Growth, crystal structure, thermal, spectral studies and density functional theory computational analysis of an organic nonlinear optical crystal: 2‐{3‐[2‐(4‐dimethylaminophenyl)vinyl]‐5,5‐dimethylcyclohex‐2‐enylidene}‐malonitrile

We report on synthesis, growth and characterization of an organic nonlinear optical (NLO) crystal 2‐{3‐[2‐(4‐dimethylaminophenylvinyl]‐5,5‐dimethylcyclohex‐2‐enylidene}‐malonitrile (DAT2). The functional groups are identified by 1H‐NMR. Large size single crystal of DAT2 of size 1.2 × 0.5 × 0.2 cm3 is grown for the first time using solution growth technique. The physicochemical properties of DAT2 crystal such as crystal structure, melting point, optical reflectance and photoluminescence are studied experimentally. Density functional theory (DFT) analysis is employed to study the band structure, optical and electronic properties of DAT2. The theoretical bandgap was compared with the experimental one. LDA approximation has been used to compare the GGA results. Organic NLO material DAT2 is synthesized and optical quality DAT2 single crystals are grown from slow evaporation process. The physicochemical properties are experimentally studied to understand the crystal structure, melting point etc., The electronic band structure and optical properties such as dielectric constant, refractive index, reflectivity are determined theoretically using DFT method.