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

DFT and MP2 calculations were used to determine the nature of non-covalent tellurium-π interactions in R 2 Te•••C 6 H 6 (R = H, F, Cl, CH 3) and C 4 H 4 Te•••C 6 H 6 systems. The results showed that the strength of Te•••π interaction follows the order F 2 Te > Cl 2 Te > tellurophene > H 2 Te > Me 2 Te. Also, the F 2 X•••π system complexes (X = Te or Se, π system = C 6 F 6 , C 6 (CH 3) 6 , Cr(C 6 H 6) 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 E int in the R 2 Te•••C 6 H 6 (R = H, F, Cl, CH 3) and C 4 H 4 Te•••C 6 H 6 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 E elstat and E orb in total interaction energy increases and the value of E int is relatively large. The present data also showed that the intermolecular Te•••π interactions are slightly stronger than corresponding Se•••π interactions.