Lewis Acid/Base Interaction Matrix Database

Type 14 Lewis Acid/Base Complexation Chemistry
Friedel-Crafts Reagents

               Cl+      +      [AlCl4]              Cl+ [AlCl4]

Bonding: Charge controlled ionic complexes are highly reactive (transient) species which are prepared in solution where they show little or no ion pairing.
Charge: The charge on a Type 14 complex is always neutral.

Type 14 complexes include electrophilic haloenium ion or carbenium ion reagents with non-electrophilic counter ions.

Lobe-LUMO Lewis acids have a strong symbiotic affinity for halogen anion ligands, close in type to those they already possess. Thus:

•   AlCl3 has a high affinity for Cl to give [AlCl4]

•   FeBr3 has a high affinity for Br to give [FeBr4]

Type 14 complexes are not prepared from the cation plus anion, but from the dihalogen, organic halide or acyl halide plus halophilic Lewis acid:

              Cl2        +      AlCl3              Cl+   [AlCl4]
              R–Cl     +      AlCl3              
R+    [AlCl4]

The resulting Type 14 complexes act as sources of "naked" electrophilic Cl+, Br+ and R3C+, etc. that are able to undergo electrophilic aromatic substitution with benzene and other aromatics:

Congeneric Series: Few series.
Type 14 Lewis acid/base complex (generic)
Acyl cation/tetrachloroaluminate complex (generic)

more here
Bromine tetrabromoferrate

more here
Carbenium ion/tetrachloro aluminate complex (generic)

more here
Chlorine perchlorate

more here
Chlorine tetrachloroaluminate

more here
N5 hexafluoroarsinate

more here
Nitronium tetrafluoroborate

more here
Xenon fluoride hexafluoroplatinate(V)

more here

Interactions and reactions classified as:
      1 +1 1
      1 +1 1
      1 +1 1
      1 +1 1
      1 +1 1
      1 +1 1
      1 +1 1
      1 +1 1

Nucleophiles & Bases

© Mark R. Leach 1999-

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