Liu Mingxiu, Li Qingzhong, Scheiner Steve
The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, People's Republic of China.
Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA.
Phys Chem Chem Phys. 2017 Feb 15;19(7):5550-5559. doi: 10.1039/c6cp07531b.
Ab initio calculations have been performed for the complexes H-PyTXNH and H-furanTFNH (T = C, Si, and Ge; X = F and Cl) with focus on geometries, energies, orbital interactions, and electron densities to study the influence of protonation on the strength of tetrel bonding. The primary interaction mode between α/β-furanCF/p-PyCF and NH changes from an FH hydrogen bond to a CN tetrel bond as a result of protonation. Importantly, the protonation has a prominent enhancing effect on the strength of tetrel bonding with an increase in binding energy from 14 to 30 kcal mol. The tetrel bonding becomes stronger in the order H-p-PySiFNH < H-m-PySiFNH < H-o-PySiFNH, showing a reverse trend from that of the neutral analogues. In addition, there is competition between the tetrel and hydrogen bonds in the protonated complexes, in which the hydrogen bond is favored in the complexes of H-p-PyCF but the tetrel bond is preferred in the complexes of H-p-PyTX (T = Si, Ge; X = F, Cl) and H-o/m-PySiF.
对配合物H-PyTXNH和H-呋喃TFNH（T = C、Si和Ge；X = F和Cl）进行了从头算计算，重点关注几何结构、能量、轨道相互作用和电子密度，以研究质子化对四配位键强度的影响。质子化导致α/β-呋喃CF/p-吡啶CF与NH之间的主要相互作用模式从FH氢键转变为CN四配位键。重要的是，质子化对四配位键的强度有显著的增强作用，结合能从14千卡/摩尔增加到30千卡/摩尔。四配位键的强度按H-p-吡啶基硅氟NH < H-m-吡啶基硅氟NH < H-o-吡啶基硅氟NH的顺序增强，呈现出与中性类似物相反的趋势。此外，质子化配合物中四配位键和氢键之间存在竞争，其中在H-p-吡啶基CF配合物中氢键更有利，但在H-p-吡啶基TX（T = Si、Ge；X = F、Cl）和H-o/m-吡啶基硅氟配合物中四配位键更受青睐。
