Study of 5-azidomethyl-8-hydroxyquinoline structure by X-ray diffraction and HF–DFT computational methods

5-Azidomethyl-8-hydroxyquinoline has been synthesized and characterized using IR, ¹H and ¹³C NMR spectroscopic methods. Thermal analysis revealed no solid-solid phase transitions. The crystal structure of this compound was refined by Rietveld method from powder X-ray diffraction data at 295 K. The single- crystal structure of the compound at 260 K was solved and refined using SHELX 97 program. According to the data obtained by both methods, the structure of the compound is monoclinic, space group P2₁/c, with Z = 4 and Z' = 1. For the single crystal at 260 K, a = 12.2879 (9) Å, b = 4.8782 (3) Å, c = 15.7423 (12) Å, β=100.807(14)°. Mechanisms of deformation resulting from intra- and intermolecular interactions, such as hydrogen bonding, induced slight torsions in the crystal structure. The optimized molecular geometry of 5-azidomethyl-8-hydroxyquinoline in the ground state is calculated using density functional theory (B3LYP) and Hartree-Fock (HF) methods with the 6-311G(d,p) basis set. The calculated results show good agreement with experimental values. Energy gap of the molecule was found using HOMO and LUMO calculation which reveals that charge transfer occurs within the molecule.

     

Study of the electronic transitions of azulene and several of it's derivitives and their auto-association by the monopole-dipole atomic interaction (AMDI) model

The corresponding hydrogen, carbon and nitrogen atomic dipolar polarisabilities and effective charges given by Fraga are used for the determination of theoretical UV absorption spectra of azulene, 1,3-diaza-azulene and 2-phenyl-1,3-diaza-azulene and their self-associations. These spectra are obtained for the first time using the atom monopole dipole interaction model and compared to those given experimentally by other authors.     

UV absorption spectra of 1,1'-binaphtyle and 2,2'-binaphtyle molecules and their self-associations from the atom monopole-dipole interaction (AMDI) model

The Atom Monopole-Dipole interaction (AMDI) model is used for the first time in calculation of UV absorption spectra of 1,1'-binaphtyl and 2,2'-binaphtyl and their self-associations for the case of frequency-dependant atom polarisability with Lorentzian band shape. UV absorption spectra are obtained from a set of electronic normal modes. The variation of spectra with the conformation of these molecules concord with the results of the medium effect on the corresponding electronic transitions. The calculated auto-association spectra are qualitatively in good agreement with polycyclic aromatic hydrocarbon aggregations behaviour.     

Theoretical simulation of UV absorption spectra of carbazole and some homocyclic analogs

The UV absorption spectra structures of carbazole, fluorene and dibenzofurane are studied using the atom monopole-dipole interaction (AMDI) model and atomic dipolar polarisabilities and effective charge given by Fraga. The absorption spectra corresponding to these molecules and their self-associations are presented. The original obtained results are discussed and compared to previous works.     

Piezoreflectance spectra of 1s Z12 exciton in CuBr

We have investigated the piezoreflectance spectra (deltaR/R) of the 1s Z12 exciton in single crystals of copper bromide CuBr at the temperature of 95 K with linearly polarized light. The spectra were successively studied with the pressure p along the [001] and [111] axis and the wave vector k of the incident light parallel to the [110] direction. The shear deformation potentials b and d of the 1s Z12 exciton were deduced from the stress-induced shift and splitting. The results are compared with those obtained in other works.     

Experimental (X-ray Diffraction,UV–Vis Spectroscopy) and DFT Studies of 1-Ethyl-3-methylquinoxaline-2-thione

Russian Journal of Physical Chemistry A - In this paper, we present the experimental and theoretical investigation of 1-ethyl-3-methylquinoxaline-2-thione, molecule exhibiting an important...