每周分子 | Molecule of the Week

Original ACS 美国化学会 ACS美国化学会 2022-07-01

收录于合集 #每周分子 110个

每周分子：苯甲酸

Molecule of the Week: Benzoic acid

苯甲酸是最简单的苯基羧酸，早在16世纪就为人所知。它的发现者之一是传说中的预言家诺查丹玛斯。苯甲酸最常见的天然来源是安息香胶，一种在安息香树的树皮中发现的树脂。

当今大多数苯甲酸是通过合成制得的。苯甲酸的第一个工业合成是将三氯甲苯水解成苯甲酸钙，然后酸化。该方法已经完全被甲苯空气氧化法所取代，避免了氯化副产物污染产品的问题。

许多加工食品中含有苯甲酸或其一种盐作为防腐剂。酸能够抑制细菌、霉菌和酵母的生长;当食物的pH值是酸性时，它的效果最好。苯甲酸也经常出现在局部抗真菌制剂中。

为什么苯甲酸是我们12月的假日分子呢? 因为苯甲酸是一种白色物质，主要用来仿制雪球中的雪花。在假期，您可能想用Steve Spangler Science或Science with Mrs. Pittenger网站介绍的方法来制作自己的雪球。

苯甲酸信息速览

CAS 登记号	65-85-0
SciFinder命名	Benzoic acid
分子式	C₇H₆O₂
摩尔质量	122.12 g/mol
外观	白色晶体
熔点	122 ºC (3.33 kPa)
水溶性	3.4 g/L

苯甲酸危害信息

GHS*分类：皮肤腐蚀/刺激，分类2
H315-导致皮肤刺激
GHS分类：严重眼睛损伤/眼睛刺激，分类1
H318-导致严重眼睛损伤
GHS分类：特定靶器官毒性(肺)，重复暴露，分类1
H372-长时间或反复暴露导致器官(肺)损伤
GHS分类：对水生环境有害，急性危害，分类3
H402-对水生生物有害

【关于每周分子】

自2001年以来，“每周分子”已成为广受欢迎的栏目。多数分子由读者推荐。每个结构都经由科学家审查，并以3-D和平面图像的形式显示，同时附有该分子简介。可以通过美国化学文摘社 (CAS) 提供的SciFinder中的CAS REGISTRY获取“每周分子”的更多信息。CAS REGISTRY中的每条物质信息都展示了物质的CAS登记号、索引名、通用名、商品名、书目信息等其他更多信息。发送邮件至motw@acs.org推荐您感兴趣的分子吧。

Benzoic acid, the simplest benzene-based carboxylic acid, has been known since the 16th century. One of its discoverers was the legendary clairvoyant Nostradamus. Its most common natural source is gum benzoin, a resin found in the bark of trees of the genus Styrax.

Most benzoic acid produced today is synthetic. Its first industrial synthesis was the hydrolysis of benzotrichloride to calcium benzoate, followed by acidification. This method has been completely displaced by the air oxidation of toluene, which avoids the problem of product contamination with chlorinated byproducts.

Many processed foods contain benzoic acid or one of its salts as a preservative. The acid inhibits the growth of bacteria, molds, and yeasts; it works best when the food has an acidic pH value. Benzoic acid also is often found in topical antifungal preparations.

Why is benzoic acid our December holiday molecule? It’s the white stuff predominantly used to mimic snowflakes in snow globes. For a holiday project, you might want to create your own snow globe by using the procedures developed by Steve Spangler Science or Science with Mrs. Pittenger.

Benzoic acidfast facts

CAS Reg. No.	65-85-0
SciFinder nomenclature	Benzoic acid
Empirical formula	C₇H₆O₂
Molar mass	122.12 g/mol
Appearance	White crystals
Melting point	122 ºC (3.33 kPa)
Water solubility	3.4 g/L

Squalene hazard information

Hazard class: Skin corrosion/irritation, category 2
H315 - Causes skin irritation
Hazard class: Serious eye damage/eye irritation, category 1
H318 - Causes serious eye damage
Hazard class: Specific target organ toxicity (lungs), repeated exposure, category 1
H372 - Causes damage to organs (lungs) through prolonged or repeated exposure
Hazard class: Hazardous to the aquatic environment, acute hazard, category 3
H304 - Harmful to aquatic life

About Molecule of the Week

MOTW has been a popular feature on ACS website since 2001. Many molecules are suggested by our website visitors. Every structure is reviewed by a scientist and displayed in 3-D and flat images with a brief description. Each week’s molecule also links to a sample record from the CAS REGISTRY, which is searched using SciFinder. Each record displays the registry number, index name and synonyms, bibliographic information, and more. Send us a molecule suggestion at motw@acs.org.

往期精选：

每周分子Molecule of the Week：角鲨烯

每周分子Molecule of the Week：1H-1,2,3-三唑

每周分子Molecule of the Week：尿酸

每周分子Molecule of the Week：2-乙酰基呋喃、2-乙酰基吡咯

每周分子Molecule of the Week：硼烷-四氢呋喃

每周分子Molecule of the Week：硬脂酸钠

每周分子Molecule of the Week：4-甲氧基苯乙烯

每周分子Molecule of the Week：硫化锌

每周分子Molecule of the Week：螺旋内酯甾酮

每周分子Molecule of the Week：白磷

每周分子Molecule of the Week：紫杉醇