An Extended Study of Solid Prototypal Chromium and Molybdenum Compounds Using 53Cr and 95Mo Nuclear Magnetic Resonance Spectroscopy
EMSL Project ID
2620
Abstract
proposal is an extension of two projects which involve the study of low-ƒ× half-integer spin transition metal quadrupolar nuclei: 53Cr and 95Mo. Due to the unfavourable nuclear spin properties of these nuclei, chromium-53 (I = 3/2; N.A. = 9.55 %; ƒ = 5.64 MHz; Q = -0.15 barn) and molybdenum-95 (I = 5/2; N.A. = 15.72 %; ƒ = 6.54 MHz; Q = 0.022 barn), very few NMR studies have been carried out in the solid state. We have been successful in obtaining high-quality 53Cr and 95Mo solid-state NMR spectra of a series of model chromium and molybdenum compounds during previous visits to Pacific Northwest National Laboratories. The goal of this research is to characterize chromium and molybdenum chemical shift and electric field gradient tensors of prototypal compounds to provide further insight into the relationship between NMR observables and the local environments about chromium and molybdenum. One focus will be on a series of chromates, dichromates, molybdates, and dimolybdates which have proven to be good candidates for high-field studies. Secondly, we will investigate a series of chromium and molybdenum carbonyl compounds. As well, we will obtain spectra of the chromium piano-stool complex Cr(mesitylene)(CO)3 for comparison with previous work on Mo(mesitylene)(CO)3. In addition to standard solid-state NMR techniques, we will be employing the quadrupolar-Carr-Purcell-Meiboom-Gill (QCPMG) pulse sequence and the frequency-stepped ¡§skyline projection¡¨ method.
Project Details
Project type
Capability Research
Start Date
2002-10-01
End Date
2004-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members