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A systematic investigation on the SN2 displacement reactions of nine carbene radical anions toward the substrate CH3Cl has been theoretically carried out using the popular density functional theory functional BHandHLYP level with different basis sets 6-31+G (d, p)/relativistic effective core potential (RECP), 6-311++G (d, p)/RECP, and aug-cc-pVTZ/RECP. The studied models are CX1X2•− + CH3Cl → X2X1CH3C• + Cl−, with CX1X2•− = CH2•−, CHF•−, CHCl•−, CHBr•−, CHI•−, CF2•−, CCl2•−, CBr2•−, and CI2•−. The main results are proposed as follows: (a) Based on natural bond orbital (NBO), proton affinity (PA), and ionization energy (IE) analysis, reactant CH2•− should be a strongest base among the anion-containing species (CX1X2•−) and so more favorable nucleophile. (b) Regardless of frontside attacking pathway or backside one, the SN2 reaction starts at an identical precomplex whose formation with no barrier. (c) The back-SN2 pathway is much more preferred than the front-SN2 one in terms of the energy gaps [Δ E [ABSTRACT FROM AUTHOR]

A systematic investigation on the H‐abstraction reactions of 8 carbene radical anions with CCl3H has been performed theoretically using the popular DFT functional BHandHLYP/aug‐cc‐pVTZ/RECP level of theory. As a result, our studies strongly suggest that the reactivity of the title reactions (CX1X2•− + CCl3H) present increase in the order: CHI•− < CHBr•− < CHCl•− < CHF•− for first halogen CHX•− and CCI2•− < CBr2•− < CCl2•− < CF2•− for second halogen CX2•−, more important, the reactions of the former exhibit more activity than those of corresponding the latter. Moreover, based on the NBO analysis, the Activation Strain model analysis and the correlations analyses of activation barrier with both PA and IE, respectively, we further confirm over the conclusion. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 [ABSTRACT FROM AUTHOR]

The mechanisms of the reaction of lanthanide ions (Ce and Pr) with the carbon dioxide were investigated at the B3LYP level of theory. The crossing points (CPs) between the different potential energy surfaces (PESs) have been located by means of the intrinsic reaction coordinate approach used by Yoshizawa et al., and corresponding minimum energy crossing points (MECPs) that we obtained by the mathematical algorithm proposed by Harvey et al. has also been used. In addition, possible spin inversion processes are discussed by means of spin-orbit coupling (SOC) calculations. The value of 61.68 cm (for MECP) and 69.17 cm (for MECP) for the SOC constants indicates that the spin crossing process in Ln + CO (∑) reaction can be occurred efficiently because of the large SOC involved. And the O-atom affinities (OA) testified that the argumentation is thermodynamically allowed. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 [ABSTRACT FROM AUTHOR]