scholarly journals Stereoselective polymerization of rac-lactide catalyzed by zwitterionic calcium complexes

2021 ◽  
Author(s):  
Na Liu ◽  
Doudou Liu ◽  
Bo Liu ◽  
Hao Zhang ◽  
Dongmei Cui
Keyword(s):  
Calcium Complexes

Two zwitterionic calcium complexes L1CaN(SiMe3)2(THF) (1) and L2CaN(SiMe3)2 (2) via protolysis reaction were synthesized. At −75 °C, 1 gave a heterotactic sequence enriched polylactide, whilst 2 produced an isotactic sequence enriched polymer.

Changes in the secondary structures and zeta potential of soybean peptide and its calcium complexes in cell membrane medium

2021 ◽  
Author(s):  
He Liu ◽  
Ying Lv ◽  
Jingting Xu ◽  
Chen Chen ◽  
Shuntang Guo
Keyword(s):  
Enzymatic Hydrolysis ◽  
Cell Membrane ◽  
Zeta Potential ◽  
Calcium Binding ◽  
Binding Capacity ◽  
Secondary Structures ◽  
High Calcium ◽  
Calcium Complexes

In this study, soybean peptides (10-30kDa) with high calcium binding capacity were prepared by enzymatic hydrolysis and ultrafiltration. The results of cell experiments showed that the peptide could transport calcium...

C–H and C–F coordination of arenes in neutral alkaline earth metal complexes

2021 ◽  
Author(s):  
Jacob S. McMullen ◽  
Alison J. Edwards ◽  
Jamie Hicks
Keyword(s):  
Metal Complexes ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Calcium Complexes ◽  
Group 2 ◽  
Rare Group

A series of neutral magnesium and calcium complexes bearing an extremely bulky diamido ligand have been synthesised and crystallographically characterised. A number of these complexes feaure rare group 2 metal···aromatic...

scholarly journals Molecular Properties of Bare and Microhydrated Vitamin B5–Calcium Complexes

2021 ◽  
Vol 22 (2) ◽  
pp. 692
Author(s):  
Davide Corinti ◽  
Barbara Chiavarino ◽  
Debora Scuderi ◽  
Caterina Fraschetti ◽  
Antonello Filippi ◽  
...  
Keyword(s):  
Gas Phase ◽  
Pantothenic Acid ◽  
Isomeric Form ◽  
Deprotonated Form ◽  
Linear Absorption ◽  
Vitamin B5 ◽  
Essential Nutrient ◽  
Calcium Complexes ◽  
Singly Charged ◽  
Phase Population

Pantothenic acid, also called vitamin B5, is an essential nutrient involved in several metabolic pathways. It shows a characteristic preference for interacting with Ca(II) ions, which are abundant in the extracellular media and act as secondary mediators in the activation of numerous biological functions. The bare deprotonated form of pantothenic acid, [panto-H]−, its complex with Ca(II) ion, [Ca(panto-H)]+, and singly charged micro-hydrated calcium pantothenate [Ca(panto-H)(H2O)]+ adduct have been obtained in the gas phase by electrospray ionization and assayed by mass spectrometry and IR multiple photon dissociation spectroscopy in the fingerprint spectral range. Quantum chemical calculations at the B3LYP(-D3) and MP2 levels of theory were performed to simulate geometries, thermochemical data, and linear absorption spectra of low-lying isomers, allowing us to assign the experimental absorptions to particular structural motifs. Pantothenate was found to exist in the gas phase as a single isomeric form showing deprotonation on the carboxylic moiety. On the contrary, free and monohydrated calcium complexes of deprotonated pantothenic acid both present at least two isomers participating in the gas-phase population, sharing the deprotonation of pantothenate on the carboxylic group and either a fourfold or fivefold coordination with calcium, thus justifying the strong affinity of pantothenate for the metal.

Calcium complexes determined by polarography

Talanta ◽  
1980 ◽  
Vol 27 (11) ◽  
pp. 971-976 ◽  
Author(s):  
H WHARTON
Keyword(s):  
Calcium Complexes

ChemInform Abstract: Calcium Complexes of Mixed Ligands: Ca2(acetate)4(HOH)2 and Ca1.5(salicylate)2(acetate)(HOH)2(acetic acid).

ChemInform ◽  
1988 ◽  
Vol 19 (34) ◽  
Author(s):  
R. HELEMS ◽  
L. B. COLE ◽  
E. M. HOLT
Keyword(s):  
Acetic Acid ◽  
Mixed Ligands ◽  
Calcium Complexes

Bibracchial diazatetralactams. Structure and molecular modeling of calcium complexes

1996 ◽  
Vol 385 (3) ◽  
pp. 167-174 ◽  
Author(s):  
Bernard Cathala ◽  
Claude Picard ◽  
Louis Cazaux ◽  
Pierre Tisnès
Keyword(s):  
Molecular Modeling ◽  
Calcium Complexes

Determination of formation constants of calcium complexes of difluoromethylenediphosphonic acid and related diphosphonates

1983 ◽  
Vol 55 (7) ◽  
pp. 1089-1094 ◽  
Author(s):  
Tekum. Fonong ◽  
Donald J. Burton ◽  
Donald J. Pietrzyk
Keyword(s):  
Formation Constants ◽  
Calcium Complexes

Mono- and Dinuclear Macrocyclic Calcium Complexes as Platforms for Mixed-Metal Complexes and Clusters

2015 ◽  
Vol 55 (2) ◽  
pp. 840-847 ◽  
Author(s):  
Emma A. Connolly ◽  
James W. Leeland ◽  
Jason B. Love
Keyword(s):  
Metal Complexes ◽  
Mixed Metal ◽  
Mixed Metal Complexes ◽  
Calcium Complexes

Correlating Calcium Electrodeposition with Solvation Structure: X-Ray Absorption Studies on Ethereal-Calcium Complexes in Solution

2020 ◽  
Vol MA2020-02 (4) ◽  
pp. 796-796
Author(s):  
Darren Driscoll ◽  
Nathan T Hahn ◽  
Mahalingam Balasubramanian
Keyword(s):  
X Ray ◽  
Absorption Studies ◽  
Solvation Structure ◽  
Calcium Complexes ◽  
X Ray Absorption
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