Comparison of Spin Density Calculation Methods for Various AlkylSubstituted 9,10-Anthraquinone Anion Radicals in the Solution Phase

Eloranta, Jussi; Vatanen, Virpi; Grönroos, Antti; Vuolle, Mikko; Mäkelä, Reijo; Heikkilä, Hilkka

doi:10.1002/(sici)1097-458x(199611)34:11<898::aid-omr985>3.3.co;2-i

Cited by 4 publications

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“…In general, the nitrogen hcc seems to be considerably larger in the case of para substitution compared with monosubstituted orˇ-disubstituted aminoanthraquinone radical anions. 13 -15 On comparing the results from our earlier work 13 where some aminoanthraquinone radical anions were generated chemically in different solvent systems (see Table 1), the hcc of nitrogen is seen to be larger in protic solvents. The solvent nature and the structure of the radical anion can explain these differences.…”

Section: Discussionmentioning

confidence: 98%

“…The high barrier is partly caused by the hydrogen bonding between the amino proton and the quinone oxygen. 13 Since the temperature change affecting to the linewidth broadening was not detected, this would suggest that the line broadening for 15DAAQ is due to cis-trans isomerism (Scheme 2). The cis-trans isomerism may occur when the quinoid oxygen forces the amino proton to point up or down with respect to the quinone ring plane.…”

Section: Discussionmentioning

confidence: 99%

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EPR and MO calculation studies on α-aminoanthraquinone anion radicals in aprotic solvents

1999

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The EPR spectra of electrolytically produced anion radicals of 1,4‐diamino‐9,10‐anthraquinone, 1,4‐bis‐(methylamino)‐9,10‐anthraquinone, 1‐amino‐4‐hydroxy‐9,10‐anthraquinone, 1,5‐diamino‐9,10‐anthraquinone and 1,8‐diamino‐4,5‐dihydroxy‐9,10‐anthraquinone were measured in N,N‐dimethylamine (DMF) and dimethylsulfoxide (DMSO). The isotropic hyperfine coupling constants (hcc) are assigned according to dihydroxy‐substituted anthraquinones and molecular orbital (MO) calculations made in this study. The results are compared with the radical anions of 1,4‐diamino‐ and 1,5‐diamino‐9,10‐anthraquinone made in protic solvents by chemical reduction. A tentative assignment of the hcc is made for 1‐amino‐4‐hydroxy‐9,10‐anthraquinone by MO calculations. The result show that the self‐consistent isodensity polarised continuum model (SCI‐PCM) gives hcc constants with good accuracy compared to the experimental hcc values. Copyright © 1999 John Wiley & Sons, Ltd.

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

EPR and MO calculation studies on α-aminoanthraquinone anion radicals in aprotic solvents

1999

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“…Apart from a constant offset, the experimental acetone, DMF and DMSO results follow the trend predicted by the DFT/SCIPCM calculations. For quinones, the performance 0.0630 0.0628 0.0627 NQ IHC (5,8) 0.0279 0.0298 0.0303 AQ line width 0.013 0.008 0.006 AQ IHC (2,3,6,7) 0.0979 0.0980 0.0978 AQ IHC (1,4,5,8) 0.0291 0.0292 0.0302 of the theoretical dielectric solvent model depends essentially on its ability to model the solvent cavity in the vicinity of the quinone oxygens, which have large negative partial charges q ¾ 0.6e . For small values of the dielectric constant, changes in IHCs are pronounced but the experimental difficulty is also greater in this region.…”

Section: Resultsmentioning

confidence: 99%

“…5 However, it often produced completely incorrect results, including IHCs for quinones, and therefore it could not be considered a reliable method. 6 Ab initio methods such as unrestricted Hartree-Fock typically produced results in even worse agreement with the experiments than INDO. Since then it has been recognized that accurate treatment of Ł Correspondence to: J. Eloranta, Department of Chemistry, University of Jyväskylä, PO Box 35, FIN-40351, Jyväskylä, Finland.…”

Section: Introductionmentioning

confidence: 98%

“…In recent years density functional theory (DFT)-based methods have been shown to account for electron correlation to a sufficient extent and provide computational scaling similar to the Hartree-Fock method. Early calculations generated promising results using this approach 6 and since then more refined reports have appeared. 8 As the IHCs in quinone radicals tend to be closely spaced, it was important to consider contributions arising from the dielectric response of the solvent, possible counter-ions and rotational averaging.…”

Section: Introductionmentioning

confidence: 99%

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Effects of static and dynamic perturbations on isotropic hyperfine coupling constants in some quinone radicals

Fiedler

Eloranta

2004

Magnetic Reson in Chemistry

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The effects of solvent dielectric response on the isotropic hyperfine coupling constants of the 1,4-benzoquinone, 1,4-naphthoquinone and 9,10-anthraquinone anions and 1,4-naphthalenediol cation radicals were studied by electron spin resonance (ESR) spectroscopy and by the theoretical density functional method within the polarizable continuum model. Experimental results demonstrate that the isotropic hyperfine coupling constants can be obtained with high accuracy and that the effects of solvent impurities can be minimized by careful sample preparation. The results obtained correlate well with theoretical predictions from density functional theory calculations. For 1,4-naphthalenediol both the solvent dielectric response as well as rotational averaging of the hydroxy groups were calculated. The overall results highlight the importance of static and dynamic perturbations to the couplings and aid in the assignation process of the couplings to specific magnetic nuclei.

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A Comparison of the Properties of Various Fused-Ring Quinones and Their Radical Anions Using Hartree−Fock and Hybrid Hartree−Fock/Density Functional Methods

Grafton

Wheeler

1997

J. Phys. Chem. A

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The hybrid Hartree−Fock/density functional B3LYP has been used to predict a variety of properties of 1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethyl-1,4-naphthoquinone, and 9,10-anthraquinone, as well as their radical anions. Geometries and spin properties show good agreement with experiment. The calculated adiabatic electron affinities show excellent agreement with previously determined experimental values, where available. An electron affinity of 1.63 eV is predicted for 2,3-dimethyl-1,4-naphthoquinone. A complete analysis of the vibrational spectra of each neutral molecule is provided and compared with available experimental and previous theoretical results. In each case, the CO antisymmetric stretching vibration is found to be slightly higher in frequency than the CO symmetric stretch. The first full analysis of the vibrational spectra of each of the radical anions is presented, and a comparison is made with the spectra of the neutral molecules. It is found that B3LYP/6-31G(d) theory consistently overestimates vibrational frequencies by 4−5%, in agreement with previous tests, but also does an excellent job of predicting the correct relative ordering of vibrational modes. Unrestricted Hartree−Fock geometries and frequencies are also provided for comparison.

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Comparison of Spin Density Calculation Methods for Various AlkylSubstituted 9,10-Anthraquinone Anion Radicals in the Solution Phase

Cited by 4 publications

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EPR and MO calculation studies on α-aminoanthraquinone anion radicals in aprotic solvents

EPR and MO calculation studies on α-aminoanthraquinone anion radicals in aprotic solvents

Effects of static and dynamic perturbations on isotropic hyperfine coupling constants in some quinone radicals

A Comparison of the Properties of Various Fused-Ring Quinones and Their Radical Anions Using Hartree−Fock and Hybrid Hartree−Fock/Density Functional Methods

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