Computational Redox Potential Predictions: Applications to Inorganic and Organic Aqueous Complexes, and Complexes Adsorbed to Mineral Surfaces

Krishnamoorthy Arumugam; Udo Becker

doi:10.3390/min4020345

A view of reactions at mineral surfaces from the aqueous phase

Mineralogical Magazine ◽

10.1180/002646101300119439 ◽

2001 ◽

Vol 65 (3) ◽

pp. 323-337 ◽

Cited By ~ 10

Author(s):

W. H. Casey

Keyword(s):

Exchange Reaction ◽

Ligand Exchange ◽

Reaction Rates ◽

Mineral Dissolution ◽

Mineral Surfaces ◽

Exchange Reactions ◽

Ligand Exchange Reaction ◽

Molecular Information ◽

Aqueous Complexes ◽

Oxygen Bond

AbstractThe processes by which a metal–oxygen bond dissociates in aqueous complexes are discussed and the reactions related to more complicated pathways of mineral dissolution. The dissolution of oxide minerals, and in fact many other classes of surface reactions, can be viewed as a ligand-exchange reaction because the bridging oxygens that link the metal to the mineral are progressively replaced by non-bridging functional groups. These ligand-exchange reactions are accelerated by protonations, hydroxylations and ligand substitutions that modify the lability of surface oxygens, but always at specific sites. Molecular information is important because reactions at some sites retard rates while reaction at other sites enhance them. Virtually all of the important variables that affect these reaction rates are local.

Download Full-text

Bonding and reactivity at oxide mineral surfaces from model aqueous complexes

Nature ◽

10.1038/35006036 ◽

2000 ◽

Vol 404 (6776) ◽

pp. 379-382 ◽

Cited By ~ 82

Author(s):

Brian L. Phillips ◽

William H. Casey ◽

Magnus Karlsson

Keyword(s):

Mineral Surfaces ◽

Oxide Mineral ◽

Aqueous Complexes

Download Full-text

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090634 ◽

1976 ◽

Vol 34 ◽

pp. 130-131

Author(s):

V.K. Berry

Keyword(s):

Oxidation Reaction ◽

Electron Microscope Study ◽

Elemental Sulfur ◽

Thiobacillus Ferrooxidans ◽

Physical Contact ◽

Metal Sulfides ◽

Low Grade ◽

Mineral Surfaces ◽

Mineral Surface ◽

Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

Download Full-text

Redox potential of the small intestine lumer in a model of experimental hemorrhage in rats

Gastroenterology ◽

10.1016/s0016-5085(01)80968-9 ◽

2001 ◽

Vol 120 (5) ◽

pp. A195-A195

Author(s):

J PAULA ◽

E SPINEDI ◽

A DUBIN ◽

D BUSTOS ◽

J DAVOLOS

Keyword(s):

Small Intestine ◽

Redox Potential

Download Full-text

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

Marine Ecology Progress Series ◽

10.3354/meps10407 ◽

2013 ◽

Vol 487 ◽

pp. 7-13 ◽

Cited By ~ 17

Author(s):

TG Gerwing ◽

AMA Gerwing ◽

D Drolet ◽

DJ Hamilton ◽

MA Barbeau

Keyword(s):

Redox Potential ◽

Intertidal Mudflat ◽

Mudflat Sediments

Download Full-text

Inorganic and organic chemical characteristics and sources of suspended particulate matters in Ulaanbaatar, Mongolia

GEOCHEMICAL JOURNAL ◽

10.2343/geochemj.2.0579 ◽

2020 ◽

Vol 54 (4) ◽

pp. 267-276

Author(s):

Koshi Yamamoto ◽

Yuta Suzuki ◽

Gochoobazar Oyunjargal ◽

Hiroyuki Fukuda ◽

Munkhtsetseg Oidov ◽

...

Keyword(s):

Organic Chemical ◽

Chemical Characteristics ◽

Particulate Matters ◽

Suspended Particulate ◽

Suspended Particulate Matters ◽

Inorganic And Organic

Download Full-text

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

10.26434/chemrxiv.12170136.v2 ◽

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.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

Aryl-substituted Triarsiranes: Synthesis and Reactivity

10.26434/chemrxiv.13176842 ◽

2020 ◽

Author(s):

André Schumann ◽

Jonas Bresien ◽

Malte Fischer ◽

Christian Hering-Junghans

Keyword(s):

Organic Chemistry ◽

Electronic Structure ◽

Heterocyclic Carbenes ◽

Synthetic Approaches ◽

Inorganic And Organic

Cyclotriarsanes are rare and limited synthetic approaches have hampered reactivity studies on these systems. Described in here is a scalable synthetic protocol towards (AsAr)3 (Ar = Dip, 2,6-iPr2-C6H3; Tip, 2,4,6-iPr3-C6H2), which allowed to study their reactivity towards [Cp2Ti(C2(SiMe3)2], affording titanocene diarsene complexes and towards N-heterocyclic carbenes (NHCs) to give straightforward access to a variety of NHC-arsinidene adducts. The electronic structure of the titanium diarsene complxes has been studied and they are best described as Ti(IV) species with a doubly reduced As2Ar2 ligand. These findings will make (AsAr)3 valuable precursors in the synthetic inorganic and organic chemistry.

Download Full-text