Verma Ajay, Parihar Rashmi, Bhattacharya Subrato, Baishya Bikash
Centre of Biomedical Research (Formerly Centre of Biomedical Magnetic Resonance), SGPGIMS Campus, Raebareli Road, Lucknow, 226014, U. P., India.
Department of Chemistry, Institute of Science, Banaras Hindu University, Banaras, 221005, U. P., India.
Chemphyschem. 2017 Nov 3;18(21):3076-3082. doi: 10.1002/cphc.201700662. Epub 2017 Oct 9.
A diagonal suppressed F decoupled total correlation spectroscopy(TOCSY) experiment is developed for analyses of complex mixtures. In 2D homonuclear correlation, assignment of the cross peaks is crucial for structure elucidation. However, when cross peaks are close to the diagonal peaks in overcrowded spectral regions, their assignment becomes tedious. In complex mixtures, the presence of multiple spectra along with broad and complex proton multiplets owing to homonuclear scalar couplings degrade the resolution to the extent that assignment of various cross peaks becomes tedious or impossible. Herein, a diagonal suppressed total correlation technique with F decoupling is presented to improve the resolution of the cross peaks. The resolution of the cross peaks is improved by both diagonal suppression as well as the collapse of the multiplets to singlets. Application of the method to a few mixtures of organic compounds reveals better identification of the cross peaks relative to other TOCSY variants.
开发了一种用于分析复杂混合物的对角线抑制F去耦全相关光谱（TOCSY）实验。在二维同核相关中，交叉峰的归属对于结构解析至关重要。然而，当交叉峰在过度拥挤的光谱区域靠近对角线峰时，它们的归属变得繁琐。在复杂混合物中，由于同核标量耦合，多个光谱以及宽而复杂的质子多重峰的存在会降低分辨率，以至于各种交叉峰的归属变得繁琐或不可能。在此，提出了一种具有F去耦的对角线抑制全相关技术，以提高交叉峰的分辨率。通过对角线抑制以及多重峰坍缩为单峰，交叉峰的分辨率得到了提高。将该方法应用于几种有机化合物混合物，相对于其他TOCSY变体，交叉峰的识别效果更好。
