Solvent-triggered stereoselectivity of α,α-cyclopropanation of amino acids in the Ni(ii) chiral coordination environment

2020 ◽  
Vol 49 (25) ◽  
pp. 8636-8644 ◽  
Author(s):  
Oleg A. Levitskiy ◽  
Olga I. Aglamazova ◽  
Yuri K. Grishin ◽  
Ksenia A. Paseshnichenko ◽  
Vadim A. Soloshonok ◽  
...  
Keyword(s):  
Amino Acids ◽  
Redox Activity ◽  
Coordination Environment ◽  
Diastereomeric Complexes

Unexpected solvent-controlled increase in stereoselectivity of glycine cyclopropanation within chiral Ni(ii) coordination environment was observed and rationalized. Cyclopropanated diastereomeric complexes exhibit stereodependent redox-activity.

scholarly journals Redox Activity of Ce(IV)-Substituted Polyoxometalates toward Amino Acids and Peptides

2020 ◽  
Vol 59 (15) ◽  
pp. 10569-10577
Author(s):  
Shorok A. M. Abdelhameed ◽  
Laurens Vandebroek ◽  
Francisco de Azambuja ◽  
Tatjana N. Parac-Vogt
Keyword(s):  
Amino Acids ◽  
Redox Activity

Which Stereoinductor Is Better for Asymmetric Functionalization of α‐Amino Acids in a Nickel(II) Coordination Environment? Experimental and DFT Considerations

2020 ◽  
Vol 26 (31) ◽  
pp. 7074-7082 ◽  
Author(s):  
Oleg A. Levitskiy ◽  
Olga I. Aglamazova ◽  
Vadim A. Soloshonok ◽  
Hiroki Moriwaki ◽  
Tatiana V. Magdesieva
Keyword(s):  
Amino Acids ◽  
Coordination Environment

Redox activity of some non-innocent amino acids

2013 ◽  
Vol 144 (7) ◽  
pp. 937-949 ◽  
Author(s):  
Kristína Matelková ◽  
Katrin Ossberger ◽  
Juraj Hudák ◽  
Jaroslav Vatrál ◽  
Roman Boča ◽  
...  
Keyword(s):  
Amino Acids ◽  
Redox Activity

A rhodamine based “off-on” probe for selective detection of Hg(ii) and subsequent l-proline and 4-hydroxyproline discrimination

RSC Advances ◽  
2014 ◽  
Vol 4 (20) ◽  
pp. 10118-10122 ◽  
Author(s):  
Ajoy Pal ◽  
Bamaprasad Bag
Keyword(s):  
Amino Acids ◽  
Selective Detection ◽  
Dual Mode ◽  
Coordination Environment ◽  
Turn On

The Rhodamine derivatized probe 2 selectively coordinates with Hg(ii) ions to exhibit dual mode “turn-on” signaling, subsequently ‘turned-off’ with addition of l-proline, specific among various amino acids due to its favorable coordination environment.

scholarly journals A Computational Study on the Ca2+ Solvation, Coordination Environment, and Mobility in Electrolytes for Calcium Ion Batteries

2021 ◽  
Author(s):  
Saeid Biria ◽  
Shreyas Pathreeker ◽  
Ian Hosein
Keyword(s):  
Ionic Liquids ◽  
Calcium Ion ◽  
Performance Metrics ◽  
Computational Study ◽  
Low Cost ◽  
Ion Pairing ◽  
Redox Activity ◽  
Coordination Environment ◽  
Organic Mixtures ◽  
Alkyl Sulfonate

Calcium (ion) batteries are promising next-generation energy storage systems, owing to their numerous benefits in terms of performance metrics, low-cost, mineral abundance, and economic sustainability. A central and critical area to the advancement of the technology is the development of suitable eletrolytes that allow for good salt solubility, ion mobility, electrochemical stability, and reversible redox activity. At this time, the study of different solvent-salt combinations is very limited. Here, we present a computational study on the coordination environment, solvation energetics, and diffusivity of calcium ions over a range of pertinent ionic liquids, cyclic and acylic alkyl carbonates, and specific alkyl nitriles and alkyl formamides, using the salts calcium bis(trifluoromethylsulfonyl)imide (Ca(TFSI)2) and calcium perchlorate (Ca(ClO4)2). Key findings are that several solvents from different solvent classes present comparable solvation environments and mobilities. Ca(TFSI)2 is prefered over Ca(ClO4)2 owing to the former’s mix coordination of Ca2+ to O and N atoms. Ionic liquids with alkyl sulfonate anions provide better coordation over TFSI, which leads to greater diffusivity. Binary organic mixtures (carbonates) provide the best solvation of Ca2+, however, single organic solvents also provide good solvation, such as EC, THF and DMF, as well as some acyclic carbonates. Ion pairing with the salt anion is always present, but can be mitigated through solvent selection, which also correlates to greater mobility; however, there are examples in which strong ion pairing is not significantly adverse to diffusivity. The solvent incorporate into the solvation structure with binary organic mixtures correlates well with the solvation capabilities of the individual solvents. Finally, we show that ionic liquids (specifically alkyl imidazole (cation) alkyl sulfonate (anion) ionic liquids) do not decompose when coordinating at a Ca metal interface, which indicates its promising stability. Overall, this study contributes further generalized understanding of the correlation between solvent and salt and the resultant Ca2+ complexes and Ca2+ mobility in a range of electrolytes, and reveals a range of possible solvents suitable for exploration in calcium (ion) batteries.

scholarly journals A Computational Study on the Ca2+ Solvation, Coordination Environment, and Mobility in Electrolytes for Calcium Ion Batteries

2021 ◽  
Author(s):  
Saeid Biria ◽  
Shreyas Pathreeker ◽  
Ian D. Hosein
Keyword(s):  
Ionic Liquids ◽  
Calcium Ion ◽  
Performance Metrics ◽  
Computational Study ◽  
Low Cost ◽  
Ion Pairing ◽  
Redox Activity ◽  
Coordination Environment ◽  
Organic Mixtures ◽  
Alkyl Sulfonate

Calcium (ion) batteries are promising next-generation energy storage systems, owing to their numerous benefits in terms of performance metrics, low-cost, mineral abundance, and economic sustainability. A central and critical area to the advancement of the technology is the development of suitable eletrolytes that allow for good salt solubility, ion mobility, electrochemical stability, and reversible redox activity. At this time, the study of different solvent-salt combinations is very limited. Here, we present a computational study on the coordination environment, solvation energetics, and diffusivity of calcium ions over a range of pertinent ionic liquids, cyclic and acylic alkyl carbonates, and specific alkyl nitriles and alkyl formamides, using the salts calcium bis(trifluoromethylsulfonyl)imide (Ca(TFSI)2) and calcium perchlorate (Ca(ClO4)2). Key findings are that several solvents from different solvent classes present comparable solvation environments and mobilities. Ca(TFSI)2 is prefered over Ca(ClO4)2 owing to the former’s mix coordination of Ca2+ to O and N atoms. Ionic liquids with alkyl sulfonate anions provide better coordation over TFSI, which leads to greater diffusivity. Binary organic mixtures (carbonates) provide the best solvation of Ca2+, however, single organic solvents also provide good solvation, such as EC, THF and DMF, as well as some acyclic carbonates. Ion pairing with the salt anion is always present, but can be mitigated through solvent selection, which also correlates to greater mobility; however, there are examples in which strong ion pairing is not significantly adverse to diffusivity. The solvent incorporate into the solvation structure with binary organic mixtures correlates well with the solvation capabilities of the individual solvents. Finally, we show that ionic liquids (specifically alkyl imidazole (cation) alkyl sulfonate (anion) ionic liquids) do not decompose when coordinating at a Ca metal interface, which indicates its promising stability. Overall, this study contributes further generalized understanding of the correlation between solvent and salt and the resultant Ca2+ complexes and Ca2+ mobility in a range of electrolytes, and reveals a range of possible solvents suitable for exploration in calcium (ion) batteries.

Homochirality as the Signature of Extra-Terrestrial Life

1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Optical Rotation ◽  
Physical Origin ◽  
Natural Choice ◽  
Rosetta Mission ◽  
Terrestrial Life ◽  
Subsurface Layers ◽  
Solar System Bodies ◽  
Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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