Structural Criterion
AU - Cotton, F. Albert
AU - Dalal, Naresh S.
AU - Liu, Chun Y.
AU - Murillo, Carlos A.
AU - North, J. Micah
AU - Wang, Xiaoping
PY - 2003/10/22
Y1 - 2003/10/22
N2 - Two previously reported compounds [Mo2](CH3O) 2M(CH3O)2[Mo2] (Cotton, F. A.; Liu, C. Y.; Murillo, C. A.; Wang, X. Inorg. Chem. 2003, 42, 4619), in which [Mo 2] is an abbreviation for the quadruply bonded Mo2 4+ unit embraced by three (p-anisyl)NC(H)N(p-anisyl) anions and M = Zn (1) or Co (2), have been chemically oxidized. One-electron oxidation products [Mo2](CH3O)2M(CH3o) 2[Mo2](PF6) (3, M = Zn; 4, M = Co) and the two-electron oxidation product [Mo2](CH3O) 2Zn(CH3O)(OH)[Mo2](PF6)2 (5) have been isolated and structurally characterized. As expected, oxidations occur at the dimolybdenum units, The mono-charged cations in 3 and 4 have asymmetric molecular structures with two distinct [Mo2] units. In each case, one of the [Mo2] units has a lengthened Mo-Mo bond distance of 2.151[1] Å, as expected for one-electron oxidation, whereas the other remains unchanged at 2.115[1] Å. These correspond to bond orders of 3,5 (σ2π4δ1) and 4.0 (σ2π4δ2) respectively. The crystallographic results thus show unambiguously that in the crystalline state, the mixed-valence compounds (3 and 4) are electronically localized and the unpaired electron is trapped on one [Mo2] unit, These results are supported by the EPR spectra, The doubly oxidized compound 5 has two equivalent [Mo2] units, both with a Mo-Mo bond distance of 2.149(1) Å. EPR and magnetic susceptibility measurements for 5 indicate that there is no significant ferromagnetic or antiferromagnetic spin coupling and the species is valence-trapped.
AB - Two previously reported compounds [Mo2](CH3O) 2M(CH3O)2[Mo2] (Cotton, F. A.; Liu, C. Y.; Murillo, C. A.; Wang, X. Inorg. Chem. 2003, 42, 4619), in which [Mo 2] is an abbreviation for the quadruply bonded Mo2 4+ unit embraced by three (p-anisyl)NC(H)N(p-anisyl) anions and M = Zn (1) or Co (2), have been chemically oxidized. One-electron oxidation products [Mo2](CH3O)2M(CH3o) 2[Mo2](PF6) (3, M = Zn; 4, M = Co) and the two-electron oxidation product [Mo2](CH3O) 2Zn(CH3O)(OH)[Mo2](PF6)2 (5) have been isolated and structurally characterized. As expected, oxidations occur at the dimolybdenum units, The mono-charged cations in 3 and 4 have asymmetric molecular structures with two distinct [Mo2] units. In each case, one of the [Mo2] units has a lengthened Mo-Mo bond distance of 2.151[1] Å, as expected for one-electron oxidation, whereas the other remains unchanged at 2.115[1] Å. These correspond to bond orders of 3,5 (σ2π4δ1) and 4.0 (σ2π4δ2) respectively. The crystallographic results thus show unambiguously that in the crystalline state, the mixed-valence compounds (3 and 4) are electronically localized and the unpaired electron is trapped on one [Mo2] unit, These results are supported by the EPR spectra, The doubly oxidized compound 5 has two equivalent [Mo2] units, both with a Mo-Mo bond distance of 2.149(1) Å. EPR and magnetic susceptibility measurements for 5 indicate that there is no significant ferromagnetic or antiferromagnetic spin coupling and the species is valence-trapped.
UR - https://www.scopus.com/pages/publications/0142029084
U2 - 10.1021/ja036920+
DO - 10.1021/ja036920+
M3 - Article
AN - SCOPUS:0142029084
SN - 0002-7863
VL - 125
SP - 12945
EP - 12952
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 42
ER -