Rawar da Hanyoyin Sodium Cyanide a cikin Tsarin Halitta

Gabatarwa

Sodium Cyanide (NaCN), wani farin lu'ulu'u mai ƙarfi wanda ke narkewa cikin ruwa, tushe ne mai ƙarfi kuma mai ƙarfi na nucleophile, wanda hakan ya sa ya zama mai amfani a cikin haɗakar Organic . Duk da yawan gubarsa, wanda ke buƙatar tsauraran matakan tsaro yayin sarrafawa, Sodium cyanide yana taka muhimmiyar rawa wajen haɗa nau'ikan mahadi na organic, gami da magunguna, sinadarai na noma, da polymers.

Matsayin Sodium Cyanide a cikin Tsarin Halitta

Cyanide Ion a matsayin Nucleophile

Ion ɗin cyanide da ke cikin Sodium Cyanide wani nau'in nucleophile ne mai amsawa sosai. Godiya ga cajin da ba shi da kyau akan atom ɗin Carbon da kuma yawan electronegativity na atom ɗin nitrogen, yana iya kai hari ga cibiyoyin electrophilic a cikin ƙwayoyin halitta, kamar ƙungiyoyin carbonyl, alkyl halides, da epoxides.

Samuwar C-C Bonds

Ɗaya daga cikin muhimman ayyukan sodium cyanide a cikin haɗakar kwayoyin halitta shine ƙirƙirar sabbin haɗin carbon - carbon, wanda aka samu ta hanyar maye gurbin nucleophilic da kuma haɗa halayen. Misali, lokacin da alkyl halide ya yi hulɗa da sodium cyanide, cyanide ion yana maye gurbin halide ion, wanda ke haifar da samuwar nitrile. Wannan amsawar tana samar da hanya mai sauƙi don shigar da ƙarin ƙwayar carbon a cikin ƙwayar. Daga baya, ana iya canza ƙungiyar nitrile zuwa wasu ƙungiyoyi masu aiki kamar carboxylic acid, amines, ko aldehydes ta hanyar hanyoyin sinadarai daban-daban.

Haɗin Amino Acids - Ra'ayin Strecker

Sodium cyanide wani muhimmin sashi ne a cikin halayen Strecker, wanda ake amfani da shi don haɗin α-amino acid. A cikin wannan yanayin, aldehyde ko ketone suna haɗuwa da ammonium chloride da sodium cyanide don samar da α-amino nitrile. Wannan α-amino nitrile daga nan za a iya sanya ruwa don samar da α-amino acid daidai.

Halin yana bayyana a matakai da yawa: Na farko, ƙungiyar carbonyl na aldehyde ko ketone suna jurewa protonation, yana ƙara ƙarfin lantarki. Sa'an nan kuma, kwayar ammonia ta kai hari ga rukunin carbonyl da aka samar, sannan daga baya don samar da hemiaminal. Bayan haka, rukunin hydroxyl na hemiaminal yana haɓakawa, yana haifar da kawar da ruwa da samuwar ion iminium. Sa'an nan ion cyanide ya kai hari ga iminium ion don samar da α-amino nitrile. A ƙarshe, hydrolysis na α-amino nitrile a gaban acid ko tushe yana ba da α-amino acid.

Maganar Nitriles daga Aryl Halides - The Rosenmund - von Braun Reaction

A cikin amsawar Rosenmund - von Braun, ana amfani da sodium cyanide don canza aryl halides, waɗanda suke halogen - mahaɗan aromatic da aka maye gurbinsu, zuwa aryl nitriles. Catalyzed ta jan karfe (I) cyanide kuma yawanci yana buƙatar yanayin zafi, wannan yanayin ya ƙunshi samuwar jan ƙarfe - aryl matsakaici. Cyanide ion daga sodium cyanide sa'an nan ya amsa tare da wannan matsakaici don samar da aryl nitrile. Wannan tsari yana da mahimmanci don gabatar da ƙungiyar aikin nitrile akan zobe na kamshi, wanda za'a iya ƙara inganta shi don haɗa nau'ikan mahadi daban-daban, kamar magunguna da rini.

Haɗin Haɗin Carbonyl

Sodium cyanide kuma yana shiga cikin haɗin haɗin carbonyl. Misali, lokacin da yake amsawa da epoxide, ion cyanide yana kai hari ga ƙaramin atom ɗin carbon wanda aka maye gurbinsa da zoben epoxide, yana sa zoben ya buɗe. Sakamakon hydrolysis na cyanohydrin da ke biyo baya zai iya haifar da samuwar wani fili na carbonyl.

Hanyoyi na Abubuwan da suka shafi Sodium Cyanide

Matsalolin Sauyawar Nucleophilic

Tsarin SN2 : Lokacin da sodium cyanide ya yi aiki tare da manyan alkyl halides, amsawar yawanci tana bin tsarin SN2 (bimolecular nucleophilic maye gurbin). Cyanide ion yana kai hari ga ƙwayar carbon da aka haɗa da halogen daga bayan, akasin matsayin ion halide da ke barin. Wannan haɗin kai ne inda fashewar haɗin carbon - halogen da samuwar haɗin carbon - cyanide ke faruwa a lokaci guda. Yawan amsawar ya dogara ne akan yawan alkyl halide da ion cyanide, kuma stereochemistry na samfurin yana juyawa idan aka kwatanta da na kayan farawa.

Tsarin SN1 : Tare da tertiary alkyl halides, amsawar na iya ci gaba ta hanyar tsarin SN1 (wanda aka maye gurbin nucleophilic unimolecular). Da farko, alkyl halide yana rabuwa don samar da matsakaicin carbocation. Sannan, cyanide ion yana kai hari ga wannan carbocation don samar da samfurin. Tsarin SN1 yana da alaƙa da samuwar matsakaicin carbocation planar, kuma samfurin na iya nuna cakuda stereochemistries, wani abu da aka sani da racemization, saboda hare-haren nucleophile daga ɓangarorin biyu na planar carbocation.

Halayen Ƙarar Nucleophilic

Ƙarin Rukunin Carbonyl : Lokacin da sodium cyanide ya yi hulɗa da aldehydes ko ketones, ion cyanide yana kai hari ga zarra ta carbonyl carbon electrophilic. Ƙungiyar carbonyl tana da haɗin carbon - oxygen mai polarized, tare da zarra ta carbon shine wurin electrophilic. Harin ion cyanide yana ƙirƙirar sabon haɗin carbon - cyanide, kuma zarra ta oxygen na ƙungiyar carbonyl yana samun cajin negative. A mataki na gaba, tushen proton, kamar ruwa ko acid, yana samar da zarra ta oxygen don samar da cyanohydrin. Wannan amsawar za a iya mayar da ita, kuma ana iya daidaita daidaiton zuwa ga samfurin ta hanyar sarrafa yanayin amsawar.

Ƙari ga Imines : A cikin amsawar Strecker, ƙarin ion cyanide zuwa ion iminium, wanda aka samar daga amsawar aldehyde ko ketone tare da ammonia, yana bin irin wannan tsarin ƙara nucleophilic. Ion iminium yana da caji mai kyau akan atom ɗin nitrogen, yana sa atom ɗin carbon da ke kusa da shi ya zama electrophilic. Ion cyanide yana kai hari ga wannan atom ɗin carbon, yana samar da sabon haɗin carbon - cyanide kuma yana haifar da samuwar α - amino nitrile.

La'akari da Lafiya

Yana da mahimmanci a jaddada cewa sodium cyanide yana da guba sosai. Shakar numfashi, sha, ko haduwar fata tare da shi na iya zama m. Lokacin aiki tare da sodium cyanide, dole ne a bi tsauraran ka'idojin aminci. Wannan ya haɗa da gudanar da gwaje-gwaje a cikin rijiyar hayaƙi mai iska, sanye da kayan kariya masu dacewa kamar safar hannu, tabarau, da rigar lab, da samun ingantattun tsare-tsare na ba da agajin gaggawa a wurin idan abin ya faru cikin haɗari.

Kammalawa

Sodium cyanide ne mai ƙarfi da kuma m reagent a cikin kwayoyin kira. Ƙarfinsa na yin aiki azaman nucleophile da ƙirƙirar sabon carbon-carbon bond ya sa ya zama kayan aiki mai mahimmanci ga masanan sunadarai wajen haɗa nau'ikan mahadi masu yawa. Fahimtar hanyoyin amsawa da suka haɗa da sodium cyanide yana da mahimmanci don ƙirƙira ingantattun hanyoyin haɗin gwiwa da tsinkayar sakamako. Duk da haka, saboda yawan gubarsa, dole ne a tsara amfani da shi a hankali kuma a aiwatar da shi tare da cikakkiyar kariya ta aminci don kiyaye lafiyar masanan sunadarai da muhalli.