Competition between hydrogen bond , halogen bond and chalcogenbond in complexes of N-methylidenemethanamine(C۲H۵N )with HYX(Y=O, Sand X=F, Cl, Br and I).

An ab initio study of the complexes formed by N-methylidenemethanamine(C۲H۵N )withHYX(Y=O, S and X=F, Cl, Br and I) has been carried out at the MP۲/aug-cc-PVDZcomputational level. Interaction of HOX with N-methylidenemethanamine (C۲H۵N ) lead to bothhydrogen bond (C۲H۵N -HB) as well as halogen bond (C۲H۵N -XB) complexesMeanwhileInteraction of HSX with N-methylidenemethanamine (C۲H۵N ) lead tohydrogen bond (C۲H۵N -HB) , halogen bond (C۲H۵N -XB) andchalcogenbond(C۲H۵N -YB) complexes The interactionstrength and properties in all complexes are analysed with atoms in molecules (AIM) and naturalbond orbital (NBO) theories.Calculations were performed using the Gaussian ۰۹ system of codes. The geometries of theisolated HYX(Y=O, S and X=F, Cl, Br and I) and C۲H۵N molecules as well as HYX-C۲H۵Ncomplexes were fully optimized at the MP۲ level of theory [۱] with the aug-cc-pVDZ basis setfor all atoms, except iodine, for which the DGDZVP[۲] was used. Harmonic vibrationalfrequency calculations certified the structures as minima and provide the evaluation of the zeropoint energy (ZPE). The counterpoise procedure was used to correct the interaction energy forthe basis set superposition error[۳]. The AIM۲۰۰۰ package and AIMAll[۴] were used to obtainbond properties; and to plot molecular graphs. The natural bond orbital (NBO) method has beenused to evaluate the interaction of occupied and empty orbitals with the NBO package suppliedwith Gaussian ۰۹.

کلیدواژه ها:

Hydrogen bond ، halogen bond ، chalcogen bond ، blue shift ، N-methylidenemethanamine.