Theoretical Exploration of 2,2’-Bipyridines as Electro-Active Compounds in Flow Batteries

Abstract

Molecular information in SMILES code was used as input in Open Babel 2.4.0 \cite{O'Boyle2011} to find the minimum energy conformer using the MMFF94 force field. The generated geometries provided the cartesian coordinates that were used to generate a Gaussian input file. In some cases, it was necessary to apply a preliminary minimization using pseudopotentials (PM7) before performing the actual DFT calculation. Molecular energies of the 156 2,2'-bipirydines were obtained using the Gaussian 16 suite at DFT, with B3LYP hybrid functional and 6-31G(d) basis. Analysis of vibrational frequencies was performed to verify the existence of an energy minimum. All geometries were optimized using both the polarizable continuum model (PCM) \cite{Miertus1981,Scalmani2010} and the solvation model based on density (SMD) \cite{Marenich2009} with water as solvent; the results presented below correspond to SMD as it is better correlated with experimental values

Kinetic Properties of Aqueous Organic Redox Flow Battery Anolytes Using the Marcus–Hush Theory

“…Comparing against the base structure DQ, E 0 values for 4,4′-DMDQ, 5,5′-DMDQ, and 6,6′-DMDQ derivatives decrease around 0.12 V, this variation is in agreement with that observed upon introducing methyl substituent groups onto the 2,2′-bipyridine core. 33 For (SPr) 2 2− -Vi 2+ and BTMAP +2 -Vi 2+ the opposite behavior is detected; that means, the electron-withdrawing effect of amino and sulfonate groups (having Hammett parameters of 0.86 and 0.30, respectively) 34 cancel the electron-donating abilities of the propyl chain (having a Hammett parameter of −0.06). 34 Then, we examined the MV adsorption process in terms of two theoretical models to shed light on some aspects.…”

Comparison of computational chemistry methods for the discovery of quinone-based electroactive compounds for energy storage

“…A total of 11 exchangecorrelation functionals, also including some of the D3 dispersion 59,60 corrected variants, are used for high-level OPT and SPE calculations. These functionals include LDA 57 , PBE 40,61 , PBE-D3 59 , BLYP 62 , BLYP-D3 59 , B3LYP 62,63 , B3LYP-D3 59 , PBE0 64 , PBE0-D3 59 , HSE06 65 , and M08-HX 39 . Due to computational costs, the DFT aqueous-phase geometry optimizations are performed only with the following functionals: PBE, B3LYP, and M08-HX.…”

Discovery of aza-aromatic anolytes for aqueous redox flow batteries via high-throughput screening

“…27,28 In addition, it has also been investigated as a candidate energy storage compound. 29 For the backbone structures with 5-membered rings (7)(8)(9)(10)(11)(12)(13)(14), the single C atoms that are positioned between the two N atoms of 2H-imidazole (7) and 2H-benzimidazole (11) molecules were substituted in turn with N, S, and O atoms, thereby generating two subsets (8-10 and 12-14) of heterocyclic backbones. The rest of the backbone structures (15-31) contain only 6membered rings, and were created by using the Elemental Enumeration tool of the Schrödinger Materials Science Suite (SMSS).…”

“…We found that the redox potentials of single ring backbone structures, 15 and 16, are quite similar to each other. However, they are spread over a wider range for molecules with two (17)(18)(19)(20)(21)(22) and three rings (23)(24)(25)(26)(27)(28)(29)(30)(31). The solvation energies for the backbone structures are also found to be a complex function of the size of the molecules and the distance between the backbone nitrogen atoms.…”