A theoretical study of the effects of polar substitution on the activation barriers for internal rotation around the C-N bond in p-substituted nitrosobenzenes: comparison of DFT and MP2 calculations

Authors : Şafak Özhan Kocakaya And Necmettin PİRİNÇÇİOĞLU

Pages : 399-410

Doi:10.3906/sag-1205-27

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The activation barriers for internal rotation around the C-N bond in p-substituted nitrosobenzenes were calculated using the density functional theory insert ignore into journalissuearticles values(DFT); and second-order Møller-Plesset insert ignore into journalissuearticles values(MP2); methods with the 6-31+ginsert ignore into journalissuearticles values(d); basis set. The polarisable continuum model insert ignore into journalissuearticles values(PCM); was used to model the solvent effect. An explicit water molecule was also introduced to form a hydrogen bond with the nitrosogroup and its effect on the barrier was studied by DFT. The barriers were well-correlated with Hammett sigma+ rather than sigma values, meaning a strong resonance effect. The MP2 method produces better and comparable results with the few available experimental values.
Keywords : Para substituted nitrosobenzenes, C N bond rotation, polar substituent effect, molecular modelling DFT, MP2, PCM