1 J WSn as a Solution State Predictor for Tungsten−Tin Solid State Bond Length in Sterically Crowded Tungstenocene Stannyl Complexes

• Published in: Organometallics Vol. 24; no. 16; pp. 3897 - 3906
• Main Authors: Mobley, T. Andrew, Gandour, Rochelle, Gillis, Eric P, Nti-Addae, Kwame, Palchaudhuri, Rahul, Rajbhandari, Presha, Tomson, Neil, Vargas, Angel, Zheng, Qi
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.08.2005
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om049006d

A correlation between the tungsten tin solid state bond distance (r WSn) and the solution state one-bond scalar coupling of tungsten to tin (1 J WSn) is reported. This correlation was observed in hydrido- and chlorotungstenocene diorganostannyl chlorides (Cp2WXSnClR2, X = H (1), X = Cl (2)) with sterically demanding organic substituents (R = t Bu (1a, 2a), Ph (1b, 2b)). The different steric demands of the organic substituents ( t Bu and Ph) force the complexes 1a and 1b (or 2a and 2b) to adopt at 190 K in the solid state different, single rotameric conformations. For 1a and 2a, the t Bu substituents occupy the equatorial wedge of the tungstenocene, whereas for 1b and 2b the Ph substituents are rotated to place the chlorine in the equatorial wedge. Variable-temperature multinuclear NMR and density functional theory calculations at the B3LYP/LANL2DZ level indicate the possibility of low-lying conformational isomers for complexes 1b.