Phenyldichloroarsine
Encyclopedia
Phenyldichloroarsine, NATO abbreviation PD, is an organic arsenical
vesicant and vomiting agent developed by Germany 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
.
(MD), during World War I
between 1917 and 1918. Phenyldichloroarsine and another organic arsenical, ethyldichloroarsine
were soon added to the German arsenal.
upon contact with water. The reaction with water is very slow, the substance sinks, and the reaction is considered non-hazardous. Another product of hydrolysis
is phenylarsenious acid, which is a severe irritant to the mucous membranes and skin
. Most often found in a liquid state, the chemical is an organic dithiol-arsenical. 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. An impure solution of PD also emits a characteristically unpleasant horseradish
or garlic
-like odor, which is detectable at .1 ppm.
Phenyldichloroarsine is one of four organic arsenicals, the other three are lewisite
(L), methyldichloroarsine
(MD),and ethyldichloroarsine
(ED). PD is considered an analog of lewisite. At its freezing point
, -20 °C, PD becomes a microcrystalline
solid mass. The compound has a C-metalloid bond
between the phenyl group
and the arsenic and two covalent bond
s between the arsenic and the chlorine
.
with arsenic trichloride
. Anhydrous aluminum chloride acts as a catalyst in this reaction.
agent and is classified as a vesicant or a vomiting/incapacitating agent
. It was used as a weapon during World War I, where it showed itself as less effective than other vomiting agents. The Japanese may also have used phenyldichloroarsine along with mustard agents and lewisite in China during World War II
. Phenyldichloroarsine is an arsenical vesicant which is most often mixed with other mustard agents for use in chemical warfare. This does not increase the severity of its effects but does tend to confuse exposure diagnosis.
PD was developed for use in wet environments, because of its tendency to persist in cool and shaded areas. Phenyldichloroarsine can have a persistence lasting anywhere from 2 to 7 days under usual environmental conditions. 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. Phenyldichloroarsine has also been used by banks and other high-security facilities to defend against security breaches.
, extensive bone marrow
damage can also result. 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. The blistering resultant from PD exposure may also be delayed, for as little as 30 minutes, or as long as 32 hours depending upon the concentration of the dose.
The molecular toxicology of PD is not well understood, 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 .
Arsenical
An arsenical is a arsenic-containing compound.Examples include:* arsanilic acid* arsenamide* arsenates* arsenites* arsphenamine* p-azobenzenearsonate* cacodylic acid* melarsoprol* roxarsone...
vesicant and vomiting agent developed by Germany for use as a chemical warfare
Chemical warfare
Chemical warfare involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from Nuclear warfare and Biological warfare, which together make up NBC, the military acronym for Nuclear, Biological, and Chemical...
agent during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. The agent is known by multiple synonyms and is technically classified as a vesicant, or blister agent
Blister agent
A blister agent, or vesicant, is a chemical compound that causes severe skin, eye and mucosal pain and irritation. They are named for their ability to cause severe chemical burns, resulting in painful water blisters on the bodies of those affected...
.
History
German chemists weaponized the first organic arsenical, methyldichloroarsineMethyldichloroarsine
Methyldichloroarsine, sometimes abbreviated "MD", is an organoarsenic compound with the formula CH3AsCl2. This colourless volatile liquid is a highly toxic vesicant that has been used in chemical warfare.-History:...
(MD), during World War I
Poison gas in World War I
The use of chemical weapons in World War I ranged from disabling chemicals, such as tear gas and the severe mustard gas, to lethal agents like phosgene and chlorine. This chemical warfare was a major component of the first global war and first total war of the 20th century. The killing capacity of...
between 1917 and 1918. Phenyldichloroarsine and another organic arsenical, ethyldichloroarsine
Ethyldichloroarsine
Ethyldichloroarsine, sometimes abbreviated "ED", is an organoarsenic compound with the formula CH3CH2AsCl2. This colourless volatile liquid is a highly toxic vesicant or blister agent that was used in chemical warfare. The molecule is pyramidal with the Cl-As-Cl and C-As-Cl angles approaching 90°...
were soon added to the German arsenal.
General
Phenyldichloroarsine is an odorless, colorless substance that can form hydrochloric acidHydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
upon contact with water. The reaction with water is very slow, the substance sinks, and the reaction is considered non-hazardous. Another product of hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
is phenylarsenious acid, which is a severe irritant to the mucous membranes and skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
. Most often found in a liquid state, the chemical is an organic dithiol-arsenical. 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. An impure solution of PD also emits a characteristically unpleasant horseradish
Horseradish
Horseradish is a perennial plant of the Brassicaceae family, which also includes mustard, wasabi, broccoli, and cabbages. The plant is probably native to south eastern Europe and the Arab World , but is popular around the world today...
or garlic
Garlic
Allium sativum, commonly known as garlic, is a species in the onion genus, Allium. Its close relatives include the onion, shallot, leek, chive, and rakkyo. Dating back over 6,000 years, garlic is native to central Asia, and has long been a staple in the Mediterranean region, as well as a frequent...
-like odor, which is detectable at .1 ppm.
Phenyldichloroarsine is one of four organic arsenicals, the other three are lewisite
Lewisite
Lewisite is an organoarsenic compound, specifically an arsine. It was once manufactured in the U.S. and Japan as a chemical weapon, acting as a vesicant and lung irritant...
(L), methyldichloroarsine
Methyldichloroarsine
Methyldichloroarsine, sometimes abbreviated "MD", is an organoarsenic compound with the formula CH3AsCl2. This colourless volatile liquid is a highly toxic vesicant that has been used in chemical warfare.-History:...
(MD),and ethyldichloroarsine
Ethyldichloroarsine
Ethyldichloroarsine, sometimes abbreviated "ED", is an organoarsenic compound with the formula CH3CH2AsCl2. This colourless volatile liquid is a highly toxic vesicant or blister agent that was used in chemical warfare. The molecule is pyramidal with the Cl-As-Cl and C-As-Cl angles approaching 90°...
(ED). PD is considered an analog of lewisite. At its freezing point
Freezing Point
Freezing Point is a news journal in the People's Republic of China which has been the subject of controversy over its criticism of Communist Party officials and the sympathetic ear it lent to a Chinese historian who had criticized official history textbooks...
, -20 °C, PD becomes a microcrystalline
Microcrystalline
A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination.-See also:* Macrocrystalline* Microcrystalline silicon* Protocrystalline* Rock microstructure...
solid mass. The compound has a C-metalloid bond
Metallic bond
Metallic bonding is the electrostatic attractive forces between the delocalized electrons, called conduction electrons, gathered in an "electron sea", and the positively charged metal ions...
between the phenyl group
Phenyl group
In organic chemistry, the phenyl group or phenyl ring is a cyclic group of atoms with the formula C6H5. Phenyl groups are closely related to benzene. Phenyl groups have six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the...
and the arsenic and two covalent bond
Covalent bond
A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding....
s between the arsenic and the chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
.
Synthesis
Phenyldichloroarsine is produced by reacting benzeneBenzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
with arsenic trichloride
Arsenic trichloride
Arsenic trichloride is an inorganic compound with the formula AsCl3, also known as arsenous chloride or butter of arsenic. This poisonous oil is colourless, although impure samples may appear yellow. It is an intermediate in the manufacture of organoarsenic compounds.-Structure:AsCl3 is a...
. Anhydrous aluminum chloride acts as a catalyst in this reaction.
Uses
Phenyldichloroarsine is useful as a chemical warfareChemical warfare
Chemical warfare involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from Nuclear warfare and Biological warfare, which together make up NBC, the military acronym for Nuclear, Biological, and Chemical...
agent and is classified as a vesicant or a vomiting/incapacitating agent
Incapacitating agent
The term incapacitating agent is defined by the U.S. Department of Defense asLethal agents are primarily intended to kill, but incapacitating agents can also kill if administered in a potent enough dose, or in certain scenarios....
. It was used as a weapon during World War I, where it showed itself as less effective than other vomiting agents. The Japanese may also have used phenyldichloroarsine along with mustard agents and lewisite in China during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. Phenyldichloroarsine is an arsenical vesicant which is most often mixed with other mustard agents for use in chemical warfare. This does not increase the severity of its effects but does tend to confuse exposure diagnosis.
PD was developed for use in wet environments, because of its tendency to persist in cool and shaded areas. Phenyldichloroarsine can have a persistence lasting anywhere from 2 to 7 days under usual environmental conditions. 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. Phenyldichloroarsine has also been used by banks and other high-security facilities to defend against security breaches.
Biological effects
PD damages the eyes, lungs, throat and nasal membranes. PD immediately affects the eyes and blindness can result, though it requires high doses. It also induces nausea and vomiting, an inhalation of as little as 5-50 milligrams can induce severe vomiting. Long-term exposure to PD can cause systemic damage by replacing calcium with arsenicArsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
, extensive bone marrow
Bone marrow
Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...
damage can also result. 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. The blistering resultant from PD exposure may also be delayed, for as little as 30 minutes, or as long as 32 hours depending upon the concentration of the dose.
The molecular toxicology of PD is not well understood, 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
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...
membrane and interacted with something inside the cell. The study also found that hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
was not responsible for "holding" the PD in its bond with the erythrocytes (red blood cells), instead glutathione
Glutathione
Glutathione is a tripeptide that contains an unusual peptide linkage between the amine group of cysteine and the carboxyl group of the glutamate side-chain...
was found to be a more likely interacting with PD inside the cell .