Jump to content


From Wikipedia, the free encyclopedia
Skeletal formula of phenyldichloroarsine
Ball-and-stick model of the phenyldichloroarsine molecule
Preferred IUPAC name
Phenylarsonous dichloride
Other names
3D model (JSmol)
Abbreviations PD (NATO)
ECHA InfoCard 100.010.721 Edit this at Wikidata
EC Number
  • 211-791-9
RTECS number
  • CH5425000
  • InChI=1S/C6H5AsCl2/c8-7(9)6-4-2-1-3-5-6/h1-5H checkY
  • Cl[As](Cl)c1ccccc1
Molar mass 222.9315 g/mol
Appearance Colorless liquid
Density 1.65 g/cm3 (at 20 °C)
Melting point −20 °C (−4 °F; 253 K)
Boiling point 252 to 255 °C (486 to 491 °F; 525 to 528 K)
Solubility acetone, ether, benzene
log P 3.060
Vapor pressure 0.033
3.00E-05 atm·m3/mole
Atmospheric OH rate constant
1.95E-12 cm3/molecule·s
Occupational safety and health (OHS/OSH):
Main hazards
Flammability, incapacitation, blistering
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
Flash point 16 °C (61 °F; 289 K)
Lethal dose or concentration (LD, LC):
2,500 mg·min/m3
NIOSH (US health exposure limits):
PEL (Permissible)
0.5 mg/m2
Safety data sheet (SDS) New Jersey MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Phenyldichloroarsine, also known by its wartime name phenyl Dick[1] and its NATO abbreviation PD, is an organic arsenical vesicant and vomiting agent developed by Germany and France for use as a chemical warfare agent during World War I. The agent is known by multiple synonyms and is technically classified as a vesicant, or blister agent.


PD was prepared during 1917–18 in Germany and France, during World War II it was prepared in Germany.

Chemical characteristics[edit]


Phenyldichloroarsine is an odorless, colorless substance that can form hydrochloric acid upon contact with water.[2] The reaction with water is very slow, the substance sinks, and the reaction is considered non-hazardous.[3] Another product of hydrolysis is phenylarsenious acid, which is a severe irritant to the mucous membranes and skin.[2] In an impure state, phenyldichloroarsine may have a slight brown color, in its purest form though there is no color and the substance has an oily texture.[4] An impure solution of PD also emits a characteristically unpleasant horseradish or garlic-like odor, which is detectable at 0.1 ppm.[5]

Phenyldichloroarsine is one of four organic arsenicals, the other three are lewisite (L), methyldichloroarsine (MD), and ethyldichloroarsine (ED).[6] PD is considered an analog of lewisite.[7] At its freezing point, -20 °C, PD becomes a microcrystalline solid mass.[8] The compound has a C-metalloid bond between the phenyl group and the arsenic and two covalent bonds between the arsenic and the chlorine.[9]


Phenyldichloroarsine is produced by reacting benzene with arsenic trichloride. Anhydrous aluminum chloride acts as a catalyst in this reaction.[4]


Phenyldichloroarsine is an obsolete chemical warfare agent and is classified as a vesicant or a vomiting/incapacitating agent.[10] It was used as a weapon during World War I, where it showed itself as less effective than other vomiting agents.[10] Phenyldichloroarsine is an arsenical vesicant which can be mixed with mustard agents for use in chemical warfare.[11] PD was developed for use in wet environments, because of its tendency to persist in cool and shaded areas.[12] Phenyldichloroarsine can have a persistence lasting anywhere from 2 to 7 days under usual environmental conditions.[4] In open areas, it is more useful as a vomiting agent but in closed-in areas, such as basements, trenches and caves, it is highly effective because of its "extreme" vapor density.[12] Phenyldichloroarsine has also been used by banks and other high-security facilities to defend against security breaches.[4]

Biological effects[edit]

PD damages the eyes, lungs, throat and nasal membranes.[12] PD immediately affects the eyes and blindness can result, though it requires high doses.[4] It also induces nausea and vomiting, an inhalation of as little as 5-50 milligrams can induce severe vomiting.[4] Long-term exposure to PD can cause systemic damage by replacing calcium with arsenic, extensive bone marrow damage can also result.[12] Due to PD being easily recognized in the field and a relatively fast rate for decontamination procedures to become effective, the chemical is not as useful as other blister agents.[4] The blistering resultant from PD exposure may also be delayed, for as little as 30 minutes,[7] or as long as 32 hours depending upon the concentration of the dose.[4]

The molecular toxicology of PD is not well understood,[7] but a 1986 U.S. Army-sponsored report did shed some light on that area. The Army report showed that PD penetrated the red blood cell membrane and interacted with something inside the cell. The study also found that hemoglobin was not responsible for "holding" the PD in its bond with the erythrocytes (red blood cells), instead glutathione was found to be a more likely interacting with PD inside the cell .[7][12]

See also[edit]


  1. ^ Wood JR (May 1944). "Chemical Warfare-A Chemical and Toxicological Review". American Journal of Public Health and the Nation's Health. 34 (5): 455–60. doi:10.2105/AJPH.34.5.455. PMC 1625133. PMID 18015982.
  2. ^ a b Leikin JB, McFee RB (2007). Handbook of Nuclear, Biological, and Chemical Agent Exposures. Informa Health Care. pp. 356–57. ISBN 978-1420044775.)
  3. ^ Pohanish RP (2005). HazMat Data. Wiley-IEEE. pp. 895–96. ISBN 0471726109.)
  4. ^ a b c d e f g h Ledgard J (2006). A Laboratory History of Chemical Warfare Agents. Lulu.com. pp. 127–29. ISBN 1411694325.
  5. ^ Ellison HD (2007). Handbook of Chemical and Biological Warfare Agents. CRC Press. p. 156. ISBN 978-0849314346.
  6. ^ Fitzgerald GM, Vollmer T (19 June 2006). "CBRNE - Vesicants, Organic Arsenicals: L, ED, MD, PD, HL". emedicine. WebMD. Retrieved December 22, 2008.
  7. ^ a b c d O'Connor RJ, McGown EL, Dill K (August 1986). "Interaction of Phenyldicholoroarsine with Biological Molecules" (PDF). Department of Chemistry - Clemson University for U.S. Army, Letterman Army Institute of Research. Archived (PDF) from the original on May 22, 2011. Retrieved 22 December 2008.
  8. ^ Hills T (2007). The Illustrated Dictionary of Organic Chemistry. Tokyo: Lotus Press. p. 149. ISBN 978-8189093518.
  9. ^ Manahan SE (1999). Industrial Ecology: Environmental Chemistry and Hazardous Waste. CRC Press. p. 189. ISBN 1566703816.
  10. ^ a b Cashman JR (2008). Emergency Response Handbook for Chemical and Biological Agents and Weapons. CRC Press. pp. 215–19. ISBN 978-1420052657.
  11. ^ Dire DJ (21 December 2007). "CBRNE - Vesicants, Mustard: Hd, Hn1-3, H]". emedicine. WebMD. Retrieved 22 December 2008.
  12. ^ a b c d e Byrnes ME, King DA, Tierno Jr PM (2003). Nuclear, Chemical, and Biological Terrorism: Emergency Response and Public Protection. CRC Press. p. 57. ISBN 1566706513.