Vol. 16, issue 03, article # 6
pdf Zvereva N. A. Complexes with inorganic hydrides (NH3, PH3, AsH3). // Atmospheric and oceanic optics. 2003. V. 16. No. 03. P. 203-210.Copy the reference to clipboard
Abstract:
The optimal structures and harmonic vibrational frequencies of water complexes with NH3, PH3, AsH3 have been determined by the Restricted Hartree-Fock (RHF) and second order Moller-Plesset perturbation theory (MP2) with augmented correlation consistent double zeta basis set for NH3-H2O, PH3-H2O complexes and 6-31++G(d, p) basis set for AsH3-H2O. At the MP2 level, this basis set yields very accurate results for the structure, dipole moment, and harmonic vibrational frequencies of water monomer. Analysis of the structural trends revealed that the separation between the neighboring oxygen atom and the X (N, P, As) atom increases in the row from N to As. The harmonic vibrational frequencies corresponding to OHb ("bridge" hydrogen) stretches show large red shift by 224 cm-1 for the NH3-H2O complex, but for PH3-H2O and AsH3-H2O these shifts are about 20 cm-1. The intensities corresponding to the OHb stretches increase several orders of magnitude as a result of H-bonding. The intensity patterns are analyzed by means of electronic density redistribution, which reveals that intensification of the proton donor stretch is chiefly due to the increasing charge flux associated with H-bond formation.