ORGANOMETALLIC NITROSYL CHEMISTRY .42. UNAMBIGUOUS EXAMPLE OF A ETA-2-BENZYL GROUP FUNCTIONING AS A FORMAL 3-ELECTRON LIGAND - SOLID-STATE MOLECULAR-STRUCTURE OF CPSTARMO(NO)(CH2SIME3)(ETA-2-CH2C6H5)1

Sequential treatment at 20 °C of Cp*Mo-(NO)(η2-CH2Ph)Cl in Et2O first with an equimolar amount of Me3SiCH2MgCl and then water affords Cp*Mo(NO)-(CH2SiMe3)(η2-CH2Ph), which is isolable in 82% yield as red, prismatic crystals. A single-crystal X-ray crystallography analysis of the product complex has confirmed its formulation and has determined that it possesses a “three-legged piano stool” molecular structure. The chemically most interesting result of this analysis is the establishment of the intramolecular dimensions of the Mo-(η2-CH2Ph) grouping, which indicate that the η2-benzyl group functions as a three-electron ligand via C-Moσ bonds involving its methylene and ipso carbon atoms. © 1990, American Chemical Society. All rights reserved.