Study of the hydrogen bonding interaction of 1:1 complexes of serine with formamide using density functional theory

The hydrogen bonding of 1:1 complexes formed between formamide and serine molecules has been completely investigated in the present study using density functional theory (DFT) method at varied basis set levels from 6-31G to 6-311++G(d,p). Fifteen reasonable geometries on the potential energy hypersurface of formamide and serine system are considered with the global minimum, 13 of them are cyclic double-hydrogen bonded structures and the other two are one-hydrogen bonded structures. The optimized geometric parameters and interaction energies for various isomers at different levels are estimated. The infrared spectrum frequencies, IR intensities and the vibrational frequency shifts are reported.