Solid state synthesis, crystal growth, atomic packing and physicochemical studies of (E)-2-cyano-3-(3-hydroxyphenyl)acrylamide

The organic crystalline species (E)-2-cyano-3-(3-hydroxyphenyl)acrylamide has been synthesized by solid state reaction between 3-hydroxy benzaldehyde (HB) and 2-cyanoacetamide (CA). The molar ratio of HB and CA forming this new organic entity was found to be 1:1, established with the help of phase diagram study and single crystal XRD analysis. The phase diagram established between HB and CA shows the formation of a new compound surrounded by two eutectics on either side of the compound. Thermal properties such as heat of fusion, entropy of fusion, interfacial energy, and excess thermodynamic functions of the title compound and both eutectics are studied and reported, in addition to a DSC study to analyze the thermal behavior. A large and transparent single crystal with dimensions of 19×7×2 mm3 of this newly synthesized compound was grown from the saturated solution of a mixed solvent, employing the slow cooling technique. The single crystal X-ray diffraction analysis showed that the compound crystallizes in the monoclinic system (space group P21/n) with a=9.031(2) Å, b=5.178(2) Å, c=18.330(4) Å, and β=90.86(3)° and comprises dimers of symmetry-related molecules, connected to each other via strong OH···O bonds.

► A complex of 3-hydroxybenzaldehyde and 2-cyanoacetamide was synthesized.
► The crystal was synthesized by solid state reaction.
► We discuss solubility in different solvents, thermal properties, and phase diagram.
► A large crystal was grown from a solution of mixed solvents in optimized composition.
► The crystal and molecular structure was determined by single crystal XRD.