Improved density functional description of the electrochemistry and structure-property descriptors of substituted flavins.
The energetics of electrochemical changes have been investigated for several substituted flavins with the M06-L density functional. The reduction potentials for one- and two-electron reductions of these molecules have been determined and the results are consistent with experimental findings with a mean unsigned error of only 42 mV. It is especially noteworthy that the M06-L density functional makes a significant difference in the computed free energy of the first reduction of lumiflavin, which produces a neutral semiquinone. We also investigate the effects of flavin ring substituents on the geometries, charge distributions, reduction potentials, pK(a)'s, ionization potentials, electron affinities, hardnesses, softnesses, electrophilic powers, and nucleophilicities.
Department of Chemistry, University of Wisconsin-Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin 54702, USA.
Michael A
MA
North
Sudeep
S
Bhattacharyya
Donald G
DG
Truhlar
D004563:Electrochemistry; D004583:Electrons; D005415:Flavins / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011522:Protons; D011809:Quinones / Q000737:chemistry; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D005415:Flavins; D011522:Protons; D011809:Quinones; C001922:lumiflavin