Electronic properties of the (Cr(Phen) 3)3+ Complex.

MAXI A. BURGOS PACI; GERARDO ARGÜELLO; ANGEL ANZANI

Mendoza

Encuentro; 9th International meeting on photodynamics and related aspects; 2016

Universidad de Tandil

P { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 10); line-height: 120%; text-align: left; }P.western { font-family: "Liberation Serif",serif; font-size: 12pt; }P.cjk { font-family: "Droid Sans Fallback"; font-size: 12pt; }P.ctl { font-family: "FreeSans"; font-size: 12pt; }A.western:link { }A.cjk:link { }A.ctl:link { }Theproperties of Chromium complexes like (Cr(NN)3)3+(NN=alfa-diimine ligands), have been little studied using electronicstructure methods, which are very useful to understand sprectroscopicand structural properties. Research on photophysical andphotochemical propierties of complexes of Cr(III) have been basedprimarily on qualitative aplications of ligand field theory whiletheorical studies based on methods such as Density Functional Theory(DFT) are little used. Inthis work, we present the simulation and characterization of theelectronic states of this complex using ab-initio theorical methods.In addition, electron transfer reactions between the(Cr(Phen)3)3+complexwith organic molecules of environmentalinterestin solution are presented. DFTand time-dependent DFT calculations of ground and excited states werecarried out using of the three-parameter hybrid functional developedby Becke in conjunction with the LYP exchange potential (B3LYP) withthe 6-311G** basis set. The relevant excited states involved in thephotoemissions process and electron transfer reactions have beencharacterized using the same method. Absorptionspectra was simulated using the energies of the vertical transitionsand the corresponding oscillator forces in the 250-550 nm range. Itis observed that the main spectral features are predicted to greataccuracy, both in position and relative intensities. Besides, thesimulations show several states of very low transtion probabilitiesthat would be difficult to reach with experimental conventionalexcitation sources.Electrontransfer reactions between (2T/2E)(Cr(Phen)3)3+with phenols were studied using stationary and time-resolvedmethodologies. Stationary fluorescence spectra were recorded using acommercial fluorometer (PTI) and time resolved fluorescence decaywere acquired using the 355 nm output of a tripled Nd-YAG laser(Brillant B, Quantel, 5ns pulse width). Bimolecular quenchingconstants were measured from standard Stern-Volmer plots.