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Lewis Acid/Base Interaction Matrix Database

s-LUMO Lewis Acids

Group I & II Metal Cations

Search for s-Lewis acid species in The Chemical Thesaurus

FMO Topology:

The s-Lewis acids are the cations of the Group I alkali and Group II alkaline earth metals.

The shell-like LUMO (2s, 3s 4s 5s & 6s AOs) is superimposed upon a sphere of closed electron shells which defines the ionic radius of the cation.

Charge: Positive
HSAB: Intrinsically hard. Fajan's rules indicate that small highly charged cations, for example Be2+, are able to polarise anions and give polar covalent complexes.
Chemistry: Used as counter ions or spectator ions to interesting Lewis bases. Very important biochemical species.
Congeneric Series:

There are two s-LUMO series:

Group I alkali metals: Li+  Na+   K+   Rb+   Cs+
Group II alkali earth metals: Be2+   Mg2+  Ca2+   Sr2+   Ba2+

s-LUMO Lewis acid (generic)
Barium ion

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Beryllium ion

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Calcium ion

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Cesium cation

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Lithium ion

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Magnesium ion

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Potassium ion

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Rubidium cation

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Sodium ion

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Strontium ion

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Poster Nucleophiles & Bases

© Mark R. Leach 1999 –

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