Bigler Peter, Melendez Camilo, Furrer Julien
Departement für Chemie, Biochemie und Pharmazie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
Molecules. 2021 Jun 8;26(12):3490. doi: 10.3390/molecules26123490.
We propose a new C DEPTQ NMR experiment, based on the improved DEPTQ experiment, which is designed to unequivocally identify all carbon multiplicities (Cq, CH, CH, and CH) in two experiments. Compared to this improved DEPTQ experiment, the DEPTQ is shorter and the different evolution delays are designed as spin echoes, which can be tuned to different values; this is especially valuable when a large range of J coupling constants is to be expected. These modifications allow (i) a mutual leveling of the DEPT signal intensities, (ii) a reduction in cross-talk in the Cq/CH spectrum, and (iii) more consistent and cleaner CH/CH edited spectra. The new DEPTQ is expected to be attractive for fast C analysis of small-to medium sized molecules, especially in high-throughput laboratories. With concentrated samples and/or by exploiting the high sensitivity of cryogenically cooled C NMR probeheads, the efficacy of such investigations may be improved, as it is possible to unequivocally identify all carbon multiplicities, with only one scan, for each of the two independent DEPTQ experiments and without loss of quality.
我们基于改进的DEPTQ实验提出了一种新的C DEPTQ NMR实验，该实验旨在通过两个实验明确识别所有碳的多重性（Cq、CH、CH₂和CH₃）。与这种改进的DEPTQ实验相比，新的DEPTQ实验时间更短，且不同的演化延迟设计为自旋回波，可调整为不同的值；当预期有大范围的J耦合常数时，这一点尤其有价值。这些改进使得（i）DEPT信号强度相互均衡，（ii）Cq/CH谱中的串扰减少，以及（iii）CH₂/CH₃编辑谱更一致、更清晰。新的DEPTQ有望对中小分子的快速碳分析具有吸引力，特别是在高通量实验室中。使用浓缩样品和/或利用低温冷却的碳核磁共振探头的高灵敏度，此类研究的效率可能会提高，因为对于两个独立的DEPTQ实验中的每一个，仅通过一次扫描就可以明确识别所有碳的多重性，且不会损失质量。
