Hydrogen bond is one of the most important non covalent interactions,
which plays key roles in molecular recognition, crystal
engineering, supra molecular assembly, materials science, and biological
systems [11–14]. Mostly the molecular recognitions are
concerned with strong NAH X and OAH X (X = O, N) hydrogen
bonds. Besides these conventional hydrogen bonds, unconventional
CAH O hydrogen bonds are also involved in the formation
of supra molecular assembly [15,16]. Crystallographic and abinitio
quantum chemical calculations, over the last decade, have also
established the proton donating ability of a methyl group and formation
of a weak hydrogen bonding type CAH X (X = O, N) bonds