Better Characterization of Surface Organometallic Catalysts through Resolution Enhancement in Proton Solid State NMR Spectra
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- 作者：Fré ; dé ; ric Blanc ; Christophe Copé ; ret ; Jean Thivolle-Cazat ; Jean-Marie Basset ; Anne Lesage ; Lyndon Emsley ; Amritanshu Sinha ; Richard R. Schrock
- 刊名：Inorganic Chemistry
- 出版年：2006
- 出版时间：November 13, 2006
- 年：2006
- 卷：45
- 期：23
- 页码：9587 - 9592
- 全文大小：93K
- 年卷期：v.45,no.23(November 13, 2006)
- ISSN：1520-510X
文摘
Delayed-acquisition methods, namely, echo and constant-time-acquisition approaches, allow a significant improvementin resolution in the proton solid state NMR spectra of surface organometallic catalysts such as [syn-(SiO)Mo(=NAr)(=CHtBu)(CH2tBu)] and [(
SiO)Re(CtBu)(=CHtBu)(CH2tBu)] (syn/anti ratio = 1:1). This enables theobservation of all of the proton resonances, which is not possible with the simple proton single-pulse techniqueunder magic-angle spinning. For example, the methylene protons of the neopentyl ligands, buried in the large peakassociated 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-timeacquisition with heteronuclear carbon-proton correlation spectroscopy also improves the resolution of the 2D HETCORspectra.
SiO)Re(CtBu)(=CHtBu)(CH2tBu)] (syn/anti ratio = 1:1). This enables theobservation of all of the proton resonances, which is not possible with the simple proton single-pulse techniqueunder magic-angle spinning. For example, the methylene protons of the neopentyl ligands, buried in the large peakassociated 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-timeacquisition with heteronuclear carbon-proton correlation spectroscopy also improves the resolution of the 2D HETCORspectra.