Effect of ionic charge on O-H•••Se hydrogen bond: A computational study

Complexes between para-substituted cationic phenol and SeH2 have been investigated in electronic ground state at the B3LYP, B3PW91, and omega B97xD levels of theory using 6-311++G(3df,3pd) basis set. Various electron-donating and withdrawing substituents (-NH2, -OH, -CH3, -H, -F, -Cl, -CN, and -NO2) are used to characterize electronic substituent effect on intermolecular O+-H center dot center dot center dot Se hydrogen bond. Electron withdrawing substituent increases hydrogen bond stabilization energy and red shift in O-H stretching frequency. Introduction of a positive charge transforms weak hydrogen bond of neutral O-H center dot center dot center dot Se type into a strong hydrogen bond. Complexation induced changes on various hydrogen bond parameters, such as, stabilization energy, change in O-H bond length, change in O-H stretching frequency, extent of charge transfer from hydrogen bond acceptor to donor, hydrogen bond orders, electron density at the hydrogen bond critical point exhibit conventional electronic substitution effect, Stabilization energy of O+-H center dot center dot center dot Y hydrogen bond are similar in the complexes between cationic phenol and SH2/SeH2, whereas it is almost twice with OH2 in case of O+-H center dot center dot center dot Y hydrogen bond. (C) 2016 Elsevier B.V. All rights reserved.