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Computational Investigations of Iodine Oxides

1998; American Chemical Society; Volume: 102; Issue: 45 Linguagem: Inglês

10.1021/jp982708u

1520-5215

Ashutosh Misra, Paul Marshall,

Catalytic Processes in Materials Science

Isomers of IO2, I2O, and I2O2 have been characterized by ab initio methods. Vibrational frequencies and geometries were obtained at the MP2/6-31G(d) and MP2/6-311+G(3df) levels of theory, respectively. The thermochemistry was derived using approximate QCISD(T)/6-311+G(3df) (Gaussian-2) energies coupled with isodesmic reactions. Computed values of ΔfH298 for these molecules are the following (in kJ mol-1): OIO, 76.7; IOO, 96.6; IIO, 134.1; IOI, 92.4; IOOI, 156.8; IIO2, 103.0; IOIO, 124.2; OIIO, 224.0. Uncertainties are discussed in the text. The results are compared with some previous empirical estimates and are employed in a QRRK analysis to interpret the IO + IO reaction: favorable products include I + OIO.