Tsakanin Tsakanin

Tsakanin Criegee (wanda ake kira Criegee zwitterion ko Criegee biradical) shine carbonyl oxide tare da cibiyoyin caji guda biyu. Wadannan sunadarai na iya amsawa tare da sulfur dioxide da nitrogen oxides a cikin yanayin duniya, kuma suna da alaƙa da samar da aerosols, waɗanda ke da mahimmanci wajen sarrafa yanayin duniya. Criegee matsakaici kuma muhimmiyar tushen OH (hydroxyl radicals).  OH radicals sune mafi mahimmancin oxidant a cikin troposphere, kuma suna da mahimmanci wajen sarrafa ingancin iska da gurɓata.

An fara kafa irin wannan tsari a cikin shekarun 1950 ta hanyar Rudolf Criegee, [1] wanda aka sanya masa suna. Ba har zuwa 2012 ba ne aka ba da rahoton gano irin waɗannan sunadarai kai tsaye.[2] Infrared spectroscopy ya nuna cewa Tsarin lantarki yana da halayyar zwitterionic mai mahimmanci maimakon halayyar biradical da aka gabatar a baya.[3]￼

 Kafawa 
Tsakanin Criegee an kafa su ne ta hanyar halayen gas-phase na alkenes da ozone a cikin yanayin duniya. Ozone yana ƙarawa a fadin haɗin carbon-carbon na alkene don samar da molozonide, wanda sa'an nan kuma ya lalace don samar da carbonyl (RR'CO) da carbonyle oxide. Wannan na ƙarshe an san shi da Criegee matsakaici.

Halin alkene ozonolysis yana da matsananciyar zafi, yana saki kusan kilocalories 50 a kowace mole (210 kJ / mol) na yawan makamashi. Sabili da haka, an kafa matsakaiciyar Criegee tare da adadi mai yawa na makamashi na ciki.

 Cirewa 
Lokacin da aka kafa matsakaiciyar Criegee, wasu sassan su za su fuskanci lalacewar unimolecular, suna samar da ƙwayoyin OH da sauran samfuran. Koyaya, a maimakon haka suna iya daidaitawa ta hanyar hulɗa tare da wasu kwayoyin ko amsawa tare da wasu sunadarai don ba da samfuran daban-daban.

Criegee matsakaici na iya daidaitawa ta hanyar haɗuwa da wasu kwayoyin a cikin yanayi. Wadannan tsakiya na Criegee masu tsayayya na iya fuskantar lalacewar unimolecular na zafi zuwa OH radicals da sauran samfuran, ko kuma suna iya fuskantar halayen bimolecular tare da wasu nau'ikan yanayi.

A cikin jerin abubuwan da suka faru na ozonolysis, matsakaicin Criegee yana amsawa tare da wani fili na carbonyl (yawanci aldehyde ko ketone ta hanyar Criegee-tsakanin tsari da kansa) don samar da Ozonide (1,2,4-trioxolane).

 Manazarta 

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