Stereoelectronic, Vibrational, and Environmental Contributions to Polarizabilities of Large Molecular Systems: A Feasible Anharmonic Protocol

Egidi, Franco; Giovannini, Tommaso; Piccardo, Matteo; Bloino, Julien; Cappelli, Chiara; Barone, Vincenzo

doi:10.1021/ct500210z

Cited by 44 publications

(52 citation statements)

References 61 publications

(113 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The excellent match between the simulated and the observed spectra allows us to assign the vibrational normal modes contributing to the phosphorescence phenomenon of 2 . This was carried out using the computed shift‐vectors (i. e., using the gradient of the final state projected onto the normal modes of the initial state) …”

Section: Resultsmentioning

confidence: 99%

Insights into the Optical Properties of Triarylboranes with Strongly Electron‐Accepting Bis(fluoromesityl)boryl Groups: when Theory Meets Experiment

et al. 2019

View full text Add to dashboard Cite

The photophysical properties (absorption, fluorescence and phosphorescence) of a series of triarylboranes of the form 4‐D−C6H4−B(Ar)2 (D=tBu or NPh2; Ar=mesityl (Mes) or 2,4,6‐tris(trifluoromethylphenyl (Fmes)) were analyzed theoretically using state‐of‐the‐art DFT and TD‐DFT methods. Simulated emission spectra and computed decay rate constants are in very good agreement with the experimental data. Unrestricted electronic computations including vibronic contributions explain the unusual optical behavior of 4‐tBu−C6H4−B(Fmes)2 2, which shows both fluorescence and phosphorescence at nearly identical energies (at 77 K in a frozen glass). Analysis of the main normal modes responsible for the phosphorescence vibrational fine structure indicates that the bulky tert‐butyl group tethered to the phenyl ring is strongly involved. Interestingly, in THF solvent, the computed energies of the singlet and triplet excited states are very similar for compound 2 only, which may explain why 2 shows phosphorescence in contrast to the other members of the series.

show abstract

Section: Resultsmentioning

confidence: 99%

Insights into the Optical Properties of Triarylboranes with Strongly Electron‐Accepting Bis(fluoromesityl)boryl Groups: when Theory Meets Experiment

et al. 2019

View full text Add to dashboard Cite

show abstract

“…In these cases, the relative magnitude of them could only be determined by quantum chemical calculations. [8][9][10][11] It is also noted that the effects of higher-order terms were also discussed in recent studies. 11 For non-resonant Raman scattering processes, we focus on the zero-frequency limit, i.e., the ω is neglected.…”

Section: Introductionmentioning

confidence: 93%

Significant Contributions of the Albrecht’s A Term to Nonresonant Raman Scattering Processes

Gong

Tian

Duan

et al. 2015

J. Chem. Theory Comput.

View full text Add to dashboard Cite

The Raman intensity can be well described by the famous Albrecht's Raman theory that consists of A and B terms. It is well-known that the contribution from Albrecht's A term can be neglected without any loss of accuracy for far-off resonant Raman scattering processes. However, as demonstrated in this study, we have found that this widely accepted long-standing assumption fails drastically for totally symmetric vibration modes of molecules in general off-resonant Raman scattering. Perturbed first-principles calculations for water molecule show that strong constructive interference between the A and B terms occurs for the Raman intensity of the symmetric O-H stretching mode, which can account for ∼40% of the total intensity. Meanwhile, a minor destructive interference is found for the angle bending mode. The state-to-state mapping between Albrecht's theory and perturbation theory allows us to verify the accuracy of the widely employed perturbation method for the dynamic/resonant Raman intensities. The model calculations rationalized from water molecule with the bending mode show that the perturbation method is a good approximation only when the absolute energy difference between the first excited state and the incident light is more than five times greater than the vibrational energy in the ground state.

show abstract

“…For the resonant (or pre‐resonant) regime, a different formalism needs to be followed, which will not be presented here. Discussions on the vibronic calculations of resonance Raman spectra can be found in references , and , and references therein for instance. Both quantities considered here (

bold-italicμ

and

bold-italicα

) are functions of the normal coordinates, so there is no need for a general formulation such as the one adopted in references and 52.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Aiming at an accurate prediction of vibrational and electronic spectra for medium‐to‐large molecules: An overview

Bloino

Baiardi

Biczysko

2016

Int J of Quantum Chemistry

Self Cite

181

196

View full text Add to dashboard Cite

In this tutorial review, we present some effective methodologies available for the simulation of vibrational and vibrationally resolved electronic spectra of medium-to-large molecules. They have been integrated into a unified platform and extended to support a wide range of spectroscopies.The resulting tool is particularly useful in assisting the extensive characterization of molecules, often achieved by combining multiple types of measurements. A correct assessment of the reliability of theoretical calculations is a necessary prelude to the interpretation of their results. For this reason, the key concepts of the underlying theories will be first presented and then illustrated through the study of thiophene and its smallest oligomer, bithiophene. While doing so, a complete computational protocol will be detailed, with emphasis on the strengths and potential shortcomings of the models employed here. Guidelines are also provided for performing similar studies on different molecular systems, with comments on the more common pitfalls and ways to overcome them. Finally, extensions to other cases, like chiral spectroscopies or mixtures, are also discussed. K E Y W O R D Sanharmonic vibrational spectroscopy, computational spectroscopy, large amplitude motion, medium-to-large molecules, vibronic spectroscopy | I N T R O D U C T I O NMolecular properties are commonly probed with a wide panel of spectroscopies, which can be combined to offer a unique picture, reflection of the property, its environment, and the experimental conditions. [1][2][3][4][5][6][7][8] The wealth of information contained in the recorded spectrum or spectra can become complex to analyze in a purely phenomenological way and theoretical models can provide a valuable aid in understanding the origin of the features observed in the band-shapes. [9][10][11] As a matter of fact, the predictive and interpretative power of computational spectroscopy has been clearly demonstrated already for small molecular systems in the gas phase, by comparison with the most sophisticated experimental techniques. [1,[12][13][14] However, depending on the target system and the required accuracy, the theoretical spectroscopic models can vary greatly in complexity. The situation is even more challenging when considering their actual implementation, often done in ad hoc, standalone programs, whose levels of completion, versatility and ease of use may be very different. As a result, getting an extensive picture of the experimental spectra can become a challenge as it may require multiple packages with their own usage and peculiarities.Hence, to facilitate the simulation and interpretation of multiple spectra, several conditions need to be met. A first challenge is to provide a simple interface, lowering the barrier to the broad adoption of state-of-the-art methods able to produce accurate data for the problems at hand. [11,[15][16][17] This can be achieved by automatizing most aspects of the calculations. Due to the inherent complexity of some theoretical models, such ...

show abstract

Stereoelectronic, Vibrational, and Environmental Contributions to Polarizabilities of Large Molecular Systems: A Feasible Anharmonic Protocol

Cited by 44 publications

References 61 publications

Insights into the Optical Properties of Triarylboranes with Strongly Electron‐Accepting Bis(fluoromesityl)boryl Groups: when Theory Meets Experiment

Insights into the Optical Properties of Triarylboranes with Strongly Electron‐Accepting Bis(fluoromesityl)boryl Groups: when Theory Meets Experiment

Significant Contributions of the Albrecht’s A Term to Nonresonant Raman Scattering Processes

Aiming at an accurate prediction of vibrational and electronic spectra for medium‐to‐large molecules: An overview

Contact Info

Product

Resources

About