章节大纲

  • Red race car taking a sharp turn on a winding road surrounded by trees.

    Start your engines!
    ::启动引擎!

    Race car drivers are always looking for that “edge” that will make them go faster (legally) than their competitors. One way to get more speed is to burn the gasoline in the car engine more efficiently. Methyl-t-butyl ether (MTBE) has been used for this purpose, but is being discontinued due to concerns about contamination of drinking water by leaking fuel tanks that contained this .
    ::赛车司机总是在寻找能使他们比竞争对手更快(合法)的“前沿 ” 。 加快速度的一个方法是提高汽车发动机汽油燃烧效率。 甲基丁基醚(MTBE ) 已经用于这一目的,但由于对饮用水污染的担忧而停止使用。

    Ethers
    ::以量

    An ether is an organic compound in which two groups are bonded to the same of oxygen. An ether is represented by the general formula R−O−R’. The R’ in the formula means that the hydrocarbon group can be the same as R or it can be different. The steps for naming ethers are listed below.
    ::乙醚是一种有机化合物,其中两组同氧结合在一起。一种乙醚以一般公式R-O-R ' 表示。该公式中的R表示碳氢化合物组可能与R相同,也可能不同。以下列出了命名醚的步骤。

    1. The parent compound is given by the word ether , which appears at the end of the name.
      ::母化合物由名字结尾处出现的醚字给定。
    2. The names of each alkyl group come before the word ether. If the two alkyl groups are the same, the prefix – di is used. If the two alkyl groups are different, they are listed in alphabetical order.
      ::每个烷基组的名称都出现在单词醚之前。如果两个烷基组相同,则使用前缀 - di。如果两个烷基组不同,则按字母顺序排列。
    3. Spaces are left between the names of the alkyl groups (if different) and before the word ether .
      ::在烷基组的名称(如果不同)和醚一词之前,留出空格。

    Shown below are two examples of ethers with their IUPAC names.
    ::下面显示两个带有IUPAC名称的醚的例子。

    Chemical structures of two ethers labeled with their IUPAC names to demonstrate ether naming.

     

     

    Properties of Ethers
    ::以太的属性

    Like , ethers are also quite soluble in water. The lone-pair electrons on the oxygen atom of the ether can form a with the hydrogen atoms of water molecules. As with alcohols, the is greater for ethers that have shorter length R groups. The boiling points of ethers are much lower than the boiling points of alcohols. Ether molecules do not have hydrogen atoms that are covalently bonded to a highly electronegative atom, and so ether molecules cannot form hydrogen bonds with each other. The weaker intermolecular force acting between ether molecules results in boiling points which are much closer to alkanes of similar than to alcohols.
    ::类似, 醚在水中也相当容易溶解。 醚氧原子上的单体电子可以与水分子的氢原子形成一种。 与酒精一样, 酒精对长度较短的R组的醚来说更大。 醚的沸点比酒精的沸点要低得多。 醚分子没有氢原子,这些原子与高电阴性原子交织在一起, 因此醚分子无法形成氢联结。 醚分子之间作用较弱的分子力量导致沸点, 与酒精相近的烷相近。

    The anesthetic effects of ethers were first discovered in the 1840s. Diethyl ether was used as a general anesthetic for patients undergoing surgery for many years. However, ethers are very flammable and have undesirable side effects such as nausea and vomiting. Safer alternatives to ethers are now used in anesthesia and the primary use of ethers today is as a solvent for other organic compounds.
    ::乙醚的审美效应是1840年代首次发现的。二乙醚是多年来进行外科手术的病人的一般麻醉用物,但是,乙醚非常易燃,具有不良副作用,如恶心和呕吐。现在,乙醚的更安全替代品被用于麻醉,目前主要使用乙醚作为其他有机化合物的溶剂。

    Review
    ::回顾

    1. What is the generic formula for an ether?
      ::一种醚的通用公式是什么?
    2. Do ethers boil at higher or lower temperatures than the alcohol with a similar structure?
      ::与结构相似的酒精相比,醚在高温或低温下沸腾吗?
    3. Why are ethers water-soluble?
      ::为什么醚能溶解水?