title: Intramolecular C-C agostic complexes: C-C sigma interactions by another name.
abstract: In this comprehensive review the developments in the synthesis, characterization and reactivity of complexes (s-, d- and f-block) in which a C-C single bond interacts with a metal centre are discussed: so called C-CM agostic complexes. Such species are of significant interest with regard to structure and bonding, the activation of C-C single bonds and, thus, catalytic methods of C-C bond formation (or activation). Examples of C-C agostic complexes of early and later transition metals, actinides and group 1 metals are discussed, along with C-C agostic interactions in metallacyclobutanes. Examples of Si-Si∙∙∙M, B-C∙∙∙M and B-B∙∙∙M agostic interactions are also presented. Throughout, the structural, spectroscopic and computational markers that indicate the likely presence of a C-C∙∙∙M agostic interaction in a complex are highlighted.
authors.affiliation: CNRS, LCC (Laboratoire de Chimie de Coordination), 205, route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France. michel.etienne@lcc-toulouse.fr.
authors.forename: Michel
authors.initials: M
authors.lastname: Etienne
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Weller