In+ cation interactions with some organics:: ab initio molecular orbital and density functional theory

Ab initio molecular orbital and density functional theory studies were undertaken to investigate the structural and energetic characteristics of complexes of In+ with several different organic molecules for the first time. HF, MP2, QCISD, and CCD levels of theory in ab initio MO as well as B3LYP, B3PW91 hybrid functionals in density functional theory were used, A valence TZ + P basis set with relativistic effective core potentials was used for the In atom while the 6-311 + + G(3d, 2p) basis set was utilized for all other atoms. Both closed-shell (H2O, CH4, CH3OH, and C6H6) and open-shell (CH3 and C2H3) molecules were considered for complexation with In+. In+ affinities of 21.5, 24.8, 28.6, 18.4, and 23.0 kcal/mol were obtained with the B3PW91 hybrid functional for H2O, CH3OH, C6H6, CH3, and C2H3, respectively. The large values for the calculated affinities indicate the validity of our recent experimental detection of In+ ion attachment to some organic molecules. (C) 1999 Elsevier Science B.V. All rights reserved.