Alkyl, Silyl, and Phosphane Ligands-Classical Ligands in Nonclassical Bonding Modes.
Alkyl, silyl, and phosphane ligands are amongst the most familiar and ubiquitous ligands in organometallic and coordination chemistry. The C, Si, and P donor atoms of these ligands are sp(3)-hybridized and the ligands are related to each other by the isolobal analogy: (CR(3))(-)&harrcir;(SiR(3))(-)&harrcir;PR(3). Herein, we demonstrate that although a number of unusual observations concerning the reactivity and bonding of these ligands appears unrelated at first sight, they in fact provide offer an exiting and consistent picture that may form the basis for new paradigms. The characterization of stable complexes in which alkyl, silyl, and phosphane ligands behave as symmetrical bridges confirms that there is no inherent thermodynamic instability associated with these bonding situations, and, in fact, reactivity studies suggest that these ligands should be able to bridge between metal centers in reaction intermediates or transition states.
Braunstein
Pierre
P
Laboratoire de Chimie de Coordination UMR CNRS 7513 Université Louis Pasteur 4, rue Blaise Pascal, 67070 Strasbourg Cédex (France).
Boag
Neil M.
NM