Eric Perpète - Academia.edu (original) (raw)

Papers by Eric Perpète

Research paper thumbnail of Investigation of the complexation reaction between 2-diethylaminomethyl-4-methylphenol and ZnCl2. Reaction mechanism and solvent effects

Journal of Molecular Structure: THEOCHEM, 2006

ABSTRACT The reaction mechanism of the chemical reaction of 2-diethylaminomethyl-4-methylphenolat... more ABSTRACT The reaction mechanism of the chemical reaction of 2-diethylaminomethyl-4-methylphenolate with ZnCl2 is investigated by means of the PM3 semi-empirical method. We propose two different but competitive stepwise pathways going from the isolated reactants to the tetra-coordinated bidentate final complex, where the zinc atom is bonded both to the oxygen and to the nitrogen atom of the ligand. Each pathway proceeds via different monodentate intermediate complexes. This study shows that either the first chemical bond formed between ZnCl2 and 2-diethylaminomethyl-4-methylphenolate is the Zn–O bond or the Zn–N bond. The direct pathway going from the reactants to the final product through a concerted asynchronous mechanism is found to be unrealistic, since it involves a second order saddle point.Solvent effects are taken into account with the SCRF dielectric continuum model at the PM3 and (RHF/3-21G) levels of theory. This preliminary study shows that the complex formation is favored by the use of polar solvent.

Research paper thumbnail of Vibrational frequencies of H2O and CO2 from Car-Parrinello molecular dynamics

Journal of Molecular Structure: THEOCHEM, 1998

Using plane wave basis functions within the local density approximation, the Car-Parrinello molec... more Using plane wave basis functions within the local density approximation, the Car-Parrinello molecular dynamics scheme has been applied to evaluate the vibrational frequencies of the H2O and CO2 molecules. This dynamical approach using the plane wave basis set provides estimates of similar quality to standard density functional schemes using gaussian basis sets.

Research paper thumbnail of A TD-DFT investigation of the visible spectra of fluoro-anthraquinones

With ab initio computational chemistry techniques explicitly taking into account electron correla... more With ab initio computational chemistry techniques explicitly taking into account electron correlation and solvent effects, we investigate the chemical substitution impact on the l max of absorption, of 1,2,3,4-tetrafluoro-9,10-anthraquinone. Increasing the electron-donating strength of the auxochromic groups leads to bathochromic displacements. The largest bathochromic effect has been observed when four built-up hydrogen bonds interact with the C]O chromophores. For each substitution, the results are rationalized in terms of HOMO and LUMO energy levels, as well as in hydrogen bond effects on the charge separation and bond length in the chromophoric unit.

Research paper thumbnail of Simulation of the Properties of a Photochromic Triad

Journal of Physical Chemistry Letters, 2010

ABSTRACT

Research paper thumbnail of Ab Initio Investigation of the Electronic Properties of Coupled Dithienylethenes

Journal of Physical Chemistry Letters, 2010

The electronic structures and magnetism of the half-Heusler alloys XCrAl (X ¼ Fe, Co, Ni) and NiC... more The electronic structures and magnetism of the half-Heusler alloys XCrAl (X ¼ Fe, Co, Ni) and NiCrZ (Z ¼ Al, Ga, In) have been investigated to search for new candidate half-metallic materials. Here, we predict that NiCrAl, and NiCrGa and NiCrIn are possible halfmetals with an energy gap in the minority spin and a completely spin polarization at the Fermi level. The energy gap can be attributed to the covalent hybridization between the d states of the Ni and Cr atoms, which leads to the formation of bonding and antibonding peaks with a gap in between them. Their total magnetic moments are 1m B per unit cell; agree with the Slater-Pauling rule. The partial moment of Cr is largest in NiCrZ alloys and moments of Ni and Al are in antiferromagnetic alignment with Cr. Meanwhile, it is also found that FeCrAl is a normal ferromagnetic metal with a magnetic moment of 0.25m B per unit cell and CoCrAl is a semi-metal and non-magnetic. r

Research paper thumbnail of TD-DFT simulations of the electronic properties of star-shaped photochromes

Physical Chemistry Chemical Physics, 2010

We have investigated, with the help of time-dependent density functional theory, the UV/Vis absor... more We have investigated, with the help of time-dependent density functional theory, the UV/Vis absorption features of three diarylethenes coupled through a pi-electron rich moiety. For this star-shaped molecular architecture, the modifications of the electronic signatures induced by the ring-closure of one, two or three diarylethenes are carefully examined. The obtained theoretical results compare favorably with the available experimental data, and allow to reach conclusions helpful for the design of more efficient assemblies combining several molecular switches.

Research paper thumbnail of Doubly Closing or Not? Theoretical Analysis for Coupled Photochromes

Journal of Physical Chemistry C, 2010

ABSTRACT

Research paper thumbnail of A theoretical study of the perfluoro-diarylethenes electronic spectra

Journal of Photochemistry and Photobiology A-chemistry, 2008

Using a combination of the time-dependent density functional theory and the polarizable continuum... more Using a combination of the time-dependent density functional theory and the polarizable continuum model, we have investigated the visible spectra of 129 closed-ring perfluorocyclopentene diarylethenes, solvated in various environments (185 cases). The theoretical simulations are able to reproduce the major experimental trends, especially the auxochromic shifts though solvatochromic effects in protic media are not correctly modelled. A quantitative agreement, that

Research paper thumbnail of An ab initio study of the absorption spectra of indirubin, isoindigo, and related derivatives

The journal of physical chemistry. A, Jan 4, 2006

The UV/visible spectra of a series of indirubin, isoindigo, and other indigo/thioindigo related d... more The UV/visible spectra of a series of indirubin, isoindigo, and other indigo/thioindigo related dyes have been evaluated in various solvent environments by using the time-dependent density functional theory in conjunction with the polarizable continuum model. Even for molecules of the same family, significant differences in the excitation processes have been noted. Two hybrid functionals have been selected: B3LYP and PBE0. For a set of the 50 selected molecular cases, both functionals provide accurate lambda(max), with mean absolute deviations limited to 0.1 eV. Actually, isoindigo is the main challenging series, with systematically underestimated excitation energies, due to the different nature of the excitation process. In most cases, we found that PBE0 is more efficient in reproducing the experimental values than B3LYP for sulfur-containing dyes not featuring internal hydrogen bonds, the reverse assertion being also true. In addition, the spectra of a series of unknown dyes have ...

Research paper thumbnail of TD-DFT investigation of diarylethene dyes with cyclopentene, dihydrothiophene, and dihydropyrrole bridges

The journal of physical chemistry. A, Jan 28, 2007

We have investigated the visible spectra of closed-ring diarylethenes presenting cyclopentene, di... more We have investigated the visible spectra of closed-ring diarylethenes presenting cyclopentene, dihydrothiophene, and dihydropyrrole bridging structures. Our simulations have been performed with an ab initio time-dependent density functional theory approach that takes into account bulk environmental effects. The computed lambda(max) agree qualitatively with experiment, and once a simple statistical treatment is performed, a quantitative agreement is reached. Indeed, after linear fitting correction, the mean absolute error is limited to 6 nm or 0.03 eV for the 57 diarylethenes considered. To unravel the most important parameters for this photochromic class, several structural parameters are correlated to the UV/vis spectra. It turns out that the bond length alternation in the chromogenic unit allows a fast and accurate prediction of the color of these dyes. In addition, we compare our results to available electrochemical data.

Research paper thumbnail of Towards the understanding of the chromatic behaviour of triphenylmethane derivatives

Chemical Physics, 2007

The absorption spectra of a large panel of substituted arylcarbonium dyes have been simulated wit... more The absorption spectra of a large panel of substituted arylcarbonium dyes have been simulated with the PCM-TD-DFT theoretical scheme. For most compounds, there are at least two allowed excited-states showing a strong molar absorption coefficient in the UV/Vis region. Both involve a charge transfer from the para-NMe2 to the central carbonium. It turns out that B3LYP, combined with the 6-31G(d,p)

Research paper thumbnail of TD-DFT Investigation of the UV Spectra of Pyranone Derivatives

Journal of Physical Chemistry A, 2006

The UV absorption spectra of more than 80 substituted coumarins and chromones have been investiga... more The UV absorption spectra of more than 80 substituted coumarins and chromones have been investigated with the PCM-TD-DFT theoretical scheme using three hybrid functionals (O3LYP, B3LYP, and PBE0) and taking into account methanol or ethanol solvation effects. For most of the studied derivatives, there are at least two allowed excited states presenting a strong oscillator strength in the UV region. The first allowed excitation is associated to a HOMO-LUMO transition whereas the second corresponds to a transition from the HOMO-1 to the LUMO. Both involve a charge transfer from the benzenic cycle to the pyranone moiety. Statistically treating the PBE0 results allows a prediction of the lambda(max) with small standard deviations: in methanol, 6 nm (0.07 eV) for the first excitation (lambda(max)(1)) and 5 nm (0.08 eV) for the second one (lambda(max)(2)), whereas in ethanol 6 nm (0.08 eV) for (lambda(max)(1)) and 6 nm (0.13 eV) for (lambda(max)(2)).

Research paper thumbnail of The n → π* transition in nitroso compounds: A TD-DFT study

Chemical Physics Letters, 2006

The visible spectra of a series of various nitroso dyes have been evaluated by using time-depende... more The visible spectra of a series of various nitroso dyes have been evaluated by using time-dependent density functional theory approach and explicitly taking into account bulk solvent effects. Using the PBE0 functional with the 6-311++G(3d,3p) atomic basis set, the agreement between theoretical and experimental n→π* transition energies is excellent for all nitroso species. The mean absolute error is limited to

Research paper thumbnail of Ab initio calculations of the colour of closed-ring diarylethenes: TD-DFT estimates for molecular switches

Chemical Physics Letters, 2006

The visible absorption spectra of a series of diarylethene dyes have been evaluated by using a ti... more The visible absorption spectra of a series of diarylethene dyes have been evaluated by using a time-dependent density functional theory approach, explicitly taking into account bulk solvent effects. A complete basis set/functional methodological study has been performed. Using the PBE0 functional with the 6-311+G(2d,p) atomic basis set, we got a nice agreement between theoretical and experimental electronic transition energies for

Research paper thumbnail of Toward a Theoretical Quantitative Estimation of the λ m ax of Anthraquinones-Based Dyes

Journal of Chemical Theory and Computation, 2006

We have computed the absorption spectra of a large series of anthraquinone dyes by using the time... more We have computed the absorption spectra of a large series of anthraquinone dyes by using the time-dependent density functional theory (TD-DFT) for the excited-state calculations and the polarizable continuum model (PCM) for evaluating bulk solvent effects. On one hand, we compare the results obtained with the B3LYP and the PBE0 hybrid functionals, combined with different atomic basis sets. On the other hand, using multiple linear regression, we take advantage of the λmax predicted by these two functionals in order to reach the best agreement between theoretical estimates and experimental measurements. It turns out that 1. PBE0 provides more accurate results than B3LYP; in addition the average errors provided by the former are less basis set dependent. 2. Multiple linear regression provides excited state spectra in better agreement with experiment than any simple linear fit that could be performed. 3. Using our best fitting procedure, we obtained a mean absolute error of 6 nm for a set of 66 anthraquinones, with no deviations exceeding 25 nm. The related standard deviation, useful for predictions, is only 8 nm, i.e.,[Formula: see text] =[Formula: see text] ± 8 nm (or ±0.05 eV) for unknown anthraquinone compounds.

Research paper thumbnail of A TD-DFT study of the absorption spectra of fast dye salts

Chemical Physics Letters, 2005

The UV/visible spectra of a series of diazonium (N2+) fast dyes have been evaluated by using a ti... more The UV/visible spectra of a series of diazonium (N2+) fast dyes have been evaluated by using a time-dependent density functional theory approach explicitly taking into account bulk solvation effects. Using the PBE0 functional with the 6-311G(2d,2p) atomic basis set, the agreement between theory and experiment is excellent for these cationic species. The effects on the spectra of chemical substitution are

Research paper thumbnail of Extensive TD-DFT Benchmark: Singlet-Excited States of Organic Molecules

Journal of Chemical Theory and Computation, 2009

Extensive Time-Dependent Density Functional Theory (TD-DFT) calculations have been carried out in... more Extensive Time-Dependent Density Functional Theory (TD-DFT) calculations have been carried out in order to obtain a statistically meaningful analysis of the merits of a large number of functionals. To reach this goal, a very extended set of molecules (∼500 compounds, >700 excited states) covering a broad range of (bio)organic molecules and dyes have been investigated. Likewise, 29 functionals including LDA, GGA, meta-GGA, global hybrids, and longrange-corrected hybrids have been considered. Comparisons with both theoretical references and experimental measurements have been carried out. On average, the functionals providing the best match with reference data are, one the one hand, global hybrids containing between 22% and 25% of exact exchange (X3LYP, B98, PBE0, and mPW1PW91) and, on the other hand, a long-range-corrected hybrid with a less-rapidly increasing HF ratio, namely LC-ωPBE(20). Pure functionals tend to be less consistent, whereas functionals incorporating a larger fraction of exact exchange tend to underestimate significantly the transition energies. For most treated cases, the M05 and CAM-B3LYP schemes deliver fairly small deviations but do not outperform standard hybrids such as X3LYP or PBE0, at least within the vertical approximation. With the optimal functionals, one obtains mean absolute deviations smaller than 0.25 eV, though the errors significantly depend on the subset of molecules or states considered. As an illustration, PBE0 and LC-ωPBE(20) provide a mean absolute error of only 0.14 eV for the 228 states related to neutral organic dyes but are completely off target for cyanine-like derivatives. On the basis of comparisons with theoretical estimates, it also turned out that CC2 and TD-DFT errors are of the same order of magnitude, once the above-mentioned hybrids are selected.

Research paper thumbnail of Thioindigo Dyes:  Highly Accurate Visible Spectra with TD-DFT

Journal of The American Chemical Society, 2006

The structure and visible spectra of a large panel of thioindigo dyes and derivatives have been e... more The structure and visible spectra of a large panel of thioindigo dyes and derivatives have been evaluated using a TD-PBE0/6-311+G(2d,p)//PBE0/6-311G(d,p) approach explicitly taking bulk solvent effects into account by means of the polarizable continuum model. The influence of the solvent characteristics, the trans-cis isomerization, and the chemical substitution on the benzene rings have been investigated. In addition, hemi-thioindigo dyes, thiazine-indigo, chromophore-like molecules, and selenoindigo have been considered. Though the relative oscillator strengths of the two allowed visible transitions in the nonplanar cis isomers are not always correctly reproduced by theory, the agreement between theoretical and experimental results is far above expectations. For the 170 cases studied, we obtained a mean unsigned error on the predicted lambda(max) limited to 6.9 nm or 0.03 eV, with only 6 (4) cases for which the difference exceeds 20 nm (0.10 eV). These errors are 1 order of magnitude smaller than what has previously been reported for indigoids. A linear correlation between the central double bond length and the lambda(max) has been established, while the bond length and vibrational frequency of the carbonyl groups do not correlate with the thioindigo color. The higher excitation energies of the cis conformers, compared to the trans structures, result from a less stabilized LUMO in the former case. Indeed, for cis thioindigo, the two electron-rich (in the excited state) carbonyl units lie close to each other.

Research paper thumbnail of TD-DFT Performance for the Visible Absorption Spectra of Organic Dyes:  Conventional versus Long-Range Hybrids

Journal of Chemical Theory and Computation, 2008

... Denis Jacquemin,* † Eric A. Perpète, † Gustavo E. Scuseria, ‡ Ilaria Ciofini, § and Carlo Ada... more ... Denis Jacquemin,* † Eric A. Perpète, † Gustavo E. Scuseria, ‡ Ilaria Ciofini, § and Carlo Adamo* §. Laboratoire de Chimie Théorique Appliquée, Groupe de Chimie-Physique Théorique et Structurale, Facultés Universitaires ...

Research paper thumbnail of Ab initio determination of the vibrational and electronic first hyperpolarizabilities of reference compounds for non-linear optical (NLO) applications 3Methyl 4-nitropyridine 1-oxide (POM) and N-(4-nitrophenyl)-(L)-prolinol (NPP)

Journal of The Chemical Society, Faraday Transactions, 1998

The electronic and vibrational Ðrst hyperpolarizabilities of POM and NPP are determined at the HF... more The electronic and vibrational Ðrst hyperpolarizabilities of POM and NPP are determined at the HF/6-311G** level of approximation by using the coupled HartreeÈFock and double harmonic oscillator schemes, respectively. The geometrical parameters, charge distributions, Ðrst hyperpolarizabilities and vibrational normal modes and frequencies of POM and NPP are compared with available experimental and theoretical investigations. The vibrational Ðrst hyperpolarizability is analysed in terms of the most contributing vibrational normal modes. The ratio between the vibrational and electronic Ðrst hyperpolarizabilities is considered as a function of the chemical nature of the p-conjugated system, the NLO process and the response time.

Research paper thumbnail of Investigation of the complexation reaction between 2-diethylaminomethyl-4-methylphenol and ZnCl2. Reaction mechanism and solvent effects

Journal of Molecular Structure: THEOCHEM, 2006

ABSTRACT The reaction mechanism of the chemical reaction of 2-diethylaminomethyl-4-methylphenolat... more ABSTRACT The reaction mechanism of the chemical reaction of 2-diethylaminomethyl-4-methylphenolate with ZnCl2 is investigated by means of the PM3 semi-empirical method. We propose two different but competitive stepwise pathways going from the isolated reactants to the tetra-coordinated bidentate final complex, where the zinc atom is bonded both to the oxygen and to the nitrogen atom of the ligand. Each pathway proceeds via different monodentate intermediate complexes. This study shows that either the first chemical bond formed between ZnCl2 and 2-diethylaminomethyl-4-methylphenolate is the Zn–O bond or the Zn–N bond. The direct pathway going from the reactants to the final product through a concerted asynchronous mechanism is found to be unrealistic, since it involves a second order saddle point.Solvent effects are taken into account with the SCRF dielectric continuum model at the PM3 and (RHF/3-21G) levels of theory. This preliminary study shows that the complex formation is favored by the use of polar solvent.

Research paper thumbnail of Vibrational frequencies of H2O and CO2 from Car-Parrinello molecular dynamics

Journal of Molecular Structure: THEOCHEM, 1998

Using plane wave basis functions within the local density approximation, the Car-Parrinello molec... more Using plane wave basis functions within the local density approximation, the Car-Parrinello molecular dynamics scheme has been applied to evaluate the vibrational frequencies of the H2O and CO2 molecules. This dynamical approach using the plane wave basis set provides estimates of similar quality to standard density functional schemes using gaussian basis sets.

Research paper thumbnail of A TD-DFT investigation of the visible spectra of fluoro-anthraquinones

With ab initio computational chemistry techniques explicitly taking into account electron correla... more With ab initio computational chemistry techniques explicitly taking into account electron correlation and solvent effects, we investigate the chemical substitution impact on the l max of absorption, of 1,2,3,4-tetrafluoro-9,10-anthraquinone. Increasing the electron-donating strength of the auxochromic groups leads to bathochromic displacements. The largest bathochromic effect has been observed when four built-up hydrogen bonds interact with the C]O chromophores. For each substitution, the results are rationalized in terms of HOMO and LUMO energy levels, as well as in hydrogen bond effects on the charge separation and bond length in the chromophoric unit.

Research paper thumbnail of Simulation of the Properties of a Photochromic Triad

Journal of Physical Chemistry Letters, 2010

ABSTRACT

Research paper thumbnail of Ab Initio Investigation of the Electronic Properties of Coupled Dithienylethenes

Journal of Physical Chemistry Letters, 2010

The electronic structures and magnetism of the half-Heusler alloys XCrAl (X ¼ Fe, Co, Ni) and NiC... more The electronic structures and magnetism of the half-Heusler alloys XCrAl (X ¼ Fe, Co, Ni) and NiCrZ (Z ¼ Al, Ga, In) have been investigated to search for new candidate half-metallic materials. Here, we predict that NiCrAl, and NiCrGa and NiCrIn are possible halfmetals with an energy gap in the minority spin and a completely spin polarization at the Fermi level. The energy gap can be attributed to the covalent hybridization between the d states of the Ni and Cr atoms, which leads to the formation of bonding and antibonding peaks with a gap in between them. Their total magnetic moments are 1m B per unit cell; agree with the Slater-Pauling rule. The partial moment of Cr is largest in NiCrZ alloys and moments of Ni and Al are in antiferromagnetic alignment with Cr. Meanwhile, it is also found that FeCrAl is a normal ferromagnetic metal with a magnetic moment of 0.25m B per unit cell and CoCrAl is a semi-metal and non-magnetic. r

Research paper thumbnail of TD-DFT simulations of the electronic properties of star-shaped photochromes

Physical Chemistry Chemical Physics, 2010

We have investigated, with the help of time-dependent density functional theory, the UV/Vis absor... more We have investigated, with the help of time-dependent density functional theory, the UV/Vis absorption features of three diarylethenes coupled through a pi-electron rich moiety. For this star-shaped molecular architecture, the modifications of the electronic signatures induced by the ring-closure of one, two or three diarylethenes are carefully examined. The obtained theoretical results compare favorably with the available experimental data, and allow to reach conclusions helpful for the design of more efficient assemblies combining several molecular switches.

Research paper thumbnail of Doubly Closing or Not? Theoretical Analysis for Coupled Photochromes

Journal of Physical Chemistry C, 2010

ABSTRACT

Research paper thumbnail of A theoretical study of the perfluoro-diarylethenes electronic spectra

Journal of Photochemistry and Photobiology A-chemistry, 2008

Using a combination of the time-dependent density functional theory and the polarizable continuum... more Using a combination of the time-dependent density functional theory and the polarizable continuum model, we have investigated the visible spectra of 129 closed-ring perfluorocyclopentene diarylethenes, solvated in various environments (185 cases). The theoretical simulations are able to reproduce the major experimental trends, especially the auxochromic shifts though solvatochromic effects in protic media are not correctly modelled. A quantitative agreement, that

Research paper thumbnail of An ab initio study of the absorption spectra of indirubin, isoindigo, and related derivatives

The journal of physical chemistry. A, Jan 4, 2006

The UV/visible spectra of a series of indirubin, isoindigo, and other indigo/thioindigo related d... more The UV/visible spectra of a series of indirubin, isoindigo, and other indigo/thioindigo related dyes have been evaluated in various solvent environments by using the time-dependent density functional theory in conjunction with the polarizable continuum model. Even for molecules of the same family, significant differences in the excitation processes have been noted. Two hybrid functionals have been selected: B3LYP and PBE0. For a set of the 50 selected molecular cases, both functionals provide accurate lambda(max), with mean absolute deviations limited to 0.1 eV. Actually, isoindigo is the main challenging series, with systematically underestimated excitation energies, due to the different nature of the excitation process. In most cases, we found that PBE0 is more efficient in reproducing the experimental values than B3LYP for sulfur-containing dyes not featuring internal hydrogen bonds, the reverse assertion being also true. In addition, the spectra of a series of unknown dyes have ...

Research paper thumbnail of TD-DFT investigation of diarylethene dyes with cyclopentene, dihydrothiophene, and dihydropyrrole bridges

The journal of physical chemistry. A, Jan 28, 2007

We have investigated the visible spectra of closed-ring diarylethenes presenting cyclopentene, di... more We have investigated the visible spectra of closed-ring diarylethenes presenting cyclopentene, dihydrothiophene, and dihydropyrrole bridging structures. Our simulations have been performed with an ab initio time-dependent density functional theory approach that takes into account bulk environmental effects. The computed lambda(max) agree qualitatively with experiment, and once a simple statistical treatment is performed, a quantitative agreement is reached. Indeed, after linear fitting correction, the mean absolute error is limited to 6 nm or 0.03 eV for the 57 diarylethenes considered. To unravel the most important parameters for this photochromic class, several structural parameters are correlated to the UV/vis spectra. It turns out that the bond length alternation in the chromogenic unit allows a fast and accurate prediction of the color of these dyes. In addition, we compare our results to available electrochemical data.

Research paper thumbnail of Towards the understanding of the chromatic behaviour of triphenylmethane derivatives

Chemical Physics, 2007

The absorption spectra of a large panel of substituted arylcarbonium dyes have been simulated wit... more The absorption spectra of a large panel of substituted arylcarbonium dyes have been simulated with the PCM-TD-DFT theoretical scheme. For most compounds, there are at least two allowed excited-states showing a strong molar absorption coefficient in the UV/Vis region. Both involve a charge transfer from the para-NMe2 to the central carbonium. It turns out that B3LYP, combined with the 6-31G(d,p)

Research paper thumbnail of TD-DFT Investigation of the UV Spectra of Pyranone Derivatives

Journal of Physical Chemistry A, 2006

The UV absorption spectra of more than 80 substituted coumarins and chromones have been investiga... more The UV absorption spectra of more than 80 substituted coumarins and chromones have been investigated with the PCM-TD-DFT theoretical scheme using three hybrid functionals (O3LYP, B3LYP, and PBE0) and taking into account methanol or ethanol solvation effects. For most of the studied derivatives, there are at least two allowed excited states presenting a strong oscillator strength in the UV region. The first allowed excitation is associated to a HOMO-LUMO transition whereas the second corresponds to a transition from the HOMO-1 to the LUMO. Both involve a charge transfer from the benzenic cycle to the pyranone moiety. Statistically treating the PBE0 results allows a prediction of the lambda(max) with small standard deviations: in methanol, 6 nm (0.07 eV) for the first excitation (lambda(max)(1)) and 5 nm (0.08 eV) for the second one (lambda(max)(2)), whereas in ethanol 6 nm (0.08 eV) for (lambda(max)(1)) and 6 nm (0.13 eV) for (lambda(max)(2)).

Research paper thumbnail of The n → π* transition in nitroso compounds: A TD-DFT study

Chemical Physics Letters, 2006

The visible spectra of a series of various nitroso dyes have been evaluated by using time-depende... more The visible spectra of a series of various nitroso dyes have been evaluated by using time-dependent density functional theory approach and explicitly taking into account bulk solvent effects. Using the PBE0 functional with the 6-311++G(3d,3p) atomic basis set, the agreement between theoretical and experimental n→π* transition energies is excellent for all nitroso species. The mean absolute error is limited to

Research paper thumbnail of Ab initio calculations of the colour of closed-ring diarylethenes: TD-DFT estimates for molecular switches

Chemical Physics Letters, 2006

The visible absorption spectra of a series of diarylethene dyes have been evaluated by using a ti... more The visible absorption spectra of a series of diarylethene dyes have been evaluated by using a time-dependent density functional theory approach, explicitly taking into account bulk solvent effects. A complete basis set/functional methodological study has been performed. Using the PBE0 functional with the 6-311+G(2d,p) atomic basis set, we got a nice agreement between theoretical and experimental electronic transition energies for

Research paper thumbnail of Toward a Theoretical Quantitative Estimation of the λ m ax of Anthraquinones-Based Dyes

Journal of Chemical Theory and Computation, 2006

We have computed the absorption spectra of a large series of anthraquinone dyes by using the time... more We have computed the absorption spectra of a large series of anthraquinone dyes by using the time-dependent density functional theory (TD-DFT) for the excited-state calculations and the polarizable continuum model (PCM) for evaluating bulk solvent effects. On one hand, we compare the results obtained with the B3LYP and the PBE0 hybrid functionals, combined with different atomic basis sets. On the other hand, using multiple linear regression, we take advantage of the λmax predicted by these two functionals in order to reach the best agreement between theoretical estimates and experimental measurements. It turns out that 1. PBE0 provides more accurate results than B3LYP; in addition the average errors provided by the former are less basis set dependent. 2. Multiple linear regression provides excited state spectra in better agreement with experiment than any simple linear fit that could be performed. 3. Using our best fitting procedure, we obtained a mean absolute error of 6 nm for a set of 66 anthraquinones, with no deviations exceeding 25 nm. The related standard deviation, useful for predictions, is only 8 nm, i.e.,[Formula: see text] =[Formula: see text] ± 8 nm (or ±0.05 eV) for unknown anthraquinone compounds.

Research paper thumbnail of A TD-DFT study of the absorption spectra of fast dye salts

Chemical Physics Letters, 2005

The UV/visible spectra of a series of diazonium (N2+) fast dyes have been evaluated by using a ti... more The UV/visible spectra of a series of diazonium (N2+) fast dyes have been evaluated by using a time-dependent density functional theory approach explicitly taking into account bulk solvation effects. Using the PBE0 functional with the 6-311G(2d,2p) atomic basis set, the agreement between theory and experiment is excellent for these cationic species. The effects on the spectra of chemical substitution are

Research paper thumbnail of Extensive TD-DFT Benchmark: Singlet-Excited States of Organic Molecules

Journal of Chemical Theory and Computation, 2009

Extensive Time-Dependent Density Functional Theory (TD-DFT) calculations have been carried out in... more Extensive Time-Dependent Density Functional Theory (TD-DFT) calculations have been carried out in order to obtain a statistically meaningful analysis of the merits of a large number of functionals. To reach this goal, a very extended set of molecules (∼500 compounds, >700 excited states) covering a broad range of (bio)organic molecules and dyes have been investigated. Likewise, 29 functionals including LDA, GGA, meta-GGA, global hybrids, and longrange-corrected hybrids have been considered. Comparisons with both theoretical references and experimental measurements have been carried out. On average, the functionals providing the best match with reference data are, one the one hand, global hybrids containing between 22% and 25% of exact exchange (X3LYP, B98, PBE0, and mPW1PW91) and, on the other hand, a long-range-corrected hybrid with a less-rapidly increasing HF ratio, namely LC-ωPBE(20). Pure functionals tend to be less consistent, whereas functionals incorporating a larger fraction of exact exchange tend to underestimate significantly the transition energies. For most treated cases, the M05 and CAM-B3LYP schemes deliver fairly small deviations but do not outperform standard hybrids such as X3LYP or PBE0, at least within the vertical approximation. With the optimal functionals, one obtains mean absolute deviations smaller than 0.25 eV, though the errors significantly depend on the subset of molecules or states considered. As an illustration, PBE0 and LC-ωPBE(20) provide a mean absolute error of only 0.14 eV for the 228 states related to neutral organic dyes but are completely off target for cyanine-like derivatives. On the basis of comparisons with theoretical estimates, it also turned out that CC2 and TD-DFT errors are of the same order of magnitude, once the above-mentioned hybrids are selected.

Research paper thumbnail of Thioindigo Dyes:  Highly Accurate Visible Spectra with TD-DFT

Journal of The American Chemical Society, 2006

The structure and visible spectra of a large panel of thioindigo dyes and derivatives have been e... more The structure and visible spectra of a large panel of thioindigo dyes and derivatives have been evaluated using a TD-PBE0/6-311+G(2d,p)//PBE0/6-311G(d,p) approach explicitly taking bulk solvent effects into account by means of the polarizable continuum model. The influence of the solvent characteristics, the trans-cis isomerization, and the chemical substitution on the benzene rings have been investigated. In addition, hemi-thioindigo dyes, thiazine-indigo, chromophore-like molecules, and selenoindigo have been considered. Though the relative oscillator strengths of the two allowed visible transitions in the nonplanar cis isomers are not always correctly reproduced by theory, the agreement between theoretical and experimental results is far above expectations. For the 170 cases studied, we obtained a mean unsigned error on the predicted lambda(max) limited to 6.9 nm or 0.03 eV, with only 6 (4) cases for which the difference exceeds 20 nm (0.10 eV). These errors are 1 order of magnitude smaller than what has previously been reported for indigoids. A linear correlation between the central double bond length and the lambda(max) has been established, while the bond length and vibrational frequency of the carbonyl groups do not correlate with the thioindigo color. The higher excitation energies of the cis conformers, compared to the trans structures, result from a less stabilized LUMO in the former case. Indeed, for cis thioindigo, the two electron-rich (in the excited state) carbonyl units lie close to each other.

Research paper thumbnail of TD-DFT Performance for the Visible Absorption Spectra of Organic Dyes:  Conventional versus Long-Range Hybrids

Journal of Chemical Theory and Computation, 2008

... Denis Jacquemin,* † Eric A. Perpète, † Gustavo E. Scuseria, ‡ Ilaria Ciofini, § and Carlo Ada... more ... Denis Jacquemin,* † Eric A. Perpète, † Gustavo E. Scuseria, ‡ Ilaria Ciofini, § and Carlo Adamo* §. Laboratoire de Chimie Théorique Appliquée, Groupe de Chimie-Physique Théorique et Structurale, Facultés Universitaires ...

Research paper thumbnail of Ab initio determination of the vibrational and electronic first hyperpolarizabilities of reference compounds for non-linear optical (NLO) applications 3Methyl 4-nitropyridine 1-oxide (POM) and N-(4-nitrophenyl)-(L)-prolinol (NPP)

Journal of The Chemical Society, Faraday Transactions, 1998

The electronic and vibrational Ðrst hyperpolarizabilities of POM and NPP are determined at the HF... more The electronic and vibrational Ðrst hyperpolarizabilities of POM and NPP are determined at the HF/6-311G** level of approximation by using the coupled HartreeÈFock and double harmonic oscillator schemes, respectively. The geometrical parameters, charge distributions, Ðrst hyperpolarizabilities and vibrational normal modes and frequencies of POM and NPP are compared with available experimental and theoretical investigations. The vibrational Ðrst hyperpolarizability is analysed in terms of the most contributing vibrational normal modes. The ratio between the vibrational and electronic Ðrst hyperpolarizabilities is considered as a function of the chemical nature of the p-conjugated system, the NLO process and the response time.