1JWSn as a Solution State Predictor for Tungsten-Tin Solid State Bond Length in Sterically Crowded Tungstenocene Stannyl Complexes

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• 作者：T. Andrew Mobley ; Rochelle Gandour ; Eric P. Gillis ; Kwame Nti-Addae ; Rahul Palchaudhuri ; Presha Rajbhandari ; Neil Tomson ; Angel Vargas ; and Qi Zheng
• 刊名：Organometallics
• 出版年：2005
• 出版时间：August 1, 2005
• 年：2005
• 卷：24
• 期：16
• 页码：3897 - 3906
• 全文大小：334K
• 年卷期：v.24,no.16(August 1, 2005)
• ISSN：1520-6041

文摘

A correlation between the tungsten tin solid state bond distance (r_WSn) and the solutionstate one-bond scalar coupling of tungsten to tin (¹J_WSn) is reported. This correlation wasobserved in hydrido- and chlorotungstenocene diorganostannyl chlorides (Cp₂WXSnClR₂, X= H (1), X = Cl (2)) with sterically demanding organic substituents (R = ^tBu (1a, 2a), Ph(1b, 2b)). The different steric demands of the organic substituents (^tBu and Ph) force thecomplexes 1a and 1b (or 2a and 2b) to adopt at 190 K in the solid state different, singlerotameric conformations. For 1a and 2a, the ^tBu substituents occupy the equatorial wedgeof the tungstenocene, whereas for 1b and 2b the Ph substituents are rotated to place thechlorine in the equatorial wedge. Variable-temperature multinuclear NMR and densityfunctional theory calculations at the B3LYP/LANL2DZ level indicate the possibility of low-lying conformational isomers for complexes 1b.