Comparison of two methods of measuring the depth of the redox potential discontinuity in intertidal mudflat sediments

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [RuII(LR)(L)]0 (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [RuII(LR)(L)]0 shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl−. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

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Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

10.26434/chemrxiv.12170136.v1 ◽

2020 ◽

Author(s):

Vishwanath R.S ◽

Masa-aki Haga ◽

Takumi Watanabe ◽

Emilia Witkowska Nery ◽

Martin Jönsson-Niedziolka

Keyword(s):

Redox Potential ◽

Organic Phase ◽

Electron Donor ◽

Ion Transfer ◽

Neutral Complex ◽

Pyridine Ligand ◽

Electrochemical Testing ◽

Ru Complex ◽

Three Phase ◽

Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [RuII(LR)(L)]0 (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [RuII(LR)(L)]0 shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl−. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

Download Full-text

Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

10.26434/chemrxiv.12170136 ◽

2020 ◽

Author(s):

Vishwanath R.S ◽

Masa-aki Haga ◽

Takumi Watanabe ◽

Emilia Witkowska Nery ◽

Martin Jönsson-Niedziolka

Keyword(s):

Redox Potential ◽

Organic Phase ◽

Electron Donor ◽

Ion Transfer ◽

Neutral Complex ◽

Pyridine Ligand ◽

Electrochemical Testing ◽

Ru Complex ◽

Three Phase ◽

Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [RuII(LR)(L)]0 (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [RuII(LR)(L)]0 shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl−. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

Download Full-text

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

10.26434/chemrxiv.7995935.v2 ◽

2019 ◽

Author(s):

Mariano Sánchez-Castellanos ◽

Martha M. Flores-Leonar ◽

Zaahel Mata-Pinzón ◽

Humberto G. Laguna ◽

Karl García-Ruiz ◽

...

Keyword(s):

Redox Potential ◽

Active Material ◽

Chemical Properties ◽

Small Subset ◽

Solubility In Water ◽

Protonation Reaction ◽

Redox Active ◽

Physico Chemical ◽

Pka Value ◽

Flow Batteries

Compounds from the 2,2’-bipyridine molecular family were investigated for use as redox-active materials in organic flow batteries. For 156 2,2’-bipyridine derivatives reported in the academic literature, we calculated the redox potential, the pKa for the first protonation reaction, and the solubility in aqueous solutions. Using experimental data on a small subset of derivatives, we were able to calibrate our calculations. We find that functionalization with electron-withdrawing groups leads to an increase of the redox potential and to an increase of the molecular acidity (as expressed in a reduction of the pKa value for the first protonation step). Furthermore, calculations of solubility in water indicate that some of the studied derivatives have adequate solubility for flow battery applications. Based on an analysis of the physico-chemical properties of the 156 studied compounds, we down-select five molecules with carbonyl- and nitro-based functional groups, whose parameters are especially promising for potential application as negative redox-active material inorganic flow batteries.

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

10.26434/chemrxiv.7995935 ◽

2019 ◽

Author(s):

Mariano Sánchez-Castellanos ◽

Martha M. Flores-Leonar ◽

Zaahel Mata-Pinzón ◽

Humberto G. Laguna ◽

Karl García-Ruiz ◽

...

Keyword(s):

Redox Potential ◽

Active Material ◽

Chemical Properties ◽

Small Subset ◽

Solubility In Water ◽

Protonation Reaction ◽

Redox Active ◽

Physico Chemical ◽

Pka Value ◽

Flow Batteries

Compounds from the 2,2’-bipyridine molecular family were investigated for use as redox-active materials in organic flow batteries. For 156 2,2’-bipyridine derivatives reported in the academic literature, we calculated the redox potential, the pKa for the first protonation reaction, and the solubility in aqueous solutions. Using experimental data on a small subset of derivatives, we were able to calibrate our calculations. We find that functionalization with electron-withdrawing groups leads to an increase of the redox potential and to an increase of the molecular acidity (as expressed in a reduction of the pKa value for the first protonation step). Furthermore, calculations of solubility in water indicate that some of the studied derivatives have adequate solubility for flow battery applications. Based on an analysis of the physico-chemical properties of the 156 studied compounds, we down-select five molecules with carbonyl- and nitro-based functional groups, whose parameters are especially promising for potential application as negative redox-active material inorganic flow batteries.

Download Full-text