Cacodylic acid is an organoarsenic compound with the formula (CH3)2AsO2H. With the formula R2As(O)OH, it is the simplest of the arsinic acids. It is a colorless solid that is soluble in water.
Neutralization of cacodylic acid with base gives cacodylate salts, e.g. sodium cacodylate. They are potent herbicides. Cacodylic acid/sodium cacodylate is a buffering agent in the preparation and fixation of biological samples for electron microscopy and in protein crystallography.
"The smell of this body produces instantaneous tingling of the hands and feet, and even giddiness and insensibility... It is remarkable that when one is exposed to the smell of these compounds the tongue becomes covered with a black coating, even when no further evil effects are noticeable".
His work in this field led to an increased understanding of the methyl group.
Cacodyl oxide, ((CH3)2As)2O, is often considered the first organometallic compound to be prepared synthetically.
Cacodylic acid and its salts were incorporated into herbicides by a large variety of manufacturers under numerous brand names. APC Holdings Corp. sold cacodylic acid and its salts under the Phytar brand name.[4] The variety Phytar 560G, a mixture of cacodylic acid and sodium cacodylate, was used during the Vietnam War as a defoliant under the name "Agent Blue".[5]
Reactionsedit
Cacodylic acid is a weak acid with a pKa of around 6.25.[6]
Cacodylic acid can be reduced to dimethylarsine , which is a versatile intermediate for the synthesis of other organoarsenic compounds:[7][8]
Cacodylic acid is highly toxic by ingestion, inhalation, or skin contact. The U.S. EPA states that all forms of arsenic are a serious risk to human health and the United States Agency for Toxic Substances and Disease Registry ranked arsenic as number 1 in its 2001 Priority List of Hazardous Substances at Superfund sites.[9] Arsenic is classified as a Group-A carcinogen.[9]
^ abBetz, R.; McCleland, C.; Marchand, H. (2011). "The monoclinic polymorph of dimethylarsinic acid". Acta Crystallogr. E. 67 (8): m1013. doi:10.1107/S1600536811025505. PMC3212109. PMID 22090811.
^Trotter, J.; Zobel, T. (1965). "826. Stereochemistry of arsenic. Part XVI. Cacodylic acid". J. Chem. Soc.: 4466–4471. doi:10.1039/JR9650004466.
^Stanley A. Greene (2005). Sittig's Handbook of Pesticides and Agricultural Chemicals. William Andrew. p. 132. ISBN978-0-8155-1903-4.
^Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides; Institute of Medicine (1994). Veterans and Agent Orange: Health Effects of Herbicides Used in Vietnam. National Academies Press. pp. 89–90. ISBN978-0-309-55619-4.
^Shin, T.-W., Kim, K., Lee, I.-J. (April 1997). "Spectrophotometric determination of the acid dissociation constants for cacodylic acid and p-Nitrophenol at elevated temperatures". Journal of Solution Chemistry. 26 (4): 379–390. doi:10.1007/BF02767677. ISSN 0095-9782.
^Feltham, R. D.; Kasenally, A.; Nyholm, R. S. (1967). "A New Synthesis of Di- and Tri-Tertiary Arsines". Journal of Organometallic Chemistry. 7 (2): 285–288. doi:10.1016/S0022-328X(00)91079-9.
^Burrows, G. J. and Turner, E. E., "A New Type of Compound containing Arsenic", Journal of the Chemical Society Transactions, 1920, 1374-1383
^ abDibyendu, Sarkar; Datta, Rupali (2007). . EPA. United States Environmental Protection Agency. Archived from the original on 17 March 2020. Retrieved 25 February 2018.
Further readingedit
Kenyon, E. M.; Hughes, M. F. (2001). "A Concise Review of the Toxicity and Carcinogenicity of Dimethylarsenic Acid". Toxicology. 160 (1–3): 227–236. doi:10.1016/S0300-483X(00)00458-3. PMID 11246143.
Elschenbroich, C; Salzer, A. (1992) Organometallics, 2nd Edition
External linksedit
Case Studies in Environmental Medicine - Arsenic Toxicity
Bunsen Biography
April 08, 2024
cacodylic, acid, organoarsenic, compound, with, formula, 2aso2h, with, formula, r2as, simplest, arsinic, acids, colorless, solid, that, soluble, water, ball, stick, model, namespreferred, iupac, name, dimethylarsinic, acidother, names, dimethylarsenic, acid, h. Cacodylic acid is an organoarsenic compound with the formula CH3 2AsO2H With the formula R2As O OH it is the simplest of the arsinic acids It is a colorless solid that is soluble in water Cacodylic acid Ball and stick model 1 2 NamesPreferred IUPAC name Dimethylarsinic acidOther names Dimethylarsenic acid Cacodylic acid Hydroxydimethylarsine oxide Arsecodile Ansar Silvisar Phytar 560 DMAA UN 1572IdentifiersCAS Number 75 60 5 Y3D model JSmol Interactive imageBeilstein Reference 1736965ChEBI CHEBI 29839 NChEMBL ChEMBL1231644ChemSpider 2418 YDrugBank DB02994 YECHA InfoCard 100 000 804EC Number 200 883 4Gmelin Reference 130562KEGG C07308 YPubChem CID 2513RTECS number CH7525000UNII AJ2HL7EU8K YUN number 1572CompTox Dashboard EPA DTXSID7020508InChI InChI 1S C2H7AsO2 c1 3 2 4 5 h1 2H3 H 4 5 YKey OGGXGZAMXPVRFZ UHFFFAOYSA N YInChI 1 C2H7AsO2 c1 3 2 4 5 h1 2H3 H 4 5 Key OGGXGZAMXPVRFZ UHFFFAOYAPSMILES O As O C CPropertiesChemical formula C2H7AsO2Molar mass 137 9977 g molAppearance White crystals or powderOdor odorlessDensity gt 1 1 g cm3Melting point 192 to 198 C 378 to 388 F 465 to 471 K Boiling point gt 200 C 392 F 473 K Solubility in water 66 7 g 100 mlSolubility soluble in ethanol acetic acid insoluble in diethyl etherAcidity pKa 6Magnetic susceptibility x 79 9 10 6 cm3 molStructureCrystal structure triclinic 3 monoclinic 2 HazardsGHS labelling PictogramsSignal word DangerHazard statements H301 H331 H410Precautionary statements P261 P264 P270 P271 P273 P301 P310 P304 P340 P311 P321 P330 P391 P403 P233 P405 P501NFPA 704 fire diamond 400Lethal dose or concentration LD LC LD50 median dose 23 100 mg kg rat and mouse oral Safety data sheet SDS External MSDSExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Neutralization of cacodylic acid with base gives cacodylate salts e g sodium cacodylate They are potent herbicides Cacodylic acid sodium cacodylate is a buffering agent in the preparation and fixation of biological samples for electron microscopy and in protein crystallography Contents 1 History 2 Reactions 3 Health effects 4 See also 5 References 6 Further reading 7 External linksHistory editIn the 18th century it was found that combining As2O3 and four equivalents of potassium acetate CH3CO2K gives a product called Cadet s fuming liquid which contains cacodyl oxide CH3 2As 2O and cacodyl CH3 2As 2 Early research into cacodyls was reported by Robert Bunsen at the University of Marburg Bunsen said of the compounds The smell of this body produces instantaneous tingling of the hands and feet and even giddiness and insensibility It is remarkable that when one is exposed to the smell of these compounds the tongue becomes covered with a black coating even when no further evil effects are noticeable His work in this field led to an increased understanding of the methyl group Cacodyl oxide CH3 2As 2O is often considered the first organometallic compound to be prepared synthetically Cacodylic acid and its salts were incorporated into herbicides by a large variety of manufacturers under numerous brand names APC Holdings Corp sold cacodylic acid and its salts under the Phytar brand name 4 The variety Phytar 560G a mixture of cacodylic acid and sodium cacodylate was used during the Vietnam War as a defoliant under the name Agent Blue 5 Reactions editCacodylic acid is a weak acid with a pKa of around 6 25 6 Cacodylic acid can be reduced to dimethylarsine which is a versatile intermediate for the synthesis of other organoarsenic compounds 7 8 CH3 2AsO2H 2 Zn 4 HCl CH3 2AsH 2 ZnCl2 2 H2O CH3 2AsO2H SO2 HI CH3 2AsI SO3 H2OHealth effects editCacodylic acid is highly toxic by ingestion inhalation or skin contact The U S EPA states that all forms of arsenic are a serious risk to human health and the United States Agency for Toxic Substances and Disease Registry ranked arsenic as number 1 in its 2001 Priority List of Hazardous Substances at Superfund sites 9 Arsenic is classified as a Group A carcinogen 9 See also editArsenic ArsineReferences edit Betz R McCleland C Marchand H 2011 CSD Entry CADYLA01 Dimethylarsinic acid Cambridge Structural Database Access Structures Cambridge Crystallographic Data Centre doi 10 5517 ccx73mv Retrieved 2021 12 21 a b Betz R McCleland C Marchand H 2011 The monoclinic polymorph of dimethylarsinic acid Acta Crystallogr E 67 8 m1013 doi 10 1107 S1600536811025505 PMC 3212109 PMID 22090811 Trotter J Zobel T 1965 826 Stereochemistry of arsenic Part XVI Cacodylic acid J Chem Soc 4466 4471 doi 10 1039 JR9650004466 Stanley A Greene 2005 Sittig s Handbook of Pesticides and Agricultural Chemicals William Andrew p 132 ISBN 978 0 8155 1903 4 Committee to Review the Health Effects in Vietnam Veterans of Exposure to Herbicides Institute of Medicine 1994 Veterans and Agent Orange Health Effects of Herbicides Used in Vietnam National Academies Press pp 89 90 ISBN 978 0 309 55619 4 Shin T W Kim K Lee I J April 1997 Spectrophotometric determination of the acid dissociation constants for cacodylic acid and p Nitrophenol at elevated temperatures Journal of Solution Chemistry 26 4 379 390 doi 10 1007 BF02767677 ISSN 0095 9782 Feltham R D Kasenally A Nyholm R S 1967 A New Synthesis of Di and Tri Tertiary Arsines Journal of Organometallic Chemistry 7 2 285 288 doi 10 1016 S0022 328X 00 91079 9 Burrows G J and Turner E E A New Type of Compound containing Arsenic Journal of the Chemical Society Transactions 1920 1374 1383 a b Dibyendu Sarkar Datta Rupali 2007 Biogeochemistry of Arsenic in Contaminated Soils of Superfund Sites EPA United States Environmental Protection Agency Archived from the original on 17 March 2020 Retrieved 25 February 2018 Further reading editKenyon E M Hughes M F 2001 A Concise Review of the Toxicity and Carcinogenicity of Dimethylarsenic Acid Toxicology 160 1 3 227 236 doi 10 1016 S0300 483X 00 00458 3 PMID 11246143 Elschenbroich C Salzer A 1992 Organometallics 2nd EditionExternal links editCase Studies in Environmental Medicine Arsenic Toxicity Bunsen Biography Retrieved from https en wikipedia org w index php title Cacodylic acid amp oldid 1215464898, wikipedia, wiki, book, books, library,
