1 If the invitation says black tie, women should wear a floor-length, evening gown. 2  A tuxedo is mandatory if you're a man. 3  This is your chance to dress as if you were headed to the Oscars. 4  Black tie optional means that wearing a tuxedo or long evening gown is not mandatory, but guests should feel free to do so.
Ether is an organic functional group consisting of a disubstituted oxygen, or an oxygen atom bonded to 2 carbon atoms (if adjacent to a ketone, functional group is then called an ester).
The general structure of an ether. R and R' represent any alkyl or aryl substituent. Ethers (/ËiËÎ¸Ér/) are a class of organic compounds that contain an ether groupâan oxygen atom connected to two alkyl or aryl groups. They have the general formula RâOâRâ², where R and Râ² represent the alkyl or aryl groups.