Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
Magn Reson Chem. 2010 Jan;48(1):61-7. doi: 10.1002/mrc.2541.
The (15)N and (13)C chemical shifts of 6-(fluoro, chloro, bromo, and iodo)purine 2'-deoxynucleoside derivatives in deuterated chloroform were measured. The (15)N chemical shifts were determined by the (1)H-(15)N HMBC method, and complete (15)N chemical-shift assignments were made with the aid of density functional theory (DFT) calculations. Inclusion of solvation effects significantly improved the precision of the calculations of (15)N chemical shifts. Halogen-substitution effects on the (15)N and (13)C chemical shifts of purine rings are discussed in the context of DFT results. The experimental coupling constants for (19)F interacting with (15)N and (13)C of the 6-fluoropurine 2-deoxynuleoside are compared with those from DFT calculations.
测定了氘代氯仿中 6-（氟、氯、溴和碘）嘌呤 2'-脱氧核苷衍生物的（15）N 和（13）C 化学位移。（15）N 化学位移通过（1）H-（15）N HMBC 方法确定，并借助密度泛函理论（DFT）计算完成了完整的（15）N 化学位移分配。包括溶剂化效应显著提高了（15）N 化学位移计算的精度。根据 DFT 结果讨论了嘌呤环上卤素取代对（15）N 和（13）C 化学位移的影响。比较了实验测定的 6-氟嘌呤 2-脱氧核苷中（19）F 与（15）N 和（13）C 相互作用的偶合常数与 DFT 计算值。
