Semiempirical and Ab Initio Studies of the Structure and Spectroscopy of the Azo Dye Direct Blue 1: Comparison with Experiment
| Autor: | Laurence C. Abbott, Stephen Norman Batchelor, John Oakes, John R. Lindsay Smith, John N. Moore |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Biphenyl
Infrared Chemistry Ab initio Infrared spectroscopy symbols.namesake chemistry.chemical_compound Computational chemistry Excited state Physics::Atomic and Molecular Clusters symbols Physical chemistry Density functional theory Physics::Atomic Physics Physics::Chemical Physics Physical and Theoretical Chemistry Raman spectroscopy Spectroscopy |
| Zdroj: | The Journal of Physical Chemistry A. 108:10208-10218 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp047234f |
| Popis: | The structure and spectroscopy of the bis-azo dye Direct Blue 1 have been studied using semiempirical, Hartree−Fock, and density functional theory (DFT) calculations, and the results have been compared with those from experiment. The calculated dye structure comprises two essentially identical near-planar halves with a twist about the central biphenyl bond; the structures produced by the semiempirical AM1 method and the ab initio Hartree−Fock and DFT methods were found to be similar to each other. Excited-state calculations describe the transition to the lowest excited state of Direct Blue 1 as a charge transfer from the central biphenyl group onto both naphthyl rings, along with charge redistribution within the region of the hydrazone groups. Infrared and Raman spectra calculated by ab initio methods match the experimental spectra well; by contrast, IR spectra were modeled poorly by the semiempirical AM1 method. NMR resonances calculated with the DFT methods give good correlation with the experimental NM... |
| Databáze: | OpenAIRE |
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