title: A Re(CO)5 fragment bonded to a polyhedral oligomeric hydroxysilsesquioxane as a model which gives further evidence to the existence of an unexpected Re(CO)5 surface species.
abstract: Reaction of Re(CO)5O3SCF3 with (c-C6H11)7Si8O12O-Li+ at 273 K under a CO atmosphere affords the [Re(CO)5OR] (R = (c-C6H11)7Si8O12) derivative (1). 1 is the first example of a rhenium pentacarbonyl bearing an OR ligand (R = alkyl, aryl, or silyl) stable enough to be characterized, and it represents also the first molecular model of the surface [Re(CO)5OSi] species formed by reductive carbonylation of silica-supported [Re(CO)3OH]4. At room temperature, 1 loses one carbonyl ligand and dimerizes to afford {Re(CO)4[(mu-O)O12Si8(c-C6H11)7]}2 (2), which has been characterized by X-ray diffraction and is the first reported example of a rhenium tetracarbonyl mu-oxo-bridged dimer of the type [Re(CO)4(mu-OR)]2.
authors.affiliation: Institute of Molecular Science and Technology of CNR, Via Golgi 19, 20133 Milan, Italy. e.lucenti@istm.cnr.it
authors.forename: Elena
authors.initials: E
authors.lastname: Lucenti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Alfonso
authors.forename: Piero
authors.initials: P
authors.lastname: Macchi
authors.forename: Mario
authors.initials: M
authors.lastname: Maranesi
authors.forename: Dominique
authors.initials: D
authors.lastname: Roberto
authors.forename: Angelo
authors.initials: A
authors.lastname: Sironi
authors.forename: Renato
authors.initials: R
authors.lastname: Ugo