ADEQUATE CR: 13C connectivity mapping in indirect detection mode with composite refocusing |
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Authors: | Christy George N Chandrakumar |
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Institution: | MRI‐MRS Centre, Department of Chemistry, Indian Institute of Technology – Madras, , Chennai, 600036 Tamil Nadu, India |
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Abstract: | We report a novel rare spin correlation experiment termed ADEQUATE with composite refocusing (CR), which is the 1H‐detected version of 2D INADEQUATE CR. ADEQUATE CR begins with a polarization transfer from protons to the attached carbon, followed by 13C–13C double‐quantum (DQ) preparation. Unlike the ADEQUATE class of experiments, 13C DQ coherence is converted after evolution to single‐quantum single transitions (SQ‐STs) by CR. 13C SQ‐ST is then transferred back to the coupled protons by a coherence order selective reconversion. The present sequence produces partial transition selectivity in the 1H dimension as does 1H Indirect detected 13C Low‐Abundance Single‐transition correlation Spectroscopy (HICLASS), thereby mitigating the reduction in sensitivity enhancement because of the presence of homonuclear proton couplings. However, unlike HICLASS (which is an experiment that involves SQ‐TS evolution), no homonuclear zero quantum mixing is required on the 13C channel in the present experiment. Experimental results are demonstrated on a variety of samples, establishing the efficiency of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd. |
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Keywords: | NMR 1H 13C ADEQUATE CR ADEQUATE rare spin correlation HICLASS INADEQUATE 1H transition selectivity 1H‐detected INEPT‐INADEQUATE |
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