title: Twisted intramolecular charge transfer and its contribution to the NLO activity of Diglycine Picrate: a vibrational spectroscopic study.
abstract: Single crystals of Diglycine Picrate (DGLP) were grown by slow evaporation technique and the vibrational spectral analysis is carried out using FT Raman and FT-IR spectroscopy, supported by Density Functional Theoretical (DFT) computations to derive equilibrium geometry, vibrational wavenumbers and first hyperpolarizability. The vibrational spectra confirm the existence of NH3(+) in DGLP. The influence of Twisted Intramolecular Charge Transfer (TICT) caused by the strong ionic ground state hydrogen bonding between charged species making DGLP crystal to have the non-centrosymmetric structure has been discussed. The Natural Bond Orbital (NBO) analysis confirms the occurrence of strong intermolecular N-H⋯O hydrogen bond. The HOMO-LUMO energy gap and the first order hyperpolarizability were calculated and it supports the nonlinear optical activity of the Diglycine Picrate crystal.
authors.affiliation: Department of Physics, Women's Christian College, Nagercoil 629001, India.
authors.forename: S
authors.initials: S
authors.lastname: Alen
authors.affiliation: Department of Physics, Bishop Moore College, Mavelikara, Alappuzha 690110, Kerala, India. Electronic address: dsajand@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Sajan
authors.affiliation: Department of Physics, Government Arts College for Women (Autonomous), Pudukottai, India.
authors.forename: T
authors.initials: T
authors.lastname: Umadevi
authors.affiliation: Charles University in Prague, Faculty of Science, Department of Inorganic Chemistry, Hlavova 8, 128 40 Prague 2, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Němec
authors.affiliation: Christian College, Kattakada, Trivandrum, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Baburaj
authors.affiliation: Department of Physics, Women's Christian College, Nagercoil 629001, India.
authors.forename: V
authors.initials: V
authors.lastname: Bena Jothy
authors.affiliation: Christian College, Kattakada, Trivandrum, India.
authors.forename: B H
authors.initials: BH
authors.lastname: Selin Joy
mesh_terms: D003460:Crystallization; D004583:Electrons; D006860:Hydrogen Bonding; D008968:Molecular Conformation; D017711:Nonlinear Dynamics; D055620:Optical Phenomena; D010851:Picrates / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D010851:Picrates; C005858:picric acid
keywords: DGLP; FT-IR; FT-Raman; ICT; NBO