trans-W(Cmesityl)(dmpe)2H: Revealing a Highly Polar W-H Bond and H-Mobility in Liquid and Solid State
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- 作者：Fenglou Zou ; Franck Furno ; Thomas Fox ; Helmut W. Schmalle ; Heinz Berke ; Jü ; rgen Eckert ; Zema Chowdhury ; Peter Burger
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：June 6, 2007
- 年：2007
- 卷：129
- 期：22
- 页码：7195 - 7205
- 全文大小：241K
- 年卷期：v.129,no.22(June 6, 2007)
- ISSN：1520-5126
文摘
The isotopomeric complexes trans-W(Cmesityl)[(C(H,D)3)2PCH2CH2P(C(H,D)3)2]2(H,D) 1-4 wereprepared. 2 (W(Cmesityl)(dmpe)2D) was used to study the Deuterium Quadrupole Coupling Constant (DQCC)and the ionicity of the W-D bond (DQCC = 34.1 kHz; ionicity 85%). 1 (W(Cmesityl)(dmpe)2H) shows severaldynamic exchange processes in solution, such as HW/HW, HW/ortho-Memesityl, and HW/H2 exchanges observedby NMR in combination with deuterium labeling studies and double label crossover experiments. Exceptfor the HW/H2, these reactions comprise elementary steps, which also appear along the isomerizationpathway of 1 into (2,3,5-trimethylphenylcarbyne)(dmpe)2WH (5) at 60 
C. 5 was characterized by an X-raydiffraction study. In the solid state only an HW/Mep exchange process prevails appearing at highertemperatures, which was identified by NMR and by Quasielastic Neutron Scattering. The latter also providedan activation barrier of 5 kcal/mol and a "jump width" for the moving H nucleus in agreement with theHW···Mep distance of the X-ray diffraction study of 1.
C. 5 was characterized by an X-raydiffraction study. In the solid state only an HW/Mep exchange process prevails appearing at highertemperatures, which was identified by NMR and by Quasielastic Neutron Scattering. The latter also providedan activation barrier of 5 kcal/mol and a "jump width" for the moving H nucleus in agreement with theHW···Mep distance of the X-ray diffraction study of 1.