ON THE NATURE OF ARYLSULFIDE AND ARYLSELENIDE DIMMER RADICAL CATIONS

Carlos paz

Congreso; 13th Latin American Conference on Physical Organic Chemistry; 2015

Comité Organizador de 13th Latin American Conference on Physical Organic Chemistry

In the present work, the formation ofdifferent dimmers of ArSCH3 and ArSeCH3 radical cations ([R2ZZR2]+?, Z=S, Se)were studied by means of DFT calculations. Sawaki, et al [1], employed the BLYPmethod, obtaining three conformers, of the dimmer [Ar(CH3)SSAr(CH3)]+?,  with similar energies of formation and aforth less stable conformer. However, BLYP is not the appropriate functionalfor dealing with these kind of complexes. By using the M062X functional, suitedfor working with complexes with s-p, p-p interactions, different energies wereobtained. The geometries are also different, with a SS 2c-3e bond shorter thanthe one reported in ref. [1]. In the case of selenium complexes, it was foundthat they are stronger as they present lower dimerization energies, alsoreflected in their higher dimerization equilibrium constant (Kdim).

[1] Yokoi, H.; Hatta, A.; Ishiguro,K.; Sawaki, Y. J. Am. Chem. Soc. 1998, 120,12728-12733.