Esters: general halaye da kuma aikace-aikace

Esters na - canzawa kayayyakin na hydrogen atoms na hydroxyl kungiyoyin na carboxylic acid da kuma ma'adinai acid a carbon m. Rarrabe mono-, di- da polyesters. zama na daya, di- da polybasic acid, monobasic acid don - cike da kuma acid esters. Title ester kunshi wani sunan, da hannu a cikin samuwar acid da kuma barasa. Domin esters, akai-akai amfani da nan maras muhimmanci ko tarihi nomenclature. A cewar IUPAC nomenclature sunayen esters suna kafa kamar haka: dauki wani m title barasa ya kara da cewa a matsayin hydrocarbon acid sunan da kuma kawo karshen -oat. Alal misali, tsarin dabarbari na esters (da isomers metamers) m da kwayoyin dabara S4N802, da daban-daban nomenclatures an mai suna: propilformiat (propilmetanoat) izopropilformiat (izopripilmetanoat), ethyl acetate (etiletanoat) melpropionat (methylpropanoate).

Shiri na esters. Wadannan mahadi aka yadu rarraba a yanayi. Saboda haka, esters na low kwayoyin nauyi da kuma matsakaici carboxylic acid homologue jerin wani bangare ne na da muhimmanci mai yawa shuke-shuke (msl, uksusnoizoamilovy ester ko "pear ainihi", wanda shi ne wani ɓangare na pears da yawa launuka), da kuma esters na glycerol kuma mafi girma m acid - sinadaran tushen duk mai da mai. Wasu esters an shirya synthetically.

A esterification dauki daukan wuri da hulda da carboxylic (da kuma ma'adinai) acid tare da alcohols. A kara kuzari abubuwa a matsayin wani karfi da ma'adinai acid (fi amfani da H2S04). A kara kuzari kwayoyin activates da carboxylic acid.

A dauki kudi na esterification dogara kuma a kan Associated OH kungiyar (primary, secondary ko manyan) tare da wani carbon zarra a kan sinadaran da yanayin da acid da kuma barasa da kuma hydrocarbon sarkar tsarin, wanda ake dangantawa da carboxyl.

Hydrolysis da esters. A hydrolysis dauki (saponification) esters - ne kuma baya da dauki na esterification. Yana wuce sannu a hankali. Idan kara zuwa da dauki cakuda, da cakuda ma'adinai acid ko alkalis, ta gudu yana ƙaruwa. Alkali saponification daukan sanya dubu sau sauri fiye da acid. A esters ake hydrolyzed a wani alkaline matsakaici, da kuma ethers - a acid.

Bayan dumama esters da alcohols a gaban acid sulphate ko alcoholates (alkaline matsakaici) alkoxy musayar faruwa. Wannan suranta wani sabon ester, da kuma dauki matsakaici aka koma barasa, wanda a baya ya kasance a cikin nau'i na sharan a cikin ester kwayoyin.

Esters rage dauki. Rage jamiái ne mafi sau da yawa lithium aluminum hydride, sodium a ruwan barasa. Esters na high juriya ga mataki na daban-daban oxidants amfani da sinadaran kira ko analysis kare giya da phenolic kungiyoyin.

Esters babban wakilan. Ethyl ethanoate (acetic ether) da aka samu ta hanyar da esterification dauki na ethanol da acetate acid mai kara kuzari ( acid sulphate). Ethyl ethanoate aka yi amfani a matsayin sauran ƙarfi da cellulose nitrate a samar da smokeless gunpowder, da kuma daukar hoto fim, 'ya'yan essences gyara ga masana'antun sarrafa kayayyakin abinci.

Izoamiletanoat (uksusnoizoamilovy ether, "pear jigon") ne sosai narkewa a cikin ethanol, diethyl ether. Acetate da aka shirya esterification na acid da kuma isoamyl barasa. Izoamilmetilbutanoat amfani da wani dandano bangaren a perfumery da matsayin sauran ƙarfi.

Izoamilizovaleriat ( "apple" ainihi, izovalerianovoizoamilovy ether) da aka samu ta hanyar maida martani da esterification isovaleric acid da kuma isoamyl barasa. Ya ce ester aka yi amfani a matsayin 'ya'yan essences a masana'antun sarrafa kayayyakin abinci.