1271-24-5 Usage
Chemical Properties
bordeaux crystalline powder
Uses
Provides catalyst for ethylene polymerization. A precursor to other chromium(II) compounds.
General Description
Red needles or reddish-purple solid.
Air & Water Reactions
Chromocene is very sensitive to exposure to air and moisture (decomposition is not vigorous). Decomposes in water .
Reactivity Profile
Chromocene reacts with water and alcohols. . It's reaction with alcohols produces pyrophoric metal alkoxides (dialkoxychromium and cyclopentadiene).
Fire Hazard
Literature sources indicate that Chromocene is flammable.
Purification Methods
Chromocene forms pyrophoric red crystals on sublimation at 50o/0.1mm followed by resublimation at 75-90o/0.1mm. Although it is stable at least to 300o, it is readily oxidised in air, and effervesces slowly in H2O to give cyclopentadiene. All operations should be carried out in a dry box. It decomposes in CCl4 or CS2, and for IR even grinding with nujol, KBr or KI causes some decomposition. [Wilkinson et al. J Inorg Nucl Chem 95 109 1956, Wilkinson J Am Chem Soc 76 209 1954, Beilstein 16 IV 1774.]
Check Digit Verification of cas no
The CAS Registry Mumber 1271-24-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,2,7 and 1 respectively; the second part has 2 digits, 2 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 1271-24:
(6*1)+(5*2)+(4*7)+(3*1)+(2*2)+(1*4)=55
55 % 10 = 5
So 1271-24-5 is a valid CAS Registry Number.
InChI:InChI=1/2C5H5.Cr/c2*1-2-4-5-3-1;/h2*1-5H;/q-5;-1;
1271-24-5Relevant articles and documents
A facile access to CpCr (acac)Cl and related systems
Heinemann, Oliver,Jolly, Peter W.,Krueger, Carl,Verhovnik, Glenn P.J.
, p. 477 - 479 (1998)
CpCr(acac)Cl has been prepared by reacting CpCr(THF)Cl2 with sodium acetylacetonate. Related Cr compounds containing the C5Me5 group and ethylacetoacetate have also been studied. Catalysts active for the polymerization of ethylene are obtained by treating these compounds with aluminium alkyls while the title compound reacts with Et2AlCl or Et3Al to give [CpCr(μ-Cl)Et]2.
Wilkinson, G.
, p. 209 - 211 (1954)
Ein μ2-Benzylidenkomplex des Chroms mit ungepaarten Elektronen
Koehler, F. H.,Krueger, C.,Zeh, H.
, p. C13 - C15 (2007/10/02)
The benzylidene-bridged dichromium complex 2(μ-Br)2(μ-CHC6H5) (4) has been obtained by thermolysis of 2(μ-Br)2. 1H NMR spectroscopy shows that 4 is antiferromagnetic and a barier of 64.0 kJ mol-1 slows down the rotation of the phenyl group.