Wei Yuanxin, Li Qingzhong, Scheiner Steve
Laboratory of Theoretical and Computational Chemistry and School of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005, China), Fax: (+86) 535-6902063.
Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322-0300, USA.
Chemphyschem. 2018 Mar 19;19(6):736-743. doi: 10.1002/cphc.201701136. Epub 2018 Feb 5.
The positive region that lies above the plane of F TO (T=C and Si) interacts with malondialdehyde (MDA), which contains an intramolecular H-bond. The T atom of F TO can lie either in the MDA molecular plane, forming a T⋅⋅⋅O tetrel bond, or F TO can stack directly above MDA in a parallel arrangement. The former structure is more stable than the latter, and in either case, F SiO engages in a much stronger interaction than does F CO, reaching nearly 200 kJ mol . The π-tetrel bond strengthens/weakens the MDA H-bond when the bond is formed to the hydroxyl/carbonyl group of MDA, and causes an accompanying inhibition/promotion of proton transfer within this H-bond; this effect is stronger for F SiO. These same aspects can be tuned by substituents placed on any of the C atoms of MDA, although their effects are not fully correlated with the electron-withdrawing or electron-releasing properties of the substituent. A new type of π-π tetrel bond occurs when the π-hole on the T atom of F TO approaches the middle carbon atom of MDA from above, and a similar configuration is also found between F TO and benzene. Evidence for extensive C⋅⋅⋅C π-π tetrel bonding in crystal materials is presented.
位于F TO平面（T = C和Si）上方的正电区域与含有分子内氢键的丙二醛（MDA）相互作用。F TO的T原子可以位于MDA分子平面内，形成T⋅⋅⋅O四元键，或者F TO可以以平行排列直接堆叠在MDA上方。前一种结构比后一种更稳定，在任何一种情况下，F SiO的相互作用都比F CO强得多，达到近200 kJ mol 。当π-四元键与MDA的羟基/羰基形成时，它会增强/减弱MDA氢键，并导致该氢键内质子转移的伴随抑制/促进；F SiO的这种效应更强。这些相同的方面可以通过放置在MDA任何一个C原子上的取代基来调节，尽管它们的效应与取代基的吸电子或供电子性质并不完全相关。当F TO的T原子上的π空穴从上方接近MDA的中间碳原子时，会出现一种新型的π-π四元键，并且在F TO和苯之间也发现了类似的构型。本文还给出了晶体材料中广泛存在C⋅⋅⋅C π-π四元键的证据。
