title: Better characterization of surface organometallic catalysts through resolution enhancement in proton solid state NMR spectra.
abstract: Delayed-acquisition methods, namely, echo and constant-time-acquisition approaches, allow a significant improvement in resolution in the proton solid state NMR spectra of surface organometallic catalysts such as [syn-(SiO)Mo(=NAr)(=CH(t)Bu)(CH2(t)Bu)] and [(SiO)Re(C(t)Bu)(=CH(t)Bu)(CH2(t)Bu)] (syn/anti ratio = 1:1). This enables the observation of all of the proton resonances, which is not possible with the simple proton single-pulse technique under magic-angle spinning. For example, the methylene protons of the neopentyl ligands, buried in the large peak associated with all of the methyls in the 1H MAS spectrum, can easily be identified by recording a delayed-acquisition spectrum (resolution enhancement of a factor of 3 is obtained). Moreover, combining constant-time acquisition with heteronuclear carbon-proton correlation spectroscopy also improves the resolution of the 2D HETCOR spectra.
authors.affiliation: Laboratoire de Chimie Organométallique de Surface, UMR 9986 CNRS - ESCPE Lyon, 43 bd du 11 Novembre 1918, F-69616 Villeurbanne Cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Blanc
authors.forename: Christophe
authors.initials: C
authors.lastname: Copéret
authors.forename: Jean
authors.initials: J
authors.lastname: Thivolle-Cazat
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Basset
authors.forename: Anne
authors.initials: A
authors.lastname: Lesage
authors.forename: Lyndon
authors.initials: L
authors.lastname: Emsley
authors.forename: Amritanshu
authors.initials: A
authors.lastname: Sinha
authors.forename: Richard R
authors.initials: RR
authors.lastname: Schrock