
In organic chemistry and biochemistry esters are substances that have the functional group '''(R-COO-R') (the carbon is double-bonded to one oxygen atom and single-bonded to another) and consist of an alkane united with the residue of any oxygen acid, organic or inorganic. An ester is a product of the reaction of an acid (usually organic acid) and an alcohol (the hydrogen of the acid R-COOH is replaced by an alkyl group R\"). Esters mainly result from the condensation reaction (this is, a reaction that produces water) of a carboxylic acid and an alcohol. The process is called esterification. This reaction can be catalysed by the presence of H+ ions. Sulphuric acid is often used as a catalyst for this reaction. The name ester is derived from the German Essig-Aether''', an old name for acetic acid ethyl ester (ethyl acetate). This is the general displayed formula of an ester: ==Naming of esters== Esters can be produced by an equilibrium reaction between an alcohol and a carboxylic acid. The ester is named according to the alkyl group (the part from the alcohol) and acetate (the part from the carboxylic acid) which make it up; for example, the reaction between methanol and butanoic acid yields the ester methyl butanoate (as well as water). The simplest ester is H-COO-CH3 (methyl formate, also called methyl methanoate). The hydrogen atom on the left can be replaced with a CH3 group or additional CH2 units, producing other methyl esters, including methyl stearate, a component of biodiesel. ==Physicals== Esters can participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding makes them more water soluble than their parent hydrocarbons. However, the limitations on their hydrogen bonding also make them more hydrophobic than either their parent alcohols or parent acids. Their lack of hydrogen bond donating ability means that ester molecules cannot hydrogen bond to each other, which makes esters generally more volatile than an carboxylic acid of similar molecular weight. 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 analysed using gas chromatography, gas liquid chromatography, or mass spectrometry. Many esters have distinctive odors, which has led to their widespread use as artificial flavorings and fragrances. For example: :methyl butanoate smells of pineapple :methyl salicylate (oil of wintergreen) smells of the ointments called Germolene™ and Ralgex™ in the UK :methyl benzoate smells of marzipan :ethyl methanoate smells of raspberry :ethyl butanoate smells of pineapple :ethyl salicylate smells of mint :pentyl ethanoate smells of banana :pentyl pentanoate smells of apple :pentyl butanoate smells of pear or apricot :octyl ethanoate smells of orange (fruit) Esters may undergo hydrolysis - the breakdown of an ester by water. This process can be catalyzed both by acids and bases. The base-catalyzed process is called saponification. The hydrolysis yields an alcohol and a carboxylic acid or its carboxylate salt. == See also == * Polyester == External links == * [http://www.chm.bris.ac.uk/motm/ethylacetate/ethylh.htm Molecule of the month: Ethyl acetate and other esters] Functional groups Esters lv:Esteri
I think the ester_compound page should be moved back here. The other pages are not as important as the chemistry one, except for the ester, alaska one but a note at the top of the page would suffice for that. Ester final fantasy is trivial and esther i the bible is not even the same spelling. Its not called an ester compound anyway, if anything it should just be ester (chemistry). User:Borb 08:28, 6 May 2005 (UTC) ---- It might do to describe which isomer of the pentyl radicals are refered to in some of the esters given. *Given that one-carbon differences in chain length lead to distinguishable odors, and that different optical isomers of odorants/flavorants (eg, carvone) lead to distinguishable odors, I would be *very* surprised if there were not also a dependency on pentyl chain isomerism. ---- Could anyone explain how the term mono-ester and di-ester is used? *This page needs a bit on mono, di and poly esters (I linked it to polyester page already, but thats also not very good). Basically a monoester is just an ester (one ester) a di-ester is two esters bonded together (the same way as polyesters). ---- If anyone has the rules handy (I don't right now), a description of the IUPAC method for naming esters would be handy. User:24.118.220.84 06:36, 5 May 2004 (UTC) == Chemical properties == I was frustrated by the lack of information on the chemical properties of esters. Are the reactions listed the only ones that it usually goes through? Could someone please post more information? :The reaction(s) listed are not the only ones esters can undergo. A discussion of all the reactions esters can be involved in can fill up an entire chapter of an organic chemistry book. It's not practical to list them all in a general encyclopedia. Some day, when I have time, I might do some work on this esters article. User:H Padleckas 09:19, 10 Dec 2004 (UTC) :I'll get some info up in the future. == move ester compound back? == yes, the ester content did move to ester compound because other ester (esther) definitions started to pop up. feel free though to revert this edit back to the original but please consider a solution for the other definitions.
See other meanings of words starting from letter:
Words begining with Ester:
Ester
Ester
Ester,_AK
Ester,_Alaska
Ester,_Alaska
Esterbrook,_WY
Esterbrook,_Wyoming
Esterel
Esterfication
Esterhazy
Esterhazy
Esterhazy
Esterházy
Esterhazy_Family
Esterhazy_of_Galantha
Esterification
Esterification
Esterified
Esterilla
Estero
Estero,_FL
Estero,_Florida
Esters
Esters
Ester_(disambiguation)
Ester_Boserup
Ester_boserup
Ester_compound
Ester_Fanous
Ester
In organic chemistry and biochemistry esters are substances that have the functional group '''(R-COO-R') (the carbon is double-bonded to one oxygen atom and single-bonded to another) and consist of an alkane united with the residue of any oxygen acid, organic or inorganic. An ester is a product of the reaction of an acid (usually organic acid) and an alcohol (the hydrogen of the acid R-COOH is replaced by an alkyl group R\"). Esters mainly result from the condensation reaction (this is, a reaction that produces water) of a carboxylic acid and an alcohol. The process is called esterification. This reaction can be catalysed by the presence of H+ ions. Sulphuric acid is often used as a catalyst for this reaction. The name ester is derived from the German Essig-Aether''', an old name for acetic acid ethyl ester (ethyl acetate). This is the general displayed formula of an ester: ==Naming of esters== Esters can be produced by an equilibrium reaction between an alcohol and a carboxylic acid. The ester is named according to the alkyl group (the part from the alcohol) and acetate (the part from the carboxylic acid) which make it up; for example, the reaction between methanol and butanoic acid yields the ester methyl butanoate (as well as water). The simplest ester is H-COO-CH3 (methyl formate, also called methyl methanoate). The hydrogen atom on the left can be replaced with a CH3 group or additional CH2 units, producing other methyl esters, including methyl stearate, a component of biodiesel. ==Physicals== Esters can participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding makes them more water soluble than their parent hydrocarbons. However, the limitations on their hydrogen bonding also make them more hydrophobic than either their parent alcohols or parent acids. Their lack of hydrogen bond donating ability means that ester molecules cannot hydrogen bond to each other, which makes esters generally more volatile than an carboxylic acid of similar molecular weight. 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 analysed using gas chromatography, gas liquid chromatography, or mass spectrometry. Many esters have distinctive odors, which has led to their widespread use as artificial flavorings and fragrances. For example: :methyl butanoate smells of pineapple :methyl salicylate (oil of wintergreen) smells of the ointments called Germolene™ and Ralgex™ in the UK :methyl benzoate smells of marzipan :ethyl methanoate smells of raspberry :ethyl butanoate smells of pineapple :ethyl salicylate smells of mint :pentyl ethanoate smells of banana :pentyl pentanoate smells of apple :pentyl butanoate smells of pear or apricot :octyl ethanoate smells of orange (fruit) Esters may undergo hydrolysis - the breakdown of an ester by water. This process can be catalyzed both by acids and bases. The base-catalyzed process is called saponification. The hydrolysis yields an alcohol and a carboxylic acid or its carboxylate salt. == See also == * Polyester == External links == * [http://www.chm.bris.ac.uk/motm/ethylacetate/ethylh.htm Molecule of the month: Ethyl acetate and other esters] Functional groups Esters lv:Esteri
Ester
I think the ester_compound page should be moved back here. The other pages are not as important as the chemistry one, except for the ester, alaska one but a note at the top of the page would suffice for that. Ester final fantasy is trivial and esther i the bible is not even the same spelling. Its not called an ester compound anyway, if anything it should just be ester (chemistry). User:Borb 08:28, 6 May 2005 (UTC) ---- It might do to describe which isomer of the pentyl radicals are refered to in some of the esters given. *Given that one-carbon differences in chain length lead to distinguishable odors, and that different optical isomers of odorants/flavorants (eg, carvone) lead to distinguishable odors, I would be *very* surprised if there were not also a dependency on pentyl chain isomerism. ---- Could anyone explain how the term mono-ester and di-ester is used? *This page needs a bit on mono, di and poly esters (I linked it to polyester page already, but thats also not very good). Basically a monoester is just an ester (one ester) a di-ester is two esters bonded together (the same way as polyesters). ---- If anyone has the rules handy (I don't right now), a description of the IUPAC method for naming esters would be handy. User:24.118.220.84 06:36, 5 May 2004 (UTC) == Chemical properties == I was frustrated by the lack of information on the chemical properties of esters. Are the reactions listed the only ones that it usually goes through? Could someone please post more information? :The reaction(s) listed are not the only ones esters can undergo. A discussion of all the reactions esters can be involved in can fill up an entire chapter of an organic chemistry book. It's not practical to list them all in a general encyclopedia. Some day, when I have time, I might do some work on this esters article. User:H Padleckas 09:19, 10 Dec 2004 (UTC) :I'll get some info up in the future. == move ester compound back? == yes, the ester content did move to ester compound because other ester (esther) definitions started to pop up. feel free though to revert this edit back to the original but please consider a solution for the other definitions.
See other meanings of words starting from letter:
E
EA | EB | EC | ED | EF | EG | EH | EI | EJ | EK | EL | EM | EN | EO | EP | ER | ES | ET | EU | EW | EX | EY | EZ |Words begining with Ester:
Ester
Ester
Ester,_AK
Ester,_Alaska
Ester,_Alaska
Esterbrook,_WY
Esterbrook,_Wyoming
Esterel
Esterfication
Esterhazy
Esterhazy
Esterhazy
Esterházy
Esterhazy_Family
Esterhazy_of_Galantha
Esterification
Esterification
Esterified
Esterilla
Estero
Estero,_FL
Estero,_Florida
Esters
Esters
Ester_(disambiguation)
Ester_Boserup
Ester_boserup
Ester_compound
Ester_Fanous
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