modernbrazerzkidai.blogg.se - Chromium chloride

First Synthesis of a Eunicellin Diterpene" J.

"Enantioselective Total Synthesis of (−)-7-Deacetoxyalcyonin Acetate. (b) Alois Fürstner, "Carbon−Carbon Bond Formations Involving Organochromium(III) Reagents" Chemical Reviews, 1999, 99 (4), 991–1046 doi: 10.1021/cr9703360 "Chromium(II) Chloride" in Encyclopedia of Reagents for Organic Synthesis John Wiley & Sons: New York 2005. Handbook of Preparative Inorganic Chemistry.

^ a b Riley, edited by Georg Brauer translated by Scripta Technica, Inc.

^ a b "MSDS of Chromium(II) chloride".

^ a b c Sigma-Aldrich Co., Chromium(II) chloride.

Zeitschrift für anorganische und allgemeine Chemie. "Struktur und Eigenschaften des blauen Chrom(II)-chlorid-tetrahydrats CrCl 2.4H 2O". "The crystal structure of chromium(II) chloride". CRC Handbook of Chemistry and Physics (90th ed.). It is also used in the Takai olefination to form vinyl iodides from aldehydes in the presence of iodoform. It is a reagent in the Nozaki-Hiyama-Kishi reaction, a useful method for preparing medium-size rings. The moderate electronegativity of chromium and the range of substrates that CrCl 2 can accommodate make organochromium reagents very synthetically versatile.

Alkyl halides and nitroaromatics are reduced by CrCl 2. Since the reduction potential of H + to H 2 in acidic conditions is +0.00, the chromous ion has sufficient potential to reduce acids to hydrogen, although this reaction does not occur without a catalyst.Ĭhromium(II) chloride is used as precursor to other inorganic and organometallic chromium complexes. The reduction potential for Cr 3+ + e − ⇄ Cr 2+ is −0.41. The molecular geometry is approximately octahedral consisting of four short Cr-O bonds (2.078 Å) arranged in a square planar configuration and two longer Cr-Cl bonds (2.758 Å) in a trans configuration. The hydrated derivative, CrCl 2(H 2O) 4, forms monoclinic crystals with the P2 1/c space group. īall-and-stick model of chromium(II) chloride tetrahydrate. The Cr centres are octahedral, being distorted by the Jahn-Teller Effect. It crystallizes in the Pnnm space group, which is an orthorhombically distorted variant of the rutile structure making it isostructural to calcium chloride. Cr + n H 2O + 2 HCl → CrCl 2(H 2O) n + H 2 Structure and properties Īnhydrous CrCl 2 is white however commercial samples are often grey or green. Treatment of chromium powder with concentrated hydrochloric acid gives a blue hydrated chromium(II) chloride, which can be converted to a related acetonitrile complex. On the laboratory scale, LiAlH 4, zinc, and related reductants produce chromous chloride from chromium(III) precursors:Ĥ CrCl 3 + LiAlH 4 → 4 CrCl 2 + LiCl + AlCl 3 + 2 H 2 2 CrCl 3 + Zn → 2 CrCl 2 + ZnCl 2ĬrCl 2 can also be prepared by treating a solution of chromium(II) acetate with hydrogen chloride: Cr 2(OAc) 4 + 4 HCl → 2 CrCl 2 + 4 AcOH CrCl 2 is produced by reducing chromium(III) chloride either with hydrogen at 500 ☌: