Scalar Cross-Relaxation Detected in the NOESY Spectra of Oxazolidines and Thiazolidines
作者:Tharindi D. Panduwawala、Laia Josa-Culleré、Ilya Kuprov、Barbara Odell、Mark G. Moloney、Timothy D. W. Claridge
DOI:10.1021/acs.joc.6b00458
日期:2016.5.20
Anomalous cross-peaks observed in the NOESY spectra of 2,4-disubstituted thiazolidines and oxazolidines that cannot be attributed to classical dipolar NOE or chemical exchange peaks have been investigated experimentally and computationally and have been shown to arise from scalar cross-relaxation of the first kind. This process is stimulated by the relatively slow modulation of scalar couplings and
在实验和计算上已经研究了不能归因于经典偶极NOE或化学交换峰的2,4-二取代噻唑烷和恶唑烷在NOESY光谱中观察到的异常峰间峰,这些峰间峰是通过实验和计算得出的,并且证明是由于第一个的标量交叉松弛种类。标量偶合的相对较慢的调制刺激了该过程,对于所研究的系统,该过程是由氨基氮的开关质子交换缓慢引起的,该过程受溶液温度,酸度和浓度影响。对于许多质子交换在毫秒时间尺度上发生的系统,该机制可能很重要,并且如果不认识它们的真实起源,对这些交叉峰的误解可能会导致错误的结论。