Copper chromite 2698205 170674669 2007-11-11T03:23:55Z 209.183.32.47 fix link '''Copper chromite''' is a complex inorganic composition Cu<sub>2</sub>Cr<sub>2</sub>O<sub>5</sub>, but often containing barium oxide that is used to catalyse certain reactions in [[organic synthesis]].<ref>Cladingboel, D. E. “Copper Chromite” in Encyclopedia of Reagents for Organic Synthesis 2001 John Wiley & Sons. DOI: 10.1002/047084289X.rc221</ref> It was first described in 1908.<ref>Gröger, M. “Über Ammoniumdoppelchromate” Zeitschrift fur anorganische Chemie volume 58, page 412-426 (1908).{{DOI|10.1002/zaac.19080580138}}; “Chromite aus basischen Chromaten” ibid. volume 76, page 30-38 (1912). {{DOI| 10.1002/zaac.19120760103}}</ref> A variety of composition are recognized including Cr<sub>2</sub>CuO<sub>4</sub>·CuO·BaCrO<sub>4</sub> [[chemical abstracts registry number is 99328-50-4) and Cr2Cu2O5 (CAS# 12053-18-8). The latter is sometimes intentionally poisoned with quinoline, when the catalyst is used for [[decarboxylation]] reactions. The catalyst was developed in North America by [[Homer Burton Adkins|Adkins]] and Lazier partly based on interrogation of [[Germany|German]] chemists after [[World War II]] in relation to the [[Fischer-Tropsch process]].<ref>[http://www.fischer-tropsch.org/primary_documents/gvt_reports/USNAVY/tech_rpt_248_45/tech_rpt_248_45_sec6.htm Fischer-Tropsch Archive] </ref> The catalyst Cr<sub>2</sub>CuO<sub>4</sub>·CuO·BaCrO<sub>4</sub> is prepared by addition of a solution containing both [[barium nitrate]] and [[copper(II) nitrate]] to a solution of ammonium [[chromate]]. This resulting precipitate is [[calcine]]d at 350-400 C.<ref>Lazier, W. A.; H. R. Arnold, H. “Copper Chromite Catalyst” Organic Syntheses, Collected Volume 2, p. 142 (1943). http://www.orgsyn.org/orgsyn/pdfs/CV2P0142.pdf.</ref> ==Illustrative reactions== *[[hydrogenation]] of [[ester]] compounds to the corresponding [[alcohol]]s. For example, sebacion, derived from the [[acyloin condensation]] of [[Sebacic acid|dimethyl sebacate]], is hydrogenated to 1,2-cyclodecanediol by this catalyst.<ref> Blomquist, A. T.; Goldstein, A. "1,2-Cyclodecanediol" [[Organic Syntheses]] Collected Volume 4, p.216. http://www.orgsyn.org/orgsyn/pdfs/cv4p0216.pdf</ref> [[Phenanthrene]] is also reduced, at the 9,10 position. * [[hydrogenolysis]] of [[2-fufuryl alcohol]] to [[1,5-Pentanediol|1,5-pentanediol]] at 250-300 °C under 3300-6000 psi of H<sub>2</sub>.<ref> Kaufman, D.; Reeve, W. “1,5-Pentanediol” Organic Syntheses, Collected Volume 3, p.693 (1955). http://www.orgsyn.org/orgsyn/pdfs/CV3P0693.pdf</ref> *[[decarboxylation]] of &alpha;-phenylcinnamic acid to ''cis''-[[stilbene]].<ref>Buckles, R. E.; Wheeler, N. C. “cis-Stilbene” Organic Syntheses, Collected Volume 4, p.857 (1963). http://www.orgsyn.org/orgsyn/pdfs/CV4P0857.pdf</ref> Reactions involving hydrogen are conducted at relatively high gas pressure (135 [[Atmosphere (unit)|atm]]) and high temperatures (150-300 [[°C]]) in a so-called hydrogenation bomb. More active catalysts requiring less vigrous conditions are known but are typically derived from more expensive metals, such as [[platinum]]. ==References== <references/> == External links == * [http://www.chempensoftware.com/reactions/RXN004.htm chempensoftware.com examples] == References == # {{Note|1}} ''The Copper-Chromium Oxide Catalyst for Hydrogenation'' Homer Adkins, Edward E. Burgoyne, Henry J. Schneider [[J. Am. Chem. Soc.]]; '''1950'''; 72(6); 2626-2629. [http://pubs.acs.org/cgi-bin/abstract.cgi/jacsat/1950/72/i06/f_ja01162a079.pdf First Page] # {{Note|2}} [[CAS registry]] [7440-47-3] & [1317-38-0] [[category:reagents for organic chemistry]] [[fr:Catalyseur et réaction d'Adkins]]