Crystal structure, IR-LD spectroscopic, theoretical and vibrational analysis of valinamide ester amide of squaric acid diethyl ester

Valinamide ester amide of squaric acid has been synthesized and structurally characterized by single crystal X-ray diffraction. Individual molecules are linked into zig-zag helix chains running parallel to [ 0 1 0] by N - H center dot center dot center dot O hydrogen bonds of length 2.7908( 19) angstrom and 2.980( 2) angstrom involving the valinamide nitrogen atoms and the amide carbonyl oxygen atom. An experimental IR spectroscopic characterization and theoretical vibrational analysis have also been performed, using the possibilities of polarized lineardichroic IR-spectroscopy (IR-LD), based on an orientation technique of the molecules as a suspension in a nematic liquid crystal.