Prediction of the reduction potential of tris(2,2′‐bipyridinyl)iron(III/II) derivatives

The reduction potentials of a tris(2,2′‐bipyridinyl)iron (III/II) and iron(III/II) couples complexed with 2,2′‐bipyridinyl derivatives in acetonitrile are predicted using density functional theory. The calculation protocol proposed by Kim et al. (Kim, J. Park, Y. S. Lee, J. Comput. Chem. 2013, 34, 2233) showing reliable performance for the reduction potential is used. The four kinds of the functional groups, a methoxy group, a methyl group, a chlorine atom, and a cyanide group, are substituted at the ligands to examine the electronic effect on the reduction potential. Electron donating/withdrawing effect is analyzed by comparing the reduction potential having different substituents at the same position. The influence of the geometrical strain on the reduction potential is investigated. The good correlation between the experimental results and the calculated results is obtained. Not only the general trend, but also the detailed phenomena are correctly reproduced. The maximum deviation from the experimental value is 0.083 V for the methyl substitution at the position 4. The mean absolute error for the seven couples is 0.047 V. The difference of the reduction potential between the chlorine atom substituted at the positions 4 and 5, 0.1 V, is well described. The difference between the CN and the Cl substitution of 0.318 and 0.228 V for the position 4 and 5 is correctly obtained as 0.325 and 0.213 V, respectively. The simple linear relation between the lowest unoccupied molecular orbital (LUMO) energy of the Fe(III) complexes in solution and the calculated reduction potentials is obtained with the R2 of 0.977. © 2014 Wiley Periodicals, Inc.

[1]  L. Wilson,et al.  Substituent effects on the spin equilibrium observed with hexadentate ligands on iron(II) , 1975 .

[2]  S. Trasatti.  The absolute electrode potential: an explanatory note (Recommendations 1986) , 1986 .

[3]  H. Callot,et al.  Effects of electron-withdrawing substituents on the electrochemical oxidation of porphyrins , 2002 .

[4]  M. Solà,et al.  Spin-state-corrected Gaussian-type orbital basis sets. , 2010, The journal of physical chemistry. A.

[5]  High energy lithium batteries by molecular wiring and targeting approaches , 2007 .

[6]  Ernst-Walter Knapp,et al.  Accurate redox potentials of mononuclear iron, manganese, and nickel model complexes* , 2009, J. Comput. Chem..

[7]  Amy L. Speelman,et al.  Efficient computational methods for accurately predicting reduction potentials of organic molecules. , 2008, The journal of physical chemistry. A.

[8]  Seung-Hyeon Moon,et al.  A review of current developments in non-aqueous redox flow batteries: characterization of their membranes for design perspective , 2013 .

[9]  Jerzy Leszczynski,et al.  Toward robust computational electrochemical predicting the environmental fate of organic pollutants , 2011, J. Comput. Chem..

[10]  L. E. Roy,et al.  Calculation of one-electron redox potentials revisited. Is it possible to calculate accurate potentials with density functional methods? , 2009, The journal of physical chemistry. A.

[11]  Jacopo Tomasi,et al.  A new integral equation formalism for the polarizable continuum model: Theoretical background and applications to isotropic and anisotropic dielectrics , 1997 .

[12]  Toru Matsui,et al.  Consistent scheme for computing standard hydrogen electrode and redox potentials , 2013, J. Comput. Chem..

[13]  Toomas Tamm,et al.  Density-Functional Theory Calculations of Aqueous Redox Potentials of Fourth-Period Transition Metals , 2003 .

[14]  Hyungjun Kim,et al.  A protocol to evaluate one electron redox potential for iron complexes , 2013, J. Comput. Chem..

[15]  A. B. P. Lever,et al.  Electrochemical parametrization of metal complex redox potentials, using the ruthenium(III)/ruthenium(II) couple to generate a ligand electrochemical series , 1990 .

[16]  M. H. Chakrabarti,et al.  Evaluation of electrolytes for redox flow battery applications , 2007 .

[17]  J. Beattie,et al.  Partial molal volumes of spin-equilibrium metal complexes , 1986 .

[18]  Jacopo Tomasi,et al.  Remarks on the use of the apparent surface charges (ASC) methods in solvation problems: Iterative versus matrix‐inversion procedures and the renormalization of the apparent charges , 1995, J. Comput. Chem..

[19]  Min‐Sik Park,et al.  Development of metal-based electrodes for non-aqueous redox flow batteries , 2011 .

[20]  Hisayoshi Kobayashi,et al.  DFT Method Estimation of Standard Redox Potential of Metal Ions and Metal Complexes. , 2007, Journal of chemical theory and computation.

[21]  C. Lin,et al.  Benchmark Calculations of Absolute Reduction Potential of Ferricinium/Ferrocene Couple in Nonaqueous Solutions. , 2010, Journal of chemical theory and computation.

[22]  G. Soloveichik,et al.  Reduction of Systematic Uncertainty in DFT Redox Potentials of Transition-Metal Complexes , 2012 .

[23]  Marcel Swart,et al.  Validation of Exchange-Correlation Functionals for Spin States of Iron Complexes , 2004 .

[24]  S. Zakeeruddin,et al.  Towards mediator design: Characterization of tris-(4,4′-substituted-2,2′-bipyridine) complexes of iron(II), ruthenium(II) and osmium(II) as mediators for glucose oxidase of Aspergillus niger and other redox proteins , 1992 .

[25]  R. Friesner,et al.  Computing Redox Potentials in Solution: Density Functional Theory as A Tool for Rational Design of Redox Agents , 2002 .

[26]  Corrine F. Elliott,et al.  Controlling Oxidation Potentials in Redox Shuttle Candidates for Lithium-Ion Batteries , 2014 .

[27]  Jacopo Tomasi,et al.  Molecular Interactions in Solution: An Overview of Methods Based on Continuous Distributions of the Solvent , 1994 .

[28]  F. Würthner,et al.  Tuning the Redox Properties of Photochromic Diarylethenes by Introducing Electron-Withdrawing Substituents , 2013 .