fbpx
Wikipedia

Organocadmium chemistry

An organocadmium compound is an organometallic compound containing a carbon to cadmium chemical bond. Organocadmium chemistry describes physical properties, synthesis, reactions and use of these compounds.[1] Cadmium shares group 12 with zinc and mercury and their corresponding chemistries have much in common. The synthetic utility of organocadmium compounds is limited.

The simplest organocadmium compound is dimethylcadmium. It is a linear molecule with a C-Cd bond length of 213 pm.[2] Organocadmium compounds are typically sensitive to air, light, and moisture.

Synthesis

 
Space-filling model of dimethylcadmium

Dimethylcadmium and diethylcadmium were reported in 1917 by Erich Krause. In general, they are prepared by transmetalation or by an exchange reaction between an alkylating agent and a cadmium salt.[3]

According to one procedure, diethylcadmium is produced the reaction of cadmium bromide with two equivalents of the Grignard reagent ethylmagnesium bromide in diethyl ether. Diethylcadmium is a colorless oil with melting point −21 °C. Diphenylcadmium can be prepared by the reaction of phenyllithium with cadmium bromide. Diphenylcadmium is a solid with a melting point of 174 °C.

Fluoroalkyl and alkenyl derivatives

Following established trends, perfluorinated alkyl and alkenyl derivatives of cadmium exhibit improved thermal stability. The alkenyl derivatives are generated by the addition of iodotrifluoroethylene to cadmium metal.[4]

Reactions

Organocadmium compounds are less nucleophilic than the organozincs. This reduced reactivity is demonstrated in the conversion of acyl chlorides to ketones with these reagents.[5] This reaction was reported by Henry Gilman in 1936 and was used until less toxic cuprates were available. The related Grignard reagent would react further, giving to the tertiary alcohol. Methyl cadmium was used in one of the steps leading to cholesterol total synthesis:[6]

 

Another synthetic use of an organocadmium is the reaction of diisoamylcadmium with β-carbomethoxypropionyl chloride to methyl 4-keto-7-methyloctanoate without reacting further with the ketone group or the ester group.[7]

This selectivity is observed provided that the reaction is carried out salt free.[8] When the cadmium reagent is generated in situ from a cadmium salt, the halide generates a more nucleophilic organocadmium reagent, an ate complex. The same salt effect can be observed with organozinc compounds.

Dimethylcadmium has been used to synthesize colloidal nanocrystals of II-VI materials such as cadmium selenide. Its toxic and volatile nature has led researchers to look elsewhere for cadmium precursors such as cadmium oxide.[9]

Toxicity

Cadmium compounds are toxic. Dimethylcadmium is toxic to the kidney, the liver, the central nervous system, and the respiratory organs when inhaled.[10] Cadmium compounds in general are considered to be carcinogen to humans by the IARC.[11]

References

  1. ^ Synthetic Methods of Organometallic and Inorganic Chemistry Vol 5, Copper, Silver, Gold, Zinc, Cadmium, and Mercury W.A. Herrmann Ed. ISBN 3-13-103061-5
  2. ^ Felix Hanke; Sarah Hindley; Anthony C. Jones; Alexander Steiner (2016). "The Solid State Structures of the High and Low Temperature Phases of Dimethylcadmium". Chemical Communications. 52 (66): 10144–10146. doi:10.1039/c6cc05851e. PMID 27457504.
  3. ^ Erich Krause (1917). "Einfache Cadmiumdialkyle. (I. Mitteilung über organische Cadmium-Verbindungen.)". Berichte der deutschen chemischen Gesellschaft. 50 (2): 1813–1822. doi:10.1002/cber.19170500292.
  4. ^ Burton, Donald J.; Yang, Zhen-Yu; Morken, Peter A. (1994). "Fluorinated organometallics: Vinyl, Alkynyl, Allyl, Benzyl, Propargyl and Aryl". Tetrahedron. 50 (10): 2993–3063. doi:10.1016/S0040-4020(01)81105-4.
  5. ^ David A. Shirley (2011). "The Synthesis of Ketones from Acid Halides and Organometallic Compounds of Magnesium, Zinc, and Cadmium". Org. Reactions. doi:10.1002/0471264180.or008.02.
  6. ^ Woodward, R. B.; Sondheimer, Franz; Taub, David; Heusler, Karl; McLamore, W. M. (1952). "The Total Synthesis of Steroids". Journal of the American Chemical Society. 74 (17): 4223–51. doi:10.1021/ja01137a001.
  7. ^ Cason, James; Proutyear=1948, Franklin S. "Methyl 4-Keto-7-Methyloctanoate". Organic Syntheses. 28: 75. doi:10.15227/orgsyn.028.0075.
  8. ^ Jones, Paul R.; Desio, Peter J. (1978). "The less familiar reactions of organocadmium reagents". Chemical Reviews. 78 (5): 491–516. doi:10.1021/cr60315a001.
  9. ^ Peng ZA, Peng X (2001). "Formation of high-quality CdTe, CdSe, and CdS nanocrystals using CdO as precursor". Journal of the American Chemical Society. 123 (1): 183–4. doi:10.1021/ja003633m. PMID 11273619.
  10. ^ Spiridonova EIa (1991). "[Experimental study of toxic properties of dimethylcadmium]". Gigiena Truda I Professional'nye Zabolevaniia (in Russian) (6): 14–7. PMID 1916391.
  11. ^ "Cadmium and Cadmium compounds". Arsenic, Metals, Fibres and Dusts. International Agency for Research on Cancer. 2012. pp. 121–145. ISBN 9789283201359.

organocadmium, chemistry, organocadmium, compound, organometallic, compound, containing, carbon, cadmium, chemical, bond, describes, physical, properties, synthesis, reactions, these, compounds, cadmium, shares, group, with, zinc, mercury, their, corresponding. An organocadmium compound is an organometallic compound containing a carbon to cadmium chemical bond Organocadmium chemistry describes physical properties synthesis reactions and use of these compounds 1 Cadmium shares group 12 with zinc and mercury and their corresponding chemistries have much in common The synthetic utility of organocadmium compounds is limited The simplest organocadmium compound is dimethylcadmium It is a linear molecule with a C Cd bond length of 213 pm 2 Organocadmium compounds are typically sensitive to air light and moisture Contents 1 Synthesis 1 1 Fluoroalkyl and alkenyl derivatives 2 Reactions 3 Toxicity 4 ReferencesSynthesis Edit Space filling model of dimethylcadmium Dimethylcadmium and diethylcadmium were reported in 1917 by Erich Krause In general they are prepared by transmetalation or by an exchange reaction between an alkylating agent and a cadmium salt 3 According to one procedure diethylcadmium is produced the reaction of cadmium bromide with two equivalents of the Grignard reagent ethylmagnesium bromide in diethyl ether Diethylcadmium is a colorless oil with melting point 21 C Diphenylcadmium can be prepared by the reaction of phenyllithium with cadmium bromide Diphenylcadmium is a solid with a melting point of 174 C Fluoroalkyl and alkenyl derivatives Edit Following established trends perfluorinated alkyl and alkenyl derivatives of cadmium exhibit improved thermal stability The alkenyl derivatives are generated by the addition of iodotrifluoroethylene to cadmium metal 4 Reactions EditOrganocadmium compounds are less nucleophilic than the organozincs This reduced reactivity is demonstrated in the conversion of acyl chlorides to ketones with these reagents 5 This reaction was reported by Henry Gilman in 1936 and was used until less toxic cuprates were available The related Grignard reagent would react further giving to the tertiary alcohol Methyl cadmium was used in one of the steps leading to cholesterol total synthesis 6 Another synthetic use of an organocadmium is the reaction of diisoamylcadmium with b carbomethoxypropionyl chloride to methyl 4 keto 7 methyloctanoate without reacting further with the ketone group or the ester group 7 This selectivity is observed provided that the reaction is carried out salt free 8 When the cadmium reagent is generated in situ from a cadmium salt the halide generates a more nucleophilic organocadmium reagent an ate complex The same salt effect can be observed with organozinc compounds Dimethylcadmium has been used to synthesize colloidal nanocrystals of II VI materials such as cadmium selenide Its toxic and volatile nature has led researchers to look elsewhere for cadmium precursors such as cadmium oxide 9 Toxicity EditCadmium compounds are toxic Dimethylcadmium is toxic to the kidney the liver the central nervous system and the respiratory organs when inhaled 10 Cadmium compounds in general are considered to be carcinogen to humans by the IARC 11 References Edit Synthetic Methods of Organometallic and Inorganic Chemistry Vol 5 Copper Silver Gold Zinc Cadmium and Mercury W A Herrmann Ed ISBN 3 13 103061 5 Felix Hanke Sarah Hindley Anthony C Jones Alexander Steiner 2016 The Solid State Structures of the High and Low Temperature Phases of Dimethylcadmium Chemical Communications 52 66 10144 10146 doi 10 1039 c6cc05851e PMID 27457504 Erich Krause 1917 Einfache Cadmiumdialkyle I Mitteilung uber organische Cadmium Verbindungen Berichte der deutschen chemischen Gesellschaft 50 2 1813 1822 doi 10 1002 cber 19170500292 Burton Donald J Yang Zhen Yu Morken Peter A 1994 Fluorinated organometallics Vinyl Alkynyl Allyl Benzyl Propargyl and Aryl Tetrahedron 50 10 2993 3063 doi 10 1016 S0040 4020 01 81105 4 David A Shirley 2011 The Synthesis of Ketones from Acid Halides and Organometallic Compounds of Magnesium Zinc and Cadmium Org Reactions doi 10 1002 0471264180 or008 02 Woodward R B Sondheimer Franz Taub David Heusler Karl McLamore W M 1952 The Total Synthesis of Steroids Journal of the American Chemical Society 74 17 4223 51 doi 10 1021 ja01137a001 Cason James Proutyear 1948 Franklin S Methyl 4 Keto 7 Methyloctanoate Organic Syntheses 28 75 doi 10 15227 orgsyn 028 0075 Jones Paul R Desio Peter J 1978 The less familiar reactions of organocadmium reagents Chemical Reviews 78 5 491 516 doi 10 1021 cr60315a001 Peng ZA Peng X 2001 Formation of high quality CdTe CdSe and CdS nanocrystals using CdO as precursor Journal of the American Chemical Society 123 1 183 4 doi 10 1021 ja003633m PMID 11273619 Spiridonova EIa 1991 Experimental study of toxic properties of dimethylcadmium Gigiena Truda I Professional nye Zabolevaniia in Russian 6 14 7 PMID 1916391 Cadmium and Cadmium compounds Arsenic Metals Fibres and Dusts International Agency for Research on Cancer 2012 pp 121 145 ISBN 9789283201359 Retrieved from https en wikipedia org w index php title Organocadmium chemistry amp oldid 1128261837, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.