Coordination site-dependent cation binding and multi-responsible redox properties of Janus-head metalloligand, [MoV(1,2-mercaptophenolato)3]

2012 ◽  
Vol 41 (27) ◽  
pp. 8303 ◽  
Author(s):  
Takeshi Matsumoto ◽  
Masanori Wakizaka ◽  
Hirokazu Yano ◽  
Atsushi Kobayashi ◽  
Ho-Chol Chang ◽  
...  
Keyword(s):  
Redox Properties ◽  
Cation Binding ◽  
Coordination Site

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

Adhesion and Growth of Anaerobic Biofilms on Ion Exchange Resins

1986 ◽  
Vol 21 (4) ◽  
pp. 486-495 ◽  
Author(s):  
R.F.G. Selle Sardi ◽  
W. Bulani ◽  
W.L. Cairns ◽  
N. Kosaric
Keyword(s):  
Metabolic Activity ◽  
Cation Binding ◽  
Fatty Acid Substrate ◽  
Anaerobic Reactors ◽  
Initial Adhesion ◽  
Rapid Changes ◽  
Exchange Resins ◽  
Biofilm Development ◽  
First Time ◽  
Acid Substrate

Abstract Ion exchanger beads are explored as aids in accelerating the development of anaerobic biofilms for use in advanced anaerobic reactors. Initial adhesion and subsequent changes in adhesion and growth of anaerobic biofilms (as reflected in total supported biomass and metabolic activity) were monitored on different ion exchangers (strong cation, strong anion and weak anion) over a period of 12 days. Metabolic activity was recorded for the first time in this type of study using ATP biolumininescence assays which allowed monitoring of rapid changes in the biofilm development. Results indicate that the strong cation exchanger is a better overall substratum for anaerobic biofilm development due to its favorable property of dialent cation binding and adsorption of volatile fatty acid substrate for methanogens.

Synthesis and Cation Binding Properties of p-Tert-butyl-calix[4]arene Bearing 8-Hydroxyquinoline Units

2018 ◽  
Vol 15 (12) ◽  
pp. 1037-1041
Author(s):  
Slim Mannai ◽  
Yang Kim ◽  
Abdullah Sulaiman Al-Ayed ◽  
Lassaad Baklouti ◽  
Abdelwaheb Hamdi
Keyword(s):  
Cation Binding ◽  
Binding Properties ◽  
Tert Butyl

Polymer oxidation catalyst containing acidic functional groups

1981 ◽  
Vol 46 (5) ◽  
pp. 1237-1247
Author(s):  
Zdeněk Prokop ◽  
Karel Setínek
Keyword(s):  
Functional Groups ◽  
Elevated Temperatures ◽  
Redox Properties ◽  
Oxidation Catalyst ◽  
Carbon Clusters ◽  
Oxidation Activity ◽  
Redox Sites ◽  
Styrene Divinylbenzene ◽  
Proportional Decrease ◽  
Polymer Oxidation

The catalyst containing redox sites in addition to acid functional groups was prepared by sulphonation of a macroporous chloromethylated styrene-divinylbenzene copolymer with concentrated sulphuric acid at elevated temperatures. Its activity was tested for the oxidation of 2-propanol by molecular oxygen at 120 °C and was found to be comparable to that of the iridium on carbon catalyst.Neutralisation of acid functional groups by alkali metal led to proportional decrease in the oxidation activity. The results of EPR spectroscopic study of these catalysts show that the redox properties of the polymer are caused by carbon clusters which are capable of electron exchange.

Solvation and redox properties of [Co(en)3]3+-[Co(en)3]2+ system

1980 ◽  
Vol 45 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Adéla Kotočová ◽  
Ulrich Mayer
Keyword(s):  
Hydrogen Bond ◽  
Lewis Acid ◽  
Specific Interaction ◽  
Redox Properties ◽  
Solvation Effect ◽  
Interacting Particles ◽  
Acid Base ◽  
Polar Solvents ◽  
Oxidation Reduction ◽  
Solvent Molecules

The solvation effect of a number of nonaqueous polar solvents was studied on the oxidation-reduction properties of the [Co(en)3]3+-[Co(en)3]2+ system. Interactions of these ions with the solvent molecules are discussed in terms of their coordination, which is accompanied by a specific interaction of the Lewis acid-base type, namely formation of a hydrogen bond between the interacting particles. This is the main controlling factor of the redox properties of the studied system.

Influence of Metal Core Composition on Redox Properties and Photoreactivity of the Clusters [H4-xRu4-xRhx(CO)12] (x = 0, 2, 3, 4)

2001 ◽  
Vol 66 (7) ◽  
pp. 1062-1077 ◽  
Author(s):  
Maarten J. Bakker ◽  
Tapani A. Pakkanen ◽  
František Hartl
Keyword(s):  
Electrochemical Properties ◽  
Electrochemical Reduction ◽  
Redox Properties ◽  
Metal Core ◽  
Loss Product ◽  
Condensation Reactions ◽  
Core Composition ◽  
Co Dissociation ◽  
Major Reduction

Electrochemical properties of tetrahedral clusters [H2Ru2Rh2(CO)12], [HRuRh3(CO)12] and [Rh4(CO)12] were investigated in order to evaluate the influence of metal core composition in the series [H4-xRu4-xRhx(CO)12] (x = 0-4). The cluster [H3Ru3Rh(CO)12] was not available in sufficient quantities. As reported for [H4Ru4(CO)12], electrochemical reduction of the hydride-containing clusters [H2Ru2Rh2(CO)12] and [HRuRh3(CO)12] also results in (stepwise) loss of hydrogen, producing the anions [HRu2Rh2(CO)12]-, [Ru2Rh2(CO)12]2- and [RuRh3(CO)12]-. These anions can also be prepared from the neutral parent clusters via chemical routes. Electrochemical reduction of [Rh4(CO)12] does not result in the formation of any stable tetranuclear anion. Instead, [Rh5(CO)15]- and [Rh6(CO)15]2- are the major reduction products detected in the course of IR spectroelectrochemical experiments. Most likely, these cluster species are formed from the secondary CO-loss product [Rh4(CO)11]2- by fast redox condensation reactions. Their reoxidation regenerates parent [Rh4(CO)12], together with some [Rh6(CO)16]. Unlike [H4Ru4(CO)12] that undergoes photochemical CO-dissociation, [H2Ru2Rh2(CO)12] and [Rh4(CO)12] are completely photostable in neat hexane and dichloromethane as well as in the presence of oct-1-ene.

Electrochemiluminescence of Ruthenium(II) Complexes Functionalized with Crown Ether Pendants and Effects of Cation Binding

2008 ◽  
Vol 47 (3) ◽  
pp. 1218-1223 ◽  
Author(s):  
Mei-Jin Li ◽  
Zuofeng Chen ◽  
Nianyong Zhu ◽  
Vivian Wing-Wah Yam ◽  
Yanbing Zu
Keyword(s):  
Crown Ether ◽  
Cation Binding

Nonoxido Vanadium(IV) Compounds Involving Dithiocarbazate-Based Tridentate ONS Ligands: Synthesis, Electronic and Molecular Structure, Spectroscopic and Redox Properties

2015 ◽  
Vol 54 (13) ◽  
pp. 6203-6215 ◽  
Author(s):  
Sanchita Kundu ◽  
Dhrubajyoti Mondal ◽  
Kisholoy Bhattacharya ◽  
Akira Endo ◽  
Daniele Sanna ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Redox Properties
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