The investigation of transition state in the conversion of 3-cyclopropylmethoxy-3- chloro diazirine to various products by ab initio method

Optimized geometry and the corresponding electronic structure, vibrational frequencies and thermodynamic properties of cyclopropylmethoxychlorocarbene (cpmcc), 3- cyclopropylmethoxy-3-chlorodiazirine have been calculated using ab initio methods DFTB3LYP with 6-311++G** basis set. Results show that cpmcc is transition state with a first order TS saddle point. The displacement matrix of the negative mode of vibration of the TS specie shows that the reaction path follows in the direction of the elimination of the CO group which is consistent with the mechanism proposed upon experimental data. Calculations were also carried out for reactants and products at the same levels of theory. Nuclear quadrupole coupling constants (NQCC), χ, and asymmetry parameter, η, of the 2H, 35Cl nuclei have been calculated for reactants, transition states and products.