0000000000471533

AUTHOR

L Moisés Canle

showing 2 related works from this author

Combined Theoretical and Experimental Study of the Photophysics of Asulam

2013

The photophysics of the neutral molecular form of the herbicide asulam has been described in a joint experimental and theoretical, at the CASPT2 level, study. The unique π → π* aromatic electronic transition (f, ca. 0.5) shows a weak red-shift as the polarity of the solvent is increased, whereas the fluorescence band undergoes larger red-shifts. Solvatochromic data point to higher dipole moment in the excited state than in the ground state (μ(g)μ(e)). The observed increase in pKa in the excited state (pKa* - pKa, ca. 3) is consistent with the results of the Kamlet-Abboud-Taft and Catalán et al. multiparametric approaches. Fluorescence quantum yield varies with the solvent, higher in water (…

LightEstat excitatAnalytical chemistryQuantum yieldElectrons1-PropanolFluorescenceMolecular electronic transitionWater PollutantsPhysical and Theoretical ChemistryPhotolysisAqueous solutionHerbicidesChemistryMethanolSolvatochromismWaterHydrogen-Ion ConcentrationFluorescenceFluorescènciaKineticsExcited stateSolventsQuantum TheoryThermodynamicsCarbamatesGround statePhosphorescenceFisicoquímica
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On the Low-Lying Excited States ofsym-Triazine-Based Herbicides

2005

We report a joint computational and luminescence study on the low-lying excited states of sym-triazines, namely, 1,3,5-triazine (1) and the ubiquitous herbicides atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (2)] and ametryn [6-methylthio-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (3)]. Geometrical structures, energetics, and transition and state properties of I and 2 were computed at the TD-DFT, CASSCF, and CASPT2 levels of theory. The fluorescence and phosphorescence emission spectra, lifetimes, and fluorescence quantum yields were measured for the three compounds, and from these, the energies of the lowest excited states and their corresponding radiative rates…

Absorption spectroscopyQuantum yieldPhotochemistryMolecular physicsAbsorptionAb initio quantum chemistry methodsOscillometryPressureRadiative transferEmission spectrumPhysical and Theoretical ChemistryMolecular StructureChemistry PhysicalHerbicidesTriazinesChemistryTemperatureHydrogen-Ion ConcentrationModels TheoreticalAtomic and Molecular Physics and OpticsSpectrometry FluorescenceModels ChemicalSpectrophotometryExcited stateAtrazineIndicators and ReagentsPhosphorescenceLuminescenceSoftwareChemPhysChem
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