Tetrel Interactions from an Interacting Quantum Atoms Perspective

Molecules

JoséLuis Casals-Sainz¹  ÁngelMartín Pendás¹  AuroraCostales Castro¹  Evelio Francisco¹ 

[1] Departamento de Química Física y Analítica, Julián Clavería, 6, Facultad de Química, Universidad de Oviedo, 33006 Oviedo, Spain;

关键词: energy partition;    interacting quantum atoms;    quantum theory of atoms in molecules;    delocalization index;    covalent interaction;    self-energy;   

DOI  :  10.3390/molecules24122204

来源: DOAJ

【 摘 要 】

Tetrel bonds, the purportedly non-covalent interaction between a molecule that contains an atom of group 14 and an anion or (more generally) an atom or molecule with lone electron pairs, are under intense scrutiny. In this work, we perform an interacting quantum atoms (IQA) analysis of several simple complexes formed between an electrophilic fragment (A) (CH₃F, CH₄, CO₂, CS₂, SiO₂, SiH₃F, SiH₄, GeH₃F, GeO₂, and GeH₄) and an electron-pair-rich system (B) (NCH, NCO-, OCN-, F-, Br-, CN-, CO, CS, Kr, NC-, NH₃, OC, OH₂, SH-, and N₃-) at the aug-cc-pvtz coupled cluster singles and doubles (CCSD) level of calculation. The binding energy ( $E_{\mathrm{bind}}^{\mathrm{AB}}$ ) is separated into intrafragment and inter-fragment components, and the latter in turn split into classical and covalent contributions. It is shown that the three terms are important in determining $E_{\mathrm{bind}}^{\mathrm{AB}}$ , with absolute values that increase in passing from electrophilic fragments containing C, Ge, and Si. The degree of covalency between A and B is measured through the real space bond order known as the delocalization index ( ${\delta }^{\mathrm{AB}}$ ). Finally, a good linear correlation is found between ${\delta }^{\mathrm{AB}}$ and $E_{\mathrm{xc}}^{\mathrm{AB}}$ , the exchange correlation (xc) or covalent contribution to $E_{\mathrm{bind}}^{\mathrm{AB}}$ .

【 授权许可】

Unknown