Repozytorium

Integrated computational approaches for spectroscopic studies of molecular systems in the gas phase and in solution: pyrimidine as a test case

Autorzy

Małgorzata Biczysko

Julien Bloino

Giuseppe Brancato

Ivo Cacelli

Chiara Cappelli

Alessandro Ferretti

Alessandro Lami

Susanna Monti

Alfonso Pedone

Giacomo Prampolini

Cristina Puzzarini

Fabrizio Santoro

Fabio Trani

Giovanni Villani

Rok wydania

2012

Czasopismo

Theoretical Chemistry Accounts

Numer woluminu

131

Strony

1201/1-1201/19

DOI

10.1007/s00214-012-1201-3

Kolekcja

Naukowa

Język

Angielski

Typ publikacji

Artykuł

Streszczenie

An integrated computational approach built on quantum mechanical (QM) methods, purposely tailored inter- and intra-molecular force fields and continuum sol- vent models combined with time-independent and time-dependent schemes to account for nuclear motion effects is applied to the spectroscopic investigation of pyrimidine in the gas phase as well as in aqueous and CCl4 solutions. Accurate post-Hartree–Fock methodologies are employed to compute molecular structure, harmonic vibrational fre-quencies, energies and oscillator strengths for electronic transitions in order to validate the accuracy of approaches rooted into density functional theory with emphasis also on hybrid QM/QM0' models. Within the time-independent approaches, IR spectra are computed including anharmo-nicities through perturbative corrections while UV–vis line-shapes are simulated accounting for the vibrational structure; in both cases, the environmental effects are described by continuum models. The effects of confor-mational flexibility, including solvent dynamics, are described through time-dependent models based on pur-posely DFT-tailored force fields applied to molecular dynamics simulations and on QM computations of spec-troscopic properties. Such procedures are exploited to simulate IR and UV–vis spectra of pyrimidine in the gas phase and in solutions, leading in all cases to good agreement with experimental observations and allowing to dissect different effects underlying spectral phenomena.

Słowa kluczowe

Computational spectroscopy, Integrated approaches, QM/MM/PCM, DFT, Post-Hartree–Fock, CCSD(T), Composite schemes, Hybrid models, Molecular dynamics, Force fields, Time-independent approaches, Time-dependent approaches, Solvent effects, Vertical excitation energies, Electronic spectra, Spectra line-shape, Vibronic transitions, UV–vis, Resonance Raman, Vibrational spectra, IR intensities, Anharmonicity

Adres publiczny

http://dx.doi.org/10.1007/s00214-012-1201-3

Strona internetowa wydawcy

http://link.springer.com

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