Spectroscopic studies, molecular structure and hydrogen bonding in hydrates of Gemini betaines

In the present study, two flexible Gemini betaines are synthesized, N,N′-dicarboxymethyl-N,N,N′,N′-tetramethyl-1,3-propanediammonium trihydrate (1) and N,N′-dicarboxymethyl-N,N,N′,N′-tetramethylethylenediammonium dihydrate (2). fect of water molecules on the structure, conformation and hydrogen bonds of the Gemini compounds in solid state and solutions were studied by FTIR, 1H and 13C NMR spectra and B3LYP calculations and compared with results of X-ray diffraction. reening constants for 13C and 1H atoms have been calculated by the GIAO/B3LYP/6-31G(d,p) approach and analyzed. Linear correlations between the experimental 1H and 13C chemical shifts and the computed screening constants confirm the optimized geometry. The optimized bond lengths, bond angles and torsion angles calculated by B3LYP/6-31G(d,p) approach have been compared with the X-ray data. A force field calculation was performed on the minimum energy geometry. Vibrational wavenumbers and infrared intensities was predicted.