TY - JOUR
T1 - Preparation, characterization and electronic structure of W2(NMe2)2(ORf)4, where Rf = CMe2CF3, CMe(CF3)2 and C(CF3)3, as deduced by photoelectron spectroscopic studies and the single crystal X-ray structure for Rf = OCMe(CF3)2
AU - Budzichowski, Theodore A.
AU - Chisholm, Malcolm H.
AU - Tiedtke, Darin B.
AU - Gruhn, Nadine E.
AU - Lichtenberger, Dennis L.
PY - 1998
Y1 - 1998
N2 - The compounds W2(NMe2)2(OCMe2CF3) 4, 1, W2(NMe2)2(OCMe(CF3) 2)4, 2, and W2(NMe2)2 (OC(CF3)3)4, 3, have been obtained from reactions between W2(NMe2)6 and the respective fluoroalcohol in hydrocarbon solvents. The compounds 2 and 3 appear inert to further reaction with their fluoroalcohol at room temperature while 1 reacts further to give W2(OCMe2CF3)6. In solution NMR data indicate that all three compounds exist in a mixture of anti-and gauche-rotamers with restricted rotations about both W - N and W≡W bonds on the NMR time-scale. The solid-state molecular structure of 2 reveals a centrosymmetric NO2W≡WO2N core with W - W = 2.3107(6) Å, W - N = 1.914(4) Å, W - O = 1.959(3) and 1.907(3) Å and angles W - W - O/N within the range 100 to 110°. The gas phase photoelectron spectra for 1, 2 and 3 were obtained and are compared with that for W2(NMe2)6. The introduction of the fluoroalkoxide ligands has a pronounced effect in stabilizing the metal and nitrogen lone-pair based ionizations, and this effect is amplified by the successive replacement of each methyl group by a trifluoromethyl group. Also for the compounds 1, 2, and 3 the lowest ionization bands clearly reveal the removal of the degeneracy of the W - W π MOs as expected for anti and gauche complexes.
AB - The compounds W2(NMe2)2(OCMe2CF3) 4, 1, W2(NMe2)2(OCMe(CF3) 2)4, 2, and W2(NMe2)2 (OC(CF3)3)4, 3, have been obtained from reactions between W2(NMe2)6 and the respective fluoroalcohol in hydrocarbon solvents. The compounds 2 and 3 appear inert to further reaction with their fluoroalcohol at room temperature while 1 reacts further to give W2(OCMe2CF3)6. In solution NMR data indicate that all three compounds exist in a mixture of anti-and gauche-rotamers with restricted rotations about both W - N and W≡W bonds on the NMR time-scale. The solid-state molecular structure of 2 reveals a centrosymmetric NO2W≡WO2N core with W - W = 2.3107(6) Å, W - N = 1.914(4) Å, W - O = 1.959(3) and 1.907(3) Å and angles W - W - O/N within the range 100 to 110°. The gas phase photoelectron spectra for 1, 2 and 3 were obtained and are compared with that for W2(NMe2)6. The introduction of the fluoroalkoxide ligands has a pronounced effect in stabilizing the metal and nitrogen lone-pair based ionizations, and this effect is amplified by the successive replacement of each methyl group by a trifluoromethyl group. Also for the compounds 1, 2, and 3 the lowest ionization bands clearly reveal the removal of the degeneracy of the W - W π MOs as expected for anti and gauche complexes.
KW - Photoelectron spectroscopic studies
KW - Single crystal X-ray structure
KW - W(NMe)(OR)
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U2 - 10.1016/S0277-5387(97)00360-4
DO - 10.1016/S0277-5387(97)00360-4
M3 - Article
AN - SCOPUS:0040585560
SN - 0277-5387
VL - 17
SP - 705
EP - 711
JO - Polyhedron
JF - Polyhedron
IS - 5-6
ER -