Saurí Josep, Parella Teodor
Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Catalonia, Spain.
Magn Reson Chem. 2013 Sep;51(9):509-16. doi: 10.1002/mrc.3977. Epub 2013 Jun 18.
The effects of phase modulation due to homonuclear proton-proton coupling constants in HSQMBC-IPAP and HMBC-IPAP experiments are experimentally evaluated. We show that accurate values of small proton-carbon coupling constants, (n)J(CH), can be extracted even for phase-distorted cross-peaks obtained from a selHSQMBC experiment applied simultaneously on two mutually J-coupled protons. On the other hand, an assessment of the reliability of (n)J(CH) measurement from distorted cross-peaks obtained in broadband IPAP versions of equivalent HMBC and HSQMBC experiments is also presented. Finally, we show that HMBC-COSY experiments could be an excellent complement to HMBC for the measurement of small (n)J(CH) values.
通过实验评估了HSQMBC - IPAP和HMBC - IPAP实验中同核质子 - 质子耦合常数引起的相位调制效应。我们表明，即使对于通过同时应用于两个相互J耦合质子的selHSQMBC实验获得的相位失真交叉峰，也可以提取小质子 - 碳耦合常数(n)J(CH)的准确值。另一方面，还给出了对在等效HMBC和HSQMBC实验的宽带IPAP版本中获得的失真交叉峰进行(n)J(CH)测量可靠性的评估。最后，我们表明HMBC - COSY实验对于测量小(n)J(CH)值可能是HMBC的出色补充。
