Effects of substituents on intermolecular interaction and stability of complexes of CO2 and CH3OCHX2 (X = H, F, Cl, Br, CH3)
Abstract
The structures, stability and effect of substituents on the complexes of CH 3 OCHX 2 with CO 2 were examined by ab initio quantum calculations. The interaction energies corrected both ZPE and BSSE at MP2/aug-cc-pVTZ//MP2/6-311++G(2d,2p) range from - 2.8 kJ.mol -1 to - 15 . 1 kJ.mol -1 . It is remarkable that the substitution of two H atoms by di-halogen ones leads to a decrease of 1.4-2.6 kJ.mol -1 in energy while that by two methyl groups induces a stabilization enhancement of 1.8 kJ.mol -1 . The stability of CH 3 OCHX 2 ∙∙∙ 1CO 2 di-halogenated derivatives tends to increase from X = F via Cl and to Br. AIM and NBO results indicate that intermolecular interactions are weakly noncovalent interactions, and the C ∙∙∙ O tetrel bond plays the crucial role in stabilizing complexes. In addition, SAPT2+ analysis shows a significant contribution of the attractive electrostatic component as compared to the dispersion and induction one in complex stabilization.