Selent Marcin, Nyman Jonas, Roukala Juho, Ilczyszyn Marek, Oilunkaniemi Raija, Bygrave Peter J, Laitinen Risto, Jokisaari Jukka, Day Graeme M, Lantto Perttu
NMR Research Unit, Faculty of Science, University of Oulu, 90014, Oulu, Finland.
Faculty of Chemistry, Wrocław University, Joliot Curie 14, 50-383, Wrocław, Poland.
Chemistry. 2017 Apr 19;23(22):5258-5269. doi: 10.1002/chem.201604797. Epub 2017 Feb 14.
An approach is presented for the structure determination of clathrates using NMR spectroscopy of enclathrated xenon to select from a set of predicted crystal structures. Crystal structure prediction methods have been used to generate an ensemble of putative structures of o- and m-fluorophenol, whose previously unknown clathrate structures have been studied by Xe NMR spectroscopy. The high sensitivity of the Xe chemical shift tensor to the chemical environment and shape of the crystalline cavity makes it ideal as a probe for porous materials. The experimental powder NMR spectra can be used to directly confirm or reject hypothetical crystal structures generated by computational prediction, whose chemical shift tensors have been simulated using density functional theory. For each fluorophenol isomer one predicted crystal structure was found, whose measured and computed chemical shift tensors agree within experimental and computational error margins and these are thus proposed as the true fluorophenol xenon clathrate structures.
本文提出了一种利用包合氙的核磁共振光谱法来确定笼合物结构的方法，以便从一组预测的晶体结构中进行选择。晶体结构预测方法已被用于生成邻氟苯酚和间氟苯酚假定结构的集合，其先前未知的笼合物结构已通过氙核磁共振光谱进行了研究。氙化学位移张量对晶体腔的化学环境和形状具有高灵敏度，这使其成为多孔材料理想的探针。实验粉末核磁共振光谱可用于直接确认或否定由计算预测生成的假设晶体结构，其化学位移张量已使用密度泛函理论进行了模拟。对于每种氟苯酚异构体，都发现了一种预测的晶体结构，其测量和计算的化学位移张量在实验和计算误差范围内一致，因此这些结构被提议为真正的氟苯酚氙笼合物结构。
