三氧化硫 - CAS号 7446-11-9

物化性质

熔点：

16.8 °C(lit.)
沸点：

44.8 °C
密度：

1.97 g/mL at 25 °C(lit.)
蒸气密度：

2.8 (vs air)
溶解度：

与H2O反应
介电常数：

3.1（18℃）
物理描述：

Sulfur trioxide, is a colorless to white crystalline solid which will fume in air. Often shipped with inhibitor to prevent polymerization. It reacts violently with water to form sulfuric acid with the release of heat. It is corrosive to metals and tissue. It causes eye and skin burns. Ingestion causes severe burns of mouth esophagus and stomach. The vapor is very toxic by inhalation. It is a fire risk when in contact with organic materials such as wood, cotton, fiberboard, etc.
颜色/状态：

White needles
蒸汽密度：

2.76 (EPA, 1998) (Relative to Air)
蒸汽压力：

263 mm Hg at 25 °C (est)
稳定性/保质期：

如果按照规定使用和储存，则不会发生分解。
分解：

When heated to decomposition ... emits toxic fumes of /sulfur oxides/.
腐蚀性：

Absolute dry sulfur trioxide is not corrosive to metals
汽化热：

43.14 kJ/mol at 25 °C
聚合：

Explosive polymerization in case of non-presence of stabilizer and presence of humidity.

计算性质

辛醇/水分配系数(LogP)：

-0.5
重原子数：

4
可旋转键数：

0
环数：

0.0
sp3杂化的碳原子比例：

0.0
拓扑面积：

52.2
氢给体数：

0
氢受体数：

3

ADMET

代谢

硫酸盐氧化和三氧化硫自由基形成在从健康年轻人、老年人、百岁老人捐献者以及唐氏综合症患者中分离出的多形核白细胞（PMNs）中进行研究。硫自由基形成与亚硫酸氧化酶的活性以及PMNs将亚硫酸氧化为硫酸盐的速率相关。研究了静息状态下和用佛波醇肉豆蔻酸酯（PMA）刺激的新鲜分离细胞中亚硫酸的代谢。通过使用自旋捕捉剂5,5-二甲基-1-吡咯烷-1-氧化物（DMPO）并随后形成加合物来展示三氧化硫自由基形成的速率。在亚硫酸氧化酶活性低的细胞中，加合物形成的强度最强烈，而在亚硫酸氧化酶活性高的细胞中，主要观察到加合物和DMPO羟基自由基的混合物。此外，对纯化的亚硫酸氧化酶进行的实验表明，在亚硫酸存在的情况下，酶也可以产生DMPO-OH加合物。从健康年轻人和老年人捐献者中分离出的细胞中亚硫酸氧化酶活性与三氧化硫自由基形成速率和亚硫酸氧化为硫酸盐的速率呈正相关。然而，从百岁老人和唐氏综合症患者中分离出的细胞中亚硫酸氧化酶活性似乎部分失去了将亚硫酸氧化为硫酸盐的速率。在上述两个群体中，硫中心自由基加合物的强度增加，观察到的自由基主要是三氧化硫自由基。

Sulfite oxidation and sulfur trioxide radical formation were studied in polymorphonuclear leukocytes (PMNs) isolated from healthy young, old and centenarian donors and from patients with Down's syndrome. The sulfur radical formation ... was correlated with the activity of sulfite oxidase and with the rate of sulfite oxidation to sulfate by PMNs. Sulfite metabolism was studied both in resting, and phorbol myristate acetate (PMA) stimulated freshly isolated cells. The rate of sulfur trioxide radical formation was demonstrated by use of the spin trapping agent 5,5-dimethyl-1-pyroline-1-oxide (DMPO) with subsequent formation of an adduct. The intensity of adduct formation was most intense in cells with low sulfite oxidase activity, while a mixture of the adduct and of DMPO hydroxyl radical was mainly observed in cells with high sulfite oxidase activity. Furthermore, experiments carried out on purified sulfite oxidase showed that in the presence of sulfite the enzyme could also give rise to a DMPO-OH adduct. Sulfite oxidase activity in cells isolated from healthy young and old donors was positive correlated with both rates of sulfur trioxide radical formation and sulfite oxidation to sulfate, respectively. However, sulfite oxidase activity in cells isolated from centenarians and patients with Down's syndrome seems to lose partly its rate of oxidising sulfite to sulfate. The intensity of the sulfur centered radical adduct increased in the two latter groups of population and the radical observed was predominantly sulfur trioxide radical.

来源:Hazardous Substances Data Bank (HSDB)

毒理性

暴露途径

该物质可以通过吸入其蒸汽和摄入进入人体。

The substance can be absorbed into the body by inhalation of its vapour and by ingestion.