scholarly journals Synthesis, Effect of Solvents on Electronic Absorption Spectra and Antimicrobial Activity of Some Histidine Complexes

2021 ◽  
Vol 11 (2) ◽  
Keyword(s):  
Antimicrobial Activity ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Effect Of Solvents

scholarly journals TD-DFT calculations, electronic structure, natural bond orbital analysis, nonlinear optical properties electronic absorption spectra and antimicrobial activity application of new bis-spiropipridinon/pyrazole derivatives

2018 ◽  
Vol 9 (4) ◽  
pp. 287-302
Author(s):  
Shimaa Abdel Halim
Keyword(s):  
Antimicrobial Activity ◽  
Optical Properties ◽  
Electronic Structure ◽  
Dft Calculations ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Nonlinear Optical ◽  
Electronic Absorption Spectra ◽  
Polarizable Continuum Model ◽  
Nonlinear Optical Properties

A new bis-spiropipridinon/pyrazole compound and some of its derivatives are characterized in terms of several theoretical parameters such as density of states (DOS), molecular electrostatic potentials (MEPs), non-linear optical (NLO) properties and electrophilicity. The electronic structure and nonlinear optical properties of the studied compounds 1-5 are investigated theoretically at the DFT-B3LYP/6-311G(d,p) level of theory. The effect of substituents of different strengths on the geometry and energetic are analyzed and discussed. The static dipole moment (µ), polarizability (α), anisotropy polarizability (Δα), and first order hyperpolarizability (βtot), are parameters for NLO of the studied compounds have been calculated at the same level of theory and compared with the prototype para-nitro-aniline (PNA). The electronic absorption spectra of the studied compounds are recorded in the UV-VIS region, in both ethanol and dioxane solvents. The theoretical spectra computed at a new hybrid exchange-correlation functional using the Coulomb-attenuating method (CAM-B3LYP) at the 6-311G(d,p) bases set in gas phase and with the polarizable continuum model (PCM) in dioxane and ethanol indicate a good agreement with the observed spectra. The antimicrobial activity for studied compounds was investigated. The antimicrobial activity results revealed that compound 4 has a good potency against Gram positive bacteria (E. coli) and Gram negative bacteria (P. vulgaris) in comparison with doxymycin standard. The structure activity relationship SAR has been studied for the studied compounds by DFT calculations, moreover, confirmed practical antimicrobial  activity results.

Stereochemistry of [carbonato-bis((S)-prolinato)]cobaltate(III) anion

1984 ◽  
Vol 49 (3) ◽  
pp. 680-683 ◽  
Author(s):  
Bohumil Hájek ◽  
Dagmar Sýkorová ◽  
Jiří Chyba
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Cd Spectra

The λ-C1-cis(N), δ-C1-cis(N), λ-C2-cis(N) and δ-C2-cis(N) isomers of the complex K[Co((S)-Pro)2CO3] were chromatographically separated and characterized by their electronic absorption spectra and CD spectra.

Photocolouration of 2,4,4,6-Tetraaryl-4H-pyrans and Their Heteroanalogues: Importance of Hypervalent Photoisomers

1995 ◽  
Vol 60 (10) ◽  
pp. 1621-1633 ◽  
Author(s):  
Stanislav Böhm ◽  
Mojmír Adamec ◽  
Stanislav Nešpůrek ◽  
Josef Kuthan
Keyword(s):  
Reaction Kinetics ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Theoretical Data ◽  
Order Reaction ◽  
Bleaching Process ◽  
First Order ◽  
Photodegradation Products ◽  
Hypervalent Molecules

Molecular geometries of 2,4,4,6-tetraphenyl-4H-pyran (Ia), 4,4-(biphenyl-2,2e-diyl)-2,6-diphenyl-4H-pyran (Ib) and their heterocyclic isomers II-V were optimized by the PM3 method and used for the calculation of electronic absorption spectra by the CNDO/S-CI procedure. Comparison of the theoretical data with experimental UV-VIS absorption spectra made possible to select hypervalent molecules IIIa, IIIb, IVa and IVb being responsible for the photocolouration of 4H-pyrans Ia, Ib, while compounds Va, Vb, VI and VII come into account as possible photodegradation products. The bleaching process of the UV illuminated compound Ia is analyzed in terms of dispersive first-order reaction kinetics.

Niobocene Dichloride and Niobocene Diiodide: Electronic Absorption Spectra and Electron Spin Resonance

1998 ◽  
Vol 63 (5) ◽  
pp. 628-635 ◽  
Author(s):  
Jana Holubová ◽  
Zdeněk Černošek ◽  
Ivan Pavlík
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Point Group ◽  
Esr Spectra ◽  
Ligand Field ◽  
Orbital Interaction ◽  
Symmetry Point Group ◽  
Spin Orbital ◽  
Halide Ligands

The effect of the halide ligand on the bonding of niobium in niobocene dichloride and niobocene diiodide was investigated. The electronic absorption spectra of the two compounds in the range of d-d transitions were resolved into four bands corresponding to transitions of the d1 electron between five frontier orbitals in a molecule of symmetry point group C2v. The energies of the frontier molecular orbitals were determined relatively to the energy of the orbitals in the spherically symmetric ligand field formed by the appropriate halide ligands. The effect of the halide ligands on the spin-orbital interaction of the HOMO orbital is discussed qualitatively on the basis the ESR spectra.

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