Ethers have carbon chains (two alkyl groups ) therefore the constitutional isomerism possibilities in ethers depend on: The partitioning of carbon atoms between the two alkyl groups, and Isomerism possibilities for the individual alkyl groups present. Isomerism is not possible for a C2 or a C3 ether C4 and C5 ethers exhibit constitutional isomers. Functional Group Isomerism Ethers and alcohols with the same number of carbon atoms and the same degree of saturation have the same molecular formula. For example: Dimethyl ether, and ethyl alcohol both have the molecular formula C2H6O (constitutional isomers). Functional group isomers are constitutional isomers that contain different functional groups. C3 ether–alcohol functional group isomerism possibilities are three (see below) 14.18 Physical and Chemical Properties of Ethers Physical Properties: The boiling points of ethers are similar to those of alkanes of comparable molecular mass and are much lower than those of alcohols of comparable molecular mass. Ethers more soluble in water than alkanes of similar molar mass because ethers can hydrogen bond Chemical Properties: Ethers are Flammable, e.g., Diethyl has boiling point of 35oC and therefore a flash-fire hazard. Ethers react slowly with oxygen from the air to form unstable hydroperoxides and peroxides. Unreactive towards acids, bases and oxidizing agents (useful for organic reactions) Like alkanes, ethers also undergo halogenation reactions Cyclic Ethers Contain the ether functional groups as part of a ring system (heterocyclic organic compounds).
Ethers have carbon chains (two alkyl groups ) therefore the constitutional isomerism possibilities in ethers depend on: The partitioning of carbon atoms between the two alkyl groups, and Isomerism possibilities for the individual alkyl groups present. Isomerism is not possible for a C2 or a C3 ether C4 and C5 ethers exhibit constitutional isomers. Functional Group Isomerism Ethers and alcohols with the same number of carbon atoms and the same degree of saturation have the same molecular formula. For example: Dimethyl ether, and ethyl alcohol both have the molecular formula C2H6O (constitutional isomers). Functional group isomers are constitutional isomers that contain different functional groups. C3 ether–alcohol functional group isomerism possibilities are three (see below) 14.18 Physical and Chemical Properties of Ethers Physical Properties: The boiling points of ethers are similar to those of alkanes of comparable molecular mass and are much lower than those of alcohols of comparable molecular mass. Ethers more soluble in water than alkanes of similar molar mass because ethers can hydrogen bond Chemical Properties: Ethers are Flammable, e.g., Diethyl has boiling point of 35oC and therefore a flash-fire hazard. Ethers react slowly with oxygen from the air to form unstable hydroperoxides and peroxides. Unreactive towards acids, bases and oxidizing agents (useful for organic reactions) Like alkanes, ethers also undergo halogenation reactions Cyclic Ethers Contain the ether functional groups as part of a ring system (heterocyclic organic compounds).
Notes-C14-121.docx