Hoeck Casper, Gotfredsen Charlotte H, Sørensen Ole W
Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
J Magn Reson. 2017 Feb;275:68-72. doi: 10.1016/j.jmr.2016.11.019. Epub 2016 Dec 1.
A novel method, Spin-State-Selective (S) HMBC hetero, for accurate measurement of heteronuclear coupling constants is introduced. The method extends the S HMBC technique for measurement of homonuclear coupling constants by appending a pulse sequence element that interchanges the polarization in C-H methine pairs. This amounts to converting the spin-state selectivity from H spin states to C spin states in the spectra of long-range coupled H spins, allowing convenient measurement of heteronuclear coupling constants similar to other S or E.COSY-type methods. As usual in this type of techniques, the accuracy of coupling constant measurement is independent of the size of the coupling constant of interest. The merits of the new method are demonstrated by application to vinyl acetate, the alkaloid strychnine, and the carbohydrate methyl β-maltoside.
介绍了一种用于精确测量异核耦合常数的新方法——自旋态选择性（S）HMBC 异核法。该方法通过附加一个能在 C-H 次甲基对中交换极化的脉冲序列元件，扩展了用于测量同核耦合常数的 S HMBC 技术。这相当于在远程耦合 H 自旋的光谱中将自旋态选择性从 H 自旋态转换为 C 自旋态，从而能够像其他 S 或 E.COSY 型方法一样方便地测量异核耦合常数。与这类技术通常情况一样，耦合常数测量的准确性与所关注的耦合常数大小无关。通过将该新方法应用于醋酸乙烯酯、生物碱士的宁和碳水化合物甲基 β-麦芽糖苷，证明了其优点。
