Singlet Methylene Insertion Into Polar O-H and N-H Bonds of Water and Ammonia-Ab Initio and DFT Study

Correlated ab initio molecular orbital, OFT, QCISD, G3MP2, and QCISD(T) calculations have been used to investigate the geometries, energetics, and mechanisms governing the insertion reactions of (CH2)-C-1 into O-H and N-H bonds of water and ammonia, respectively, in gas phase adopting 6-311+ +g(d, p) basis set. It is found that (CH2)-C-1 reacts with water and ammonia to produce the ylide-like intermediates H2C-OH2 and H2C-NH3, which in turn undergo 1,2-hydrogen shift to produce methanol and methylamine, respectively. Results obtained indicate that in the gas phase, the ylides and the transition states are located below the reactants' energy levels. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 110: 1310-1316, 2010