The Influence of Alkali Metal Ions on the Stability and Reactivity of Chromium(III) Superoxide Moieties Spanned by Siloxide Ligands

2019 ◽  
Vol 25 (22) ◽  
pp. 5743-5750 ◽  
Author(s):  
Marie‐Louise Wind ◽  
Santina Hoof ◽  
Christian Herwig ◽  
Beatrice Braun‐Cula ◽  
Christian Limberg
Keyword(s):  
Alkali Metal ◽  
Metal Ions ◽  
Alkali Metal Ions ◽  
The Stability

Complexation of Alkali Metal Ions by the Cryptand 4,7,13,16-Tetraoxa-1,10-diazabicyclo[8.8.5]tricosane in Several Solvents

1994 ◽  
Vol 47 (1) ◽  
pp. 123 ◽  
Author(s):  
R Dhillon ◽  
SF Lincoln
Keyword(s):  
Stability Constant ◽  
Alkali Metal ◽  
Metal Ions ◽  
Potentiometric Titration ◽  
Propylene Carbonate ◽  
Alkali Metal Ions ◽  
Factors Affecting ◽  
The Stability ◽  
Titration Study ◽  
Complexation Process

A potentiometric titration study of the complexation of metal ions (M+) by 4,7,13,16- tetraoxa-1,10-diazabicyclo[8.8.5] tricosane (C22C5) at 298.2 K and I = 0.05 (NEt4ClO4) yields log(K/dm3 mol-1) =6.07 and 5.36, 7.55 and 5.95, 6.26 and 7.56, 5.5 and 6.66, 4.57 and 5.16, and 8.14 and 14.51 when M+ = Li+, Na+, K+, Rb +, Cs+ and Ag+, respectively, where the first and second magnitudes of each pair refer to the stability constant (K) for [M(C22C5)]+ in acetonitrile and ropylene carbonate solvent, respectively. A 7Li n.m.r. tudy yields kd (298.2 K) = 428 s-1, ∆ Hd ‡ = 24.7 kJ mol-1 and ∆ Sd ‡ = -111 J K-1 mol-1 for the monomolecular decomplexation of Li+ from [Li(C22C5)]+, and kc(298.2 K) = 9.83×107 dm3 mol-1 s-1 for the complexation process in propylene carbonate. These data are compared with those for related systems and are discussed in terms of the factors affecting cryptate stability and lability.

Ion–peptide interactions between alkali metal ions and a termini-protected dipeptide: modeling a portion of the selectivity filter in K+ channels

2019 ◽  
Vol 21 (2) ◽  
pp. 561-571 ◽  
Author(s):  
Shun-ichi Ishiuchi ◽  
Yuta Sasaki ◽  
James M. Lisy ◽  
Masaaki Fujii
Keyword(s):  
Alkali Metal ◽  
Metal Ions ◽  
Selectivity Filter ◽  
Alkali Metal Ions ◽  
K Channels ◽  
Peptide Interactions

Differentiating K+ and Na+ binding patterns in peptide sequences.

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