title: Crystal growth, characterization and theoretical studies of 4-aminopyridinium picrate.
abstract: Single crystals of 4-aminopyridinium picrate (APP) were grown by slow evaporation of a mixed solvent system methanol-acetone (1:1, v/v) containing equimolar quantities of 4-aminopyridine and picric acid. Structure is elucidated by single crystal XRD analysis and the crystal belongs to monoclinic system with four molecules in the unit cell (space group P21/c) and the cell parameter values are, a=8.513 Å (±0.015), b=11.33 Å (±0.02), c=14.33 Å (±0.03) and β=104.15° (±0.019), V=1340 A(3) (±6) with refined R factors R1=0.0053 and wR2=0.0126. The electron density mapping is interpreted to find coordinates for each atom in the crystallized molecules. The various functional groups present in the molecule are confirmed by FT-IR analysis. UV-visible spectral analysis was used to determine the band gap energy of 4-aminopyridinium picrate. Powder X-ray diffraction pattern reveals the crystallinity of the as-grown crystal and it closely resembles the simulated XRD from the single crystal XRD analysis. Scanning electron microscopy reveals the surface morphology of the grown crystal. Optimized geometry is derived by Hartree-Fock theory calculations and the first-order molecular hyperpolarizability (β), theoretically calculated bond length, bond angles and excited state energy from theoretical UV-vis spectrum were estimated.
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608 002, India.
authors.forename: A
authors.initials: A
authors.lastname: Aditya Prasad
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608 002, India.
authors.forename: K
authors.initials: K
authors.lastname: Muthu
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608 002, India.
authors.forename: M
authors.initials: M
authors.lastname: Rajasekar
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608 002, India.
authors.forename: V
authors.initials: V
authors.lastname: Meenatchi
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608 002, India. Electronic address: aumats2009@gmail.com.
authors.forename: S P
authors.initials: SP
authors.lastname: Meenakshisundaram
mesh_terms: D003198:Computer Simulation; D003460:Crystallization; D004583:Electrons; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D010851:Picrates / Q000737:chemistry*; D011208:Powders; D011726:Pyridinium Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D014961:X-Ray Diffraction
chemical_list: C000598768:4-aminopyridinium picrate; D010851:Picrates; D011208:Powders; D011726:Pyridinium Compounds; C005858:picric acid
keywords: Crystal growth; FT-IR; HOMO–LUMO; Hyperpolarizability; Organic picrate