6 research outputs found
Theoretical understanding of the increment of upon protonation of pyridine peripheral octupolar molecules: Toward nonlinear optical sensors
6 pages, 6 tables, 4 figures.In this article, we present a computational study of the nonlinear optical properties of pyridine-based
octupolar molecules in their neutral and fully triprotonated states. The effect of the core substitution
and the degree of conjugation with the periphery has been also established and confirms the
possibility of fine-tuning the nonlinear optical response. Computations involving the time-dependent
density-functional theory approach serve to further explore the existence of excited states with
nonzero dipole moment. From these results, the origin of the high second-order nonlinear optical
activity upon protonation is addressed.The present work was supported in part by the Dirección
General de Enseñanza Superior DGES, MEC, Spain
through research Project Nos. CTQ2006-14987-C02-01 and
CTQ2005-01368. The authors are also indebted to Junta de
Andalucía and Gobierno de Aragón Spain for funding their
research groups FQM-0159 and E39. M.C.R.D. is grateful to
the MEC/Fulbright for her Postdoctoral Fellowship at the
Georgia Institute of Techology. J.C. is grateful to the MEC of
Spain for an I3 professorship position of Chemistry at the
University of Málaga and M.M.O. acknowledges the MEC
for a personal grant.Peer reviewe
Theoretical understanding of the increment of upon protonation of pyridine peripheral octupolar molecules: Toward nonlinear optical sensors
6 pages, 6 tables, 4 figures.In this article, we present a computational study of the nonlinear optical properties of pyridine-based
octupolar molecules in their neutral and fully triprotonated states. The effect of the core substitution
and the degree of conjugation with the periphery has been also established and confirms the
possibility of fine-tuning the nonlinear optical response. Computations involving the time-dependent
density-functional theory approach serve to further explore the existence of excited states with
nonzero dipole moment. From these results, the origin of the high second-order nonlinear optical
activity upon protonation is addressed.The present work was supported in part by the Dirección
General de Enseñanza Superior DGES, MEC, Spain
through research Project Nos. CTQ2006-14987-C02-01 and
CTQ2005-01368. The authors are also indebted to Junta de
Andalucía and Gobierno de Aragón Spain for funding their
research groups FQM-0159 and E39. M.C.R.D. is grateful to
the MEC/Fulbright for her Postdoctoral Fellowship at the
Georgia Institute of Techology. J.C. is grateful to the MEC of
Spain for an I3 professorship position of Chemistry at the
University of Málaga and M.M.O. acknowledges the MEC
for a personal grant.Peer reviewe
Vibrational fingerprint of the structural tuning in push-pull organic chromophores with quinoid or proaromatic spacers
The Raman spectra of a series of push-pull molecules containing probenzenoid or quinoid spacers which are substituted with 1,3-dithiol-2-ylidene as donor and dicyano-methylene or barbituric acid as acceptors have been analyzed. The experimental spectra have been assigned and interpreted according to density functional theory calculations. Correlations between the Raman spectra of the isolated spacers and of the substituted molecules have been done. Raman bands in the 1620-1560 cm-1 interval provide vibrational markers of the quinoidaromatic structural evolution. This finding is supported by a careful inspection of geometrical parameters, namely, bond length alteration data and particular bond distances. As a result, the peak positions and relative intensities of these Raman features can be used to evaluate the benzenoid character of the spacer as a function of the donor/acceptor substitution pattern. This paper shows that Raman spectroscopy is a powerful spectroscopic tool for the analysis of the conjugational properties (i.e., intramolecular donor-->acceptor charge transfer) of new organic materials.Peer reviewe