Many esters have distinctive odors, which has led to their use as artificial flavorings and fragrances. This property makes them very useful in organic analytical chemistry: Unknown organic acids with low volatility can often be esterified into a volatile ester, which can then be analyzed using gas chromatography, gas liquid chromatography, or mass spectrometry. Their lack of hydrogen-bond-donating ability means that ester molecules cannot hydrogen-bond to each other, which, in general, makes esters more volatile than a carboxylic acid of similar molecular weight. However, the limitations on their hydrogen bonding also make them more hydrophobic than either their parent alcohols or their parent acids. This ability to participate in hydrogen bonding makes them more water- soluble than their parent hydrocarbons. Įsters of aromatic acids are also encountered, including benzoates such as methyl benzoate, and phthalates, with substitution allowed in the name.Įsters participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. It could also be called methyl methanoate. For example, methyl formate is the ester of methanol and methanoic acid (formic acid): the simplest ester. For esters from more complex carboxylic acids, the systematic name for the acid is used, followed by the suffix -oate. For esters derived from the simplest carboxylic acids, the traditional name for the acid constituent is generally retained, e.g., formate, acetate, propionate, butyrate. Since most esters are derived from carboxylic acids, a specific nomenclature is used for them. An ester is named according to the two parts that make it up: the part from the alcohol and the part from the acid (in that order), for example ethyl sulfuric acid ester.
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