Adjusting the balance between hydrogen and chalcogen bonds
Adjusting the balance between hydrogen and chalcogen bonds
复制标题
调整氢键和硫键之间的平衡
DOI：
10.1039/d2cp04591e
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发表时间：
2022
影响因子：
3.3
通讯作者：
Scheiner, Steve
中科院分区：
文献类型：
--
作者：
Scheiner, Steve
将X1COOH的羧基与C原子上含有取代基的1,2,5-硫代二唑环配对，组装成一个配合物。羧基的OH向环的N原子提供一个质子，形成OH⋯N氢键（HB），而其羰基O与Y = S, Se， Te的环形成Y⋯O硫键（ChB）。通过将Y原子的大小从S增大到Se再增大到Te， ChB得到强化。在酸上放置一个吸电子基团（EWG） X1，增强HB，减弱ChB；当ewg放在环上时，情况正好相反。通过在两个单元上选择合适的取代基，可以在这两个键的强度之间达到近乎完美的平衡。这些键强度也反映在各种原子的化学屏蔽和每个键直接涉及的原子核之间的耦合的核磁共振波谱特性上。
A complex is assembled which pairs a carboxyl group of X1COOH with a 1,2,5-chalcogenadiazole ring containing substituents on its C atoms. The OH of the carboxyl group donates a proton to a N atom of the ring to form a OH⋯N H-bond (HB), while its carbonyl O engages in a Y⋯O chalcogen bond (ChB) with the ring in which Y = S, Se, Te. The ChB is strengthened by enlarging the size of the Y atom from S to Se to Te. Placement of an electron-withdrawing group (EWG) X1 on the acid strengthens the HB while weakening the ChB; the reverse occurs when EWGs are placed on the ring. By selection of the proper substituents on the two units, it is possible to achieve a near perfect balance between the strengths of these two bonds. These bond strengths are also reflected in the NMR spectroscopic properties of the chemical shielding of the various atoms and the coupling between the nuclei directly involved in each bond.