Theoretical studies on the nature and strength of an intermolecular non-covalent Te•••π interaction

Abstract

ABSTRACTDFT and MP2 calculations were used to determine the nature of non-covalent tellurium–π interactions in R2Te•••C6H6 (R = H, F, Cl, CH3) and C4H4Te•••C6H6 systems. The results showed that the strength of Te···π interaction follows the order F2Te > Cl2Te > tellurophene > H2Te > Me2Te. Also, the F2X···π system complexes (X = Te or Se, π system = C6F6, C6(CH3)6, Cr(C6H6)2 and coronene) were studied for investigating the direction of charge flow in Te···π interaction. The obtained data expressed that the existence of electron withdrawing group on Te atom increases the strength of Te•••π interaction while the fluorine atoms on benzene ring decrease it. The breakdown of ΔEint in the R2Te···C6H6 (R = H, F, Cl, CH3) and C4H4Te···C6H6 systems using two dispersion corrected DFT methods showed that when the R group on divalent tellurium atom is an electron withdrawing substituent, the contribution of ΔEelstat and ΔEorb in total interaction energy increases and the value of ΔEint is relatively large. The present data also showed that the intermolecular Te···π interactions are slightly stronger than corresponding Se···π interactions.