New Alkali-Metal Gallium Selenites, AGa(SeO3)2 (A = Li, Na, K, and Cs): Effect of Cation Size on the Framework Structures and Macroscopic Centricities

2013 ◽  
Vol 52 (9) ◽  
pp. 5176-5184 ◽  
Author(s):  
Dong Woo Lee ◽  
Kang Min Ok
Keyword(s):  
Alkali Metal ◽  
Cation Size

The Influence of Alkali Metal Cation Size on the Formation and Dissociation of Crown Ether Fullerene Dimers in Electrospray Mass Spectrometry

2015 ◽  
Vol 120 (1) ◽  
pp. 786-792 ◽  
Author(s):  
Ina D. Kellner ◽  
Marc S. von Gernler ◽  
Manolis D. Tzirakis ◽  
Michael Orfanopoulos ◽  
Thomas Drewello
Keyword(s):  
Mass Spectrometry ◽  
Crown Ether ◽  
Alkali Metal ◽  
Metal Cation ◽  
Electrospray Mass Spectrometry ◽  
Alkali Metal Cation ◽  
Fullerene Dimers ◽  
Cation Size

A cation size effect on the framework structures in ABi2SeO3F5 (A = K and Rb): first examples of alkali metal bismuth selenite fluorides

2018 ◽  
Vol 47 (18) ◽  
pp. 6598-6604 ◽  
Author(s):  
Shuangshuang Shi ◽  
Min Luo ◽  
Chensheng Lin ◽  
Ning Ye
Keyword(s):  
Alkali Metal ◽  
Size Effect ◽  
Hydrothermal Method ◽  
Cation Size

First examples of alkali metal bismuth selenite fluorides, ABi2SeO3F5 (A = K, Rb), have been synthesized through a soft hydrothermal method.

scholarly journals Bonding in Group 1 Citrate Salts

2014 ◽  
Vol 70 (a1) ◽  
pp. C655-C655
Author(s):  
James Kaduk ◽  
Alagappa Rammohan
Keyword(s):  
Hydrogen Bonds ◽  
Alkali Metal ◽  
Weak Interactions ◽  
Alkali Metal Cation ◽  
Quantitative Measure ◽  
Electrostatic Energy ◽  
Hydroxyl Groups ◽  
Local Environments ◽  
The Stability ◽  
Cation Size

Computational studies of > 15 new crystal structures and the 10 previously-reported structures of alkali metal citrates provide insight into why the atoms are where they are. The metal-citrate bonding is predominantly ionic, with very little covalent character, which decreases as the cation size increases. Bond valence calculations indicate that most cations are crowded, and that the crowding decreases as the cation size increases. Although most oxygen atoms coordinate to the metals, a few do not, and they tend to be the least-negative oxygens. Both the citrate hydroxyl groups and water molecules tend to bridge two cations, and the carboxylate coordination is more varied. The solid state energy differences are dominated by differences in van der Waals and electrostatic energy contributions. In the Li and Na salts, the citrate anion occurs predominantly in a higher-energy "kinked" conformation, rather than the extended lowest-energy conformation observed in salts of the larger cations. Detailed conformational analysis of the citrate anions enables quantification of the conformational energy costs in these solids. Hydrogen bonding is important to the stability of these salts. The Mulliken overlap population in the hydrogen bonds provides a quantitative measure of their strength, and permits identification of long (weak) interactions which are significant in some of these compounds. Patterns in both the local environments of the hydrogen bonds and the more-extended features (graph sets) are noted. Polymorphs and sets of isostructural compounds permit more-detailed analysis of the structures and energetics in these compounds. The order of ionization of the three carboxylic acid groups is in general central/terminal/terminal, but there are two exceptions. While we have concentrated on salts containing a single alkali metal cation (and hydrogen), the structures of NaK2C6H5O7 and NaKHC6H5O7 provide an exciting window on a larger universe of mixed salts.

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