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性質
アルシンの融点は-117°Cで、沸点は-55°Cです。常温では無色の気体として存在し、独特のにんにく臭を持っています。
0°Cの100gの水に、0.0019gのアルシンが溶解します。極性溶媒に溶けやすく、有機溶媒には溶けにくいです。酸解離定数はpKa=25です。燃焼によって、水と三酸化ヒ素 (As2O3) が生じます。光、熱、水などにより分解し、ヒ素と水素になります。
アルシンの化学的性質は、PH3やSbH3などの対応するプニクトゲン (英: pnictogen) の平均により予測可能です。アルシンには還元作用があり、酸化剤と爆発的に反応します。引火しやすいため、取り扱いには注意が必要です。硝酸銀水溶液と反応して銀が遊離し、標準酸化還元電位はEº=-0.225Vです。高濃度の硝酸銀水溶液によって、ヒ化銀を含んだ黄色の複塩であるAg3As・3AgNO3が沈殿します。
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解説
アルシン，化学式 AsH3 。水素化ヒ素またはヒ化水素ともいう。無色，中性の気体で不快なにんにく臭がある。猛毒。融点－117℃，沸点－55℃。 300℃で分解してヒ素を遊離する。また光に当ると，湿ったヒ化水素はただちに分解し，黒色の光沢あるヒ素を析出する。水に不溶。過マンガン酸カリウム溶液，臭素水に通すと分解除去することができる。点火すると青色の炎をあげて燃え，この炎を冷たい皿に触れさせるとヒ素が析出してヒ素鏡を生じる。水に対する溶解度20ml/100ml。エチルアルコールにわずか溶ける。きわめて有毒で，その毒性は一酸化炭素の10～20倍ともいわれる。取扱いはすべて性能のよいドラフトで行う必要がある。
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構造
アルシンは水素とヒ素の化合物であり、分子量は77.95です。気体での密度は4.93g/Lで、−64°Cでの液体の密度は1.640g/mLです。
アルシンの立体構造は、アンモニアに似ています。∠H–As–Hは91.8°で、3つの等価な1.519ÅのAs–H結合を持つピラミッド型の分子です。水素の結合角はアンモニアよりも小さく、直角に近いです。ヒ素の電気陰性度は2.0、水素の電気陰性度は2.1であり、アンモニアと比べて極性が弱く、水素結合を作りません。
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合成
ヒ素を含む化学物質に触媒としてを加えて、希硫酸で反応させると、アルシンを合成可能です。アルシンと水素ガスを燃焼して、その炎が冷たいガラスや磁製皿に触れると、単体のヒ素が付着し、光沢のあるヒ素鏡が得られます。
ヒ化カルシウムと希硫酸が反応しても、アルシンを生成可能です。バクテリアやカビによって、顔料のシェーレグリーン (英: Scheele's Green) が分解すると、アルシンが生じる可能性があります。
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説明
Arsine is a colorless, extremely toxic, flammable
gas at room temperature and atmospheric
pressure and is heavier than air. It has a mild
garliclike odor and acts as a blood and nerve
poison. It can be fatal if inhaled in sufficient
quantity and can form flammable mixtures with
air.
Arsine is shipped as a liquefied compressed
gas in steel cylinders under its own vapor pressure
of 219.7 psia (1515 kPa, abs). Arsine is
slightly soluble in both water and organic solvents.
It reacts readily with agents such as potassium
permanganate, bromine, and sodium
hypochlorite to form arsenic compounds. Arsine
is stable at room temperature, but begins to decompose
into its elements around 446°F to
464°F (230°C to 240°C).
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化学的特性
Arsine is a highly toxic, colorless gas with a garlic odor. It is soluble in water, benzene,
and chloroform. It is extremely flammable and explosive when exposed to heat, sparks, or
flames. Arsine decomposes on heating and under the infl uence of light and moisture, producing
toxic arsenic fumes. Arsine reacts with strong oxidants, causing explosion hazard
and may explosively decompose on shock, friction, or concussion. Workers in the metallurgical
industry involved in the production process and the maintenance of furnaces, and
in the microelectronics industry get exposed to the substance. Arsine is extensively used in
semiconductor industries, and in the manufacture of microchips.
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物理的性質
Colorless gas; garlic-like unpleasant odor; liquefies at -55°C; solidifies at -116.3°C; heavier than air; gas density 2.695 (air =1); sparingly soluble in cold water (~ 20 mg/100 g water or about 640 mg/L at the NTP); soluble in chloroform and benzene.
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使用
Arsine (AsH3), as a colorless gas, is also known as arsenic hydride. It is used to synthesize
organic compounds and as the major ingredient of several military poisons, including the
wartime gas lewisite.
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定義
A poisonous colorless gas
with an unpleasant smell. It decomposes to
arsenic and hydrogen at 230°C. It is produced
in the analysis for arsenic (Marsh’s
test).
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製造方法
Arsine is produced by the reaction of arsenic trichloride, arsenic trioxide or
any inorganic arsenic compound with zinc and sulfuric acid. It is also made by
treating a solution of sodium arsenide or potassium arsenide in liquid ammonia
with ammonium bromide:
Na3As + 3NH4Br → AsH3 + 3NaBr + 3NH3
It may be also prepared by decomposition of alkali metal arsenides by water;
or arsenides of other metals with acids:
Ca3As2 + 6 HCl → 2 AsH3 + 3 CaCl2
A poor yield may be obtained if water is substituted for acids. Thus calcium arsenide reacts with water to produce about 15% arsine.
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用途
これを利用したヒ素の検出法がマーシュの試験法である。塩素を通ずると燃え、ヒ素と塩化水素を生ずる。塩素水と反応する場合は亜ヒ酸、ヒ酸となる。アルシンには還元作用があり、硝酸銀溶液から銀を沈殿する。
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空気と水の反応
Highly flammable. On exposure to light, decomposes rapidly depositing shiny black arsenic.
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反応プロフィール
ARSINE decomposes into its elements (arsenic, gaseous hydrogen) when heated to 300°C. Can form accidentally by the reaction of arsenic impurities with mineral acids (hydrochloric acid, sulfuric acid) in the presence of common metals (iron, zinc). A reducing agent---not oxidized by air at room temperature [Kirk-Othmer, 3rd ed., Vol. 3, 1978, p. 251], but may react vigorously with other oxidizing agents [Sax, 9th ed., 1996, p. 279]. Moderately explosive in combination with chlorine or nitric acid. When heated to decomposition or ignited, ARSINE emits highly toxic fumes of metallic arsenic.
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危険性
Highly poisonous by inhalation. Periph-
eral nervous system and vacular system impairment,
kidney and liver impairment.
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健康ハザード
ARSINE is highly toxic by inhalation; a very short exposure to small quantities may cause death or permanent injury. ARSINE is the most powerful hemolytic poison encountered in industry.
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火災危険
Vapors may travel to a source of ignition and flash back. Container may explode in heat of fire. When heated to decomposition, emits highly toxic fumes. Can react vigorously with oxidizing materials. May explode when exposed to chlorine, nitric acid, or potassium plus ammonia. On exposure to light, moist ARSINE decomposes quickly, depositing shiny black arsenic.
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燃焼性と爆発性
Arsine is flammable in air, having a lower explosion limit (LEL) of 5.8%. The upper
limit has not been determined. Combustion products (arsenic trioxide and water) are
less toxic than arsine itself. In the event of an arsine fire, stop the flow of gas if
possible without risk of harmful exposure and let the fire burn itself out.
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使用用途
アルシンは、半導体の製造過程で使用されるガスの一つとして知られています。ただしアルシンは非常に毒性が強く、血液や腎臓に重大なダメージを与えます。そのため、アルシンによる半導体製造作業環境汚染が問題となっており、半導体製造環境下での最適なアルシンの定量方法の研究が重要です。
またアルシンは、熱を加えるとヒ素が生じます。この性質を利用して、微量のヒ素を検出可能です。マーシュ法 (英: Marsh test) と呼ばれ、1836年にジェームズ・マーシュ (英: James Marsh) によって創案されました。
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有機アルシン
ヒ化水素の水素原子を炭化水素やハロゲンなどで置換した化合物も、総称してアルシンと呼ばれます。一連の誘導体の一般式はRR1R2Asです。それぞれの置換基はHまたは有機基を示します。一般的に不快臭を有し、猛毒です。
具体例としてメチルアルシンが挙げられ、化学式はCH3AsH2と表されます。トリフェニルアルシン (英: Triphenylarsine) は配位子として使用可能です。化学式は(C6H5)3Asです。
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化学性质
毒性が強く，空気に触れると発火する
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材料の用途
Arsine is noncorrosive and may, therefore, be
used with most of the commercially available
metals. However, since arsine is mainly used for
the electronics industry, stainless steel is recommended
for the gas delivery systems. Stainless
steel regulators should be used for all highpurity
applications with arsine and arsine mixtures.
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安全性プロファイル
Confirmed human
carcinogen. Poison by inhalation. Human
red blood cell, gastrointestinal system,
central nervous system, and other systemic
effects by inhalation. Flammable when
exposed to flame. Moderately explosive
when exposed to Cl2, HNO3, (K + NH3,
open flame, or powerful shock. Dangerous,
more toxic than its oxidation product. When
heated to decomposition it emits highly
toxic fumes of arsenic. See also ARSENIC,
ARSENIC COMPOUNDS, and
HYDRIDES.
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職業ばく露
Arsine is used in making electronic,
semiconductor components; in organic syntheses; and in
making lead-acid storage batteries. Arsine may be generated
by side reactions or unexpectedly; e.g., it may be generated
in metal pickling operations; metal drossing
operations; or when inorganic arsenic compounds contact
sources of nascent hydrogen. It has been known to occur as
an impurity in acetylene. Most occupational exposure
occurs in chemical, smelting, and refining industries. It has
been used as a poison gas. Cases of exposure have come
from workers dealing with zinc, tin, cadmium, galvanized
coated aluminum; and silicon and steel metals. A regulated,
marked area should be established where this chemical is handled, used, or stored in compliance with OSHA
Standard 1910.1045. SA is used as a military poison gas
(blood agent). It forms cyanide in the body.
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概要
アルシン (英: Arsine) とは、化学式がAsH3で示されるヒ素の水素化合物です。
ヒ化水素 (英: Hydrogen arsenide) や水素化ヒ素 (英: Arsenic hydride) とも呼ばれます。ヒトに対して猛毒で、アルシンの許容濃度は時間加重平均濃度 (英: Time-Weighted Average) で0.005ppmです。
ヒトが大量に吸入した際には、腎臓や血液に影響が出て、最悪の場合には死に至ります。アルシンの症状は、数時間から数日後に見られる場合もあり、医学的な経過観察が必要です。
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発がん性
Arsenic has been considered a human carcinogen for a number of years(1),but the mechanisms underlying these processes have remained elusive due in part to the absence of an appropriate animal model. There
are a number of hypotheses for the mechanisms of arsenical action that include arsenical inhibition of DNA repair, cocarcinogenesis, and more recently the concept of arsenical production of ROS(65,66) that may act in concert with these mechanisms. It is clear from in vitro mutagenicity test systems that arsenicals are not direct-acting mutagens but rather act via some secondary mechanism(s). Given the long history and knowledge that arsenicals in air and water produce human cancers, this is a remarkable situation with regard to occupational and environmental exposures. Most studies of animals exposed to arsenate or arsenite by the oral route have not detected any clear evidence for an increased incidence of skin cancer or other cancers. Recently, a series of studies presented evidence that inorganic arsenic may be a transplacental carcinogen in animals. Waalkes et al. exposed timed pregnant mice to sodium arsenite in drinking water during gestation days 8–18. Dose-related increases in hepatocellular carcinomas and adrenal tumors in the male offspring and uterine hyperplasia in female offspring from treated dams were reported. The offspring also had increase in the number of malignant tumors. Aberrant estrogen signaling, potentially through inappropriate estrogen receptora, may play a role in the arsenic-induced tumors in these offspring.
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環境運命予測
Arsine acts predominantly as a hemolytic agent. Hemolysis
appears to be dependent on membrane disruption as a result
of arsine reactions with sulfhydryl groups and from formation
of hydrogen peroxide and adducts with oxyhemoglobin.
Failure of the kidneys and other organs is probably not only
due to the effects of red blood cell debris slugging within the
microcirculation but also to a direct toxic effect on the
organs.
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貯蔵
cylinders of arsine should be
stored and used in a continuously ventilated gas cabinet or fume hood. Local fire
codes should be reviewed for limitations on quantity and storage requirements.
Carbon steel, stainless steel, Monel?, and Hastelloy ?C are preferred materials for
handling arsine; brass and aluminum should be avoided. Kel-F? and Teflon? are
preferred gasket materials; Viton? and Nylon? are acceptable.
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合成方法
塩化ヒ素をエーテル中でLiAlH4により還元して合成する
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輸送方法
UN2188 Arsine, Hazard class: 2.3; Labels: 2.3-
Poisonous gas, 2.1-Flammable gas, Inhalation Hazard Zone
A. Cylinders must be transported in a secure upright position,
in a well-ventilated truck. Protect cylinder and labels
from physical damage. The owner of the compressed gas
cylinder is the only entity allowed by federal law (49CFR)
to transport and refill them. It is a violation of transportation
regulations to refill compressed gas cylinders without the
express written permission of the owner. Military driver shall
be given full and complete information regarding shipment
and conditions in case of emergency. AR 50-6 deals specifically
with the shipment of chemical agents. Shipments of
agent will be escorted in accordance with AR 740-32.
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不和合性
Arsine forms explosive mixture with air.
SA reacts with strong oxidizers, nitric acid, causing an
explosion hazard. Thermally unstable; shock, friction, and
concussion sensitive; can explosively decompose. Can
explode on contact with warm, dry air. Violent reaction
with acids, halogens, mixtures of potassium and ammonia.
Decomposes to metallic arsenic (fumes) on exposure to
light, moisture or upon decomposition from heat or
ignition.
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廃棄物の処理
Return refillable compressed
gas cylinders to supplier. Arsine may be disposed of by controlled
burning. When possible, cylinders should be sealed
and returned to suppliers. Seek guidance from regulatory
agencies as to proper disposal. Consult with environmental
regulatory agencies for guidance on acceptable disposal practices.
Generators of waste containing this contaminant
(≥100 kg/mo) must conform with EPA regulations governing
storage, transportation, treatment, and waste disposal.
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予防処置
Occupational workers should be careful during handling/use of arsine. Workers should
use protective gloves: neoprene, butyl rubber, PVC, polyethylene, or Tefl on. Workers
should also use appropriate protective equipment. If a leak occurs in a user’s equipment,
be certain to purge the piping with an inert gas prior to attempting repairs and evacuate
all personnel from the affected area. The compressed gas cylinders should not be refi lled
without the express written permission of the owner.
