Probing the influence of solvent effects on the conformational behavior of 1,4-diazacyclohexane systems

Structural and energetic consequences of replacing one or more carbon atoms in small cyclic hydrocarbons with electronegative atoms have been observed due to stereoelectronic anomeric and gauche effects. We have reported the influence of gauche effect on the conformational behavior of a 1,4-diazacyclohexane system using the DFT B3LYP/6-311 + G** level of theory. Factors which are found to control the conformational preferences of a 1,4-diazacyclohexane system include steric, dipolar repulsions and hyperconjugative interactions. The stability order of the 1,4-diazacyclohexane conformers was predicted to be similar in the gas phase and solvent continuum model (aqueous phase). The interactions of explicit water molecules with 1,4-diazacyclohexane conformers however predicted a different order of stability compared to the gas phase and continuum phase results. Ab initio molecular dynamics (AIMD) study showed the minor perturbation in the orientation of explicit water molecules compared to the DFT results and no dramatic changes was observed during the simulation with 1,4-diazacyclohexane conformers.