Chromium(II) acetate

  • 628-52-4
  • 14976-80-8 ( hydrate)

Red solid

Fixed

1.79 g · cm -3

  • Practically insoluble in water and ether
  • Slightly soluble in ethanol

11260 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Chromium (II ) acetate is a chemical compound of the chromium from the group of acetates. It is usually present as dimeric dihydrate, thus contains two chromium ( II) ions, four acetate groups and two molecules of water.

History

The compound was first mentioned in 1844 in a paper by Eugene Peligot who noticed the blue from solutions of chromium ( II) compounds with the addition of potassium or sodium acetate red transparent crystals precipitated, which decomposed rapidly in air. It was not until 1950, however, was aware of the different binding mode compared to other chromium (II ) salts. 1953 erdeckte is that the compound is isomorphic to copper ( II) acetate hydrate.

Production and representation

Chromium (II ) acetate may be prepared by reacting a chromium ( II) compound (such as chromium (II ) chloride ) are obtained with sodium acetate.

When drying the hydrate at 100 ° C over phosphorus ( V) oxide to form the anhydrate.

Properties

Chromium (II ) acetate dimer dihydrate as a diamagnetic red solid with a monoclinic crystal structure. In this the two chromium atoms form between them from a very unusual for metals quadruple bond ( one σ, two π and one δ -electron bond ). This can be explained by the four unpaired electrons of the chromium ( II) ions, the acetate groups to stabilize the complex. The bond distance between the chromium ions is very short with 2.362 Å.

It is dry in air for a few hours, stored indefinitely under nitrogen. The drying over phosphorus pentoxide at 100 ° C results in the delivery of the complexed crystal water under color change to brown and increase the sensitivity to air.

Use

Chromium (II ) acetate is used as a reducing agent in organic synthesis.

It can also be used to prepare other chromium (II ) salts and for removing oxygen in gas analysis.

CAS registry number PubChem Dimer (chemistry) Chromium(II) chloride Monoclinic crystal system
188487
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