resumo
An experimental and simulation investigation regarding the effect of various CRAMPS parameters (delays interleaved with the decoupling shape, z-rotation symmetry and offset frequency) on the DUMBO decoupling performance is presented using two model compounds, glycine and tyrosine Although the conclusions of this work may be extended to the other homonuclear-decoupling schemes, this work focuses essentially on the effect of adding interleaved delays to DUMBO decoupling during the indirect dimension using different 2D pulse-scheme architectures. While the simulations revealed an increasing loss of the spectral resolution with longer delays (from 0 to 6 mu s), the experimental 2D H-1 DUMBO NMR correlation spectra revealed that the inclusion of delays, during the indirect dimension, improves the H-1 resolution whether the z-rotation symmetry was used or not. The best experimental spectra are obtained when z-rotation symmetry and windows are combined. (C) 2011 Elsevier Inc. All rights reserved.
palavras-chave
SOLID-STATE NMR; NUCLEAR-MAGNETIC-RESONANCE; MULTIPLE-PULSE NMR; ANGLE-SPINNING FREQUENCIES; HIGH-ORDER; SPECTROSCOPY; SEQUENCES; MAS; KHZ
categoria
Chemistry; Physics; Spectroscopy
autores
Siegel, R; Mafra, L; Rocha, J
nossos autores
João Rocha
Prof. Catedrático
Luís Mafra
Investigador Principalagradecimentos
We acknowledge the Portuguese National NMR Network (RNRMN), supported with funds from Fundacao para a Ciencia e a Tecnologia (FCT). We acknowledge CICECO, FEDER and University of Aveiro. We also thank FCT for their general financial support (PTDC/QUI-QUI/100998/2008) and for Post-Doc grant SFRH/BPD/44355/2008 (to R.S.).