The electronic spectra of the bis(dithiocarbamate) chelates of Cu(II) and Zn(II)

1982 ◽  
Vol 47 (11) ◽  
pp. 2867-2875 ◽  
Author(s):  
Drahomír Oktavec ◽  
Jozef Štefanec ◽  
Bohumil Síleš ◽  
Ernest Beinrohr ◽  
Václav Konečný ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Absorption Spectra ◽  
Electronic Spectra ◽  
Alkyl Chain ◽  
Solvent Polarity ◽  
Blue Shift ◽  
Red Shift

This work deals with the synthesis of dithiocarbamate chelates of Cu(II) and Zn(II) with ligands derived from dimethyl-, diethyl-, dipropyl-, dibutyl- and methylisopropylamine, piperidine and morpholine and the electronic spectra of these substances in the UV and visible regions. The absorption spectra of the cupric (and zinc(II)) chelates contain a single analytically important band around 270 (260) nm, assigned to the π-π* transition within the ligand, that is affected by the substituent on the nitrogen atom and the solvent polarity. Lengthening of the alkyl chain leads to increased intensity of the bands and a red shift of their λmax; increased solvent polarity leads to increased intensity of the bands and a blue shift.

The electronic spectra of nickel(II) bis(dithiocarbamate) chelates

1980 ◽  
Vol 45 (3) ◽  
pp. 791-799 ◽  
Author(s):  
Drahomír Oktavec ◽  
Bohumil Síleš ◽  
Jozef Štefanec ◽  
Elena Korgová ◽  
Ján Garaj
Keyword(s):  
Charge Transfer ◽  
Nitrogen Atom ◽  
Electronic Spectra ◽  
Alkyl Chain ◽  
Solvent Polarity ◽  
Blue Shift ◽  
Red Shift ◽  
Band Intensity ◽  
Absorption Bands

The synthesis and electronic spectra of the chelates of nickel(II) dithiocarbamates with ligands derived from dimethyl-, diethyl-, dipropyl-, dibutyl-, dipentyl-, dihexyl-, diheptyl-, dioctyl-, diisopropyl-, methylisopropylamine, piperidine, morpholine and piperazine are discussed. The absorption bands in the chelate spectra around 220 and 245 nm are assigned to absorption localized primarily in the S-C=S and N-C=S ligand groups. The analytically most important band with λmax around 330 nm assigned to M-L charge transfer is affected by alkyl substituents on the nitrogen atom and by the solvent polarity. The lengthening of the alkyl chain causes the increase in the intensity of the band and red-shift of its λmax; the increase of the polarity of the solvent leads to an increase in the band intensity and a blue shift.

Electronic spectra of salts of dithiocarbamic acids

1979 ◽  
Vol 44 (8) ◽  
pp. 2487-2493 ◽  
Author(s):  
Drahomír Oktavec ◽  
Jozef Štefanec ◽  
Bohumil Síleš ◽  
Václav Konečný ◽  
Ján Garaj
Keyword(s):  
Absorption Band ◽  
Electronic Spectra ◽  
Alkyl Chain ◽  
Carbon Disulphide ◽  
Blue Shift ◽  
Uv Spectra ◽  
Red Shift ◽  
Ammonium Salts ◽  
Absorption Bands

The report gives synthesis and UV spectra of a series of alkali and ammonium salts of the dithiocarbamic acids derived from dimethyl-, diethyl-, dipropyl-, dibutyl-, dipentyl-, dihexyl-, diheptyl-, dioctyl-, diisopropyl-, diisobutyl-, methylisopropylamine, piperidine, morpholine, piperazine and pyrrolidine. The absorption bands due to transitions localized in the groups CSS (λmax ~ 260 nm) and NCS (λmax ~ 280 nm) show a red shift with increasing length of the alkyl chain. Increasing polarity of solvent causes, with some of the compounds, a small red shift of λmax of the band due to CSS group, but it causes a considerable blue shift of λmax of the band due to NCS group in all the studied compounds. The absorption band near 207 nm is ascribed to the carbon disulphide produced by decomposition of the dithiocarbamates.

Catalytic Oxidation of 2-Mercaptoethanol by Cationic Water-soluble Phthalocyaninatocobalt(II) Complexes

1997 ◽  
Vol 01 (04) ◽  
pp. 309-313 ◽  
Author(s):  
MUTSUMI KIMURA ◽  
YUJI YAMAGUCHI ◽  
TOSHIKI KOYAMA ◽  
KENJI HANABUSA ◽  
HIROFUSA SHIRAI
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Absorption Spectra ◽  
Positive Charge ◽  
Alkyl Chain ◽  
Solvent Polarity ◽  
Water Soluble ◽  
Uv Absorption Spectra ◽  
Alkyl Chains ◽  
The Stability

The cationic amphiphilic cobalt(II) phthalocyanines have been prepared, and are characterized by UV-absorption spectra in water and organic solvents and in their mixtures. The monomer–dimer transformation equilibrium was affected by solvent polarity and the length of the alkyl chains in the amphiphilic parts. All complexes are efficient catalysts for the oxidation of 2-mercaptoethanol in the presence of dioxygen. The positive charge around the complex increases the acceleration of the dissociation of 2-mercaptoethanol under neutral pH. The catalytic activity is affected by the length of the alkyl chain; consequently the stability of aggregation between cobalt(II) phthalocyanines, as catalysts for the oxidation of 2-mercaptoethanol, can be changed.

Quinoline-annulated chlorins and chlorin-analogs

2016 ◽  
Vol 20 (01n04) ◽  
pp. 265-273 ◽  
Author(s):  
Joshua Akhigbe ◽  
Mengxi Yang ◽  
Michael Luciano ◽  
Christian Brückner
Keyword(s):  
Absorption Spectra ◽  
Functional Group ◽  
Bathochromic Shift ◽  
Red Shift ◽  
Simple Strategy

The OsO4-mediated dihydroxylation of quinoline-annulated porphyrin generates a quinoline-annulated dihydroxychlorin in a regioselective fashion. Its dihydroxypyrroline moiety, located at the opposite of the annulated pyrrole, is susceptible to the same functional group interconversions we previously demonstrated for non-annulated dihydroxychlorins: oxidations to the corresponding dione, lactone, and dialkoxymorpholine derivatives. The quinoline-annulated chlorin and derivatives are all characterized by absorption spectra that are much broadened and between 130 and 220 nm red-shifted compared to their non-annulated analogs. Absorbance maxima in the NIR up to well above 800 nm were recorded. We attribute the bathochromic shift to their extended [Formula: see text]-systems and inferred non-planarity, highlighting that quinoline-annulation is a particularly effective and simple strategy to red-shift the absorption spectra of chlorins and chlorin analogs.

Unusual spectral shifts in the prototropic reactions of 2,7-diaminofluorene

1987 ◽  
Vol 65 (9) ◽  
pp. 2013-2018 ◽  
Author(s):  
R. Manoharan ◽  
Sneh K. Dogra
Keyword(s):  
Absorption Spectrum ◽  
Aqueous Medium ◽  
Fluorescence Spectrum ◽  
Blue Shift ◽  
Proton Donor ◽  
Red Shift ◽  
The Other ◽  
Spectral Shifts ◽  
Other Hand

The red shift observed in the absorption spectrum of 2,7-diaminofluorene (DAF) in ether and acetonitrile is either due to the proton-donating capacity of the solute or due to its dispersive interactions with the solvent and a blue shift in methanol and water is due to the proton-accepting nature of DAF. DAF acts as a proton donor in S1 state in all solvents. The red shift in the fluorescence spectrum of the monocation of DAF relative to that of DAF is not because of the —NH2 group becoming more basic but because of the large solvent relaxating in aqueous medium. On the other hand, the monocation of DAF in cyclohexane follows the normal blue shift in the fluorescence spectrum. pKa values for the various prototropic reactions in S0 and S1 states are determined and discussed.

scholarly journals Spectral properties of coumarin derivatives in various environments

2013 ◽  
Vol 11 (4) ◽  
pp. 492-501 ◽  
Author(s):  
Alzbeta Holubekova ◽  
Pavel Mach ◽  
Jan Urban
Keyword(s):  
Gas Phase ◽  
Absorption Spectra ◽  
Spectral Properties ◽  
Density Functional ◽  
Water Solution ◽  
Blue Shift ◽  
Coumarin Derivatives ◽  
Complex Environments ◽  
Td Dft ◽  
Solvent Environment

AbstractThe structural and spectral properties of coumarin derivatives in complex environments were investigated within the time-dependent density functional theory (TD DFT). Absorption spectra calculations were obtained at TD PBE0/6-31+G(d,p) level of theory for coumarin47 in the gas-phase and in various polar and non-polar organic solvents. The geometries of coumarins 6, 30, 47 and 522 in the gas phase and in inclusion complexes with the β-cyclodextrin (βCD) were determined by PM3 and DFT (HCTH/6-31G) calculations. Encapsulation of coumarin in βCD and associated changes in electronic structure produced either a red or blue shift in the absorption spectra of coumarins. A proposed cavity model for βCD-coumarin complex in water solution allowed identification of various contributions to the overall shift in the absorption spectra of coumarin upon complex formation in a solvent environment

scholarly journals Impact of Solvents, Magnesium Oxide and Aluminium Oxide Nanoparticles on the Photophysical Properties of Acridine Orange Dye

2021 ◽  
pp. 1-7
Author(s):  
Fairooz Kareem ◽  
Mahasin Al-Kadhemy ◽  
Asrar Saeed
Keyword(s):  
Acridine Orange ◽  
Magnesium Oxide ◽  
Fluorescence Spectra ◽  
Aluminium Oxide ◽  
Blue Shift ◽  
Red Shift ◽  
Oxide Nanoparticles ◽  
Absorption And Fluorescence Spectra ◽  
Aluminium Oxide Nanoparticles ◽  
Al2o3 Nps

Absorption and fluorescence spectroscopy techniques were applied to investigate the photophysical characteristics of acridine orange (AO) dye in solvents that included distilled water, dimethyl sulfoxide (DMSO), acetone and ethanol in various concentrations (1×10-4–1×10-6) M. All of the samples were served at room temperature. The relationships between various parameters describing the strength of optical transitions in atoms and molecules were reviewed. This study expresses various viewpoints by describing how concentration and solvent affect the dye's absorption and fluorescence spectra. The absorption spectra of AO exhibit a band at (490 nm), except for DMSO, which shifts more towards red by 5 nm. The fluorescence spectra show a blue shift in AO aqueous solution around 6 nm until (0.5×10-4) M, followed by a red shift at around 7 nm at (1×10-6) M. There is a blue shift in (1×10-5) M for DMSO at around 4 nm, then a 10 nm red shift in higher concentrations as well as a 9 nm red shift in acetone and 6 nm in ethanol. Adding magnesium oxide nanoparticles (MgO NPs) quenched AO in both absorption and fluorescence spectra, whereas maximum fluorescence and intensity increased when aluminium oxide nanoparticles (Al2O3 NPs) were added to the solution. KEYWORDS Laser dye, absorption spectrum, fluorescence spectrum, MgO NPs, Al2O3 NPs

scholarly journals Interaction Mechanism between Antibiotics and Humic Acid by UV-Vis Spectrometry

2018 ◽  
Vol 15 (9) ◽  
pp. 1911 ◽  
Author(s):  
Xiaoyu Yuan ◽  
Shengke Yang ◽  
Jie Fang ◽  
Xueli Wang ◽  
Haizhen Ma ◽  
...  
Keyword(s):  
Humic Acid ◽  
Absorption Band ◽  
Interaction Mechanism ◽  
Blue Shift ◽  
Degree Of Polymerization ◽  
Ultraviolet Spectrum ◽  
Red Shift ◽  
Vis Spectroscopy ◽  
Nm Range ◽  
Peak Value

In this study, the interaction between the humus and two antibiotics was studied by UV-Vis spectroscopy to describe the interaction mechanism and the effects of different environmental factors on the mechanism. Results showed that humic acid (HA) containing more aromatic groups was easily associated with antibiotics. In the HA-OTC, with the increase of the concentration of OTC, there were obvious absorption peaks in the 230–260 nm and 330–360 nm range, and the absorption band of the HA ultraviolet spectrum underwent a slight blue shift and the absorption intensity increased, demonstrating that a new ground state complex was generated. In the HA-SD, with the increase of SD concentration, an aromatic structure absorption peak appeared in the 190–220 nm range, and the peak value increased and the absorption band underwent a red shift, and the aromatization of HA decreased, which enhanced the interaction between the antibiotics and HA. With the increase of pH, the absorption band of HA, HA-OTC and HA-SD ultraviolet spectrum suffered a blue shift, the degree of polymerization of HA molecules decreased, and the number of adsorption binding sites increased, which resulted in the interaction of HA with antibiotics being enhanced. The absorption band of HA, HA-OTC and HA-SD displayed a red shift with the increase of ionic strength, which indicated that the repulsion within HA particles was weakened, and the molecular polymerization was strengthened and therefore, the interaction between antibiotics and HA was inhibited. The UV characteristics of the HA, HA-OTC and HA-SD systems were insensitive to the temperature. This study lays the foundation for better studying the effect of humus on the distribution of antibiotic residues in the environment.

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