Siyanid sahifasining manbasini koʻrish

[[Kimyo|Kimyoda]] '''siyanid''' [[kimyoviy birikma]] bo'lib, {{Chem2|C\tN}} o'z ichiga olgan [[Funktsional guruh|funksional guruh]]. '''Siano guruhi''' Hidrosiyan kislotasi deb nomlanuvchi bu guruh [[azot]] atomiga bog'langan [[Uglerod|uchta uglerod]] atomidan iborat<ref>[[IUPAC Gold Book]] [http://goldbook.iupac.org/C01486.html ''cyanides'']</ref>. 

[[Noorganik moddalar|Noorganik]] siyanidlarda siyanid guruhi anion sifatida mavjud {{Chem2|\sC\tN}} . [[Natriy siyanid]] (NaCN) va [[Kaliy siyanidi|kaliy siyanid]] (KCN) kabi eruvchan [[tuzlar]] juda zaharli hisoblanadi<ref name="CMC">{{Veb manbasi|url=http://www.cyanidecode.org/cyanide_environmental.php|sarlavha=Environmental and Health Effects of Cyanide|nashriyot=International Cyanide Management Institute|yil=2006|qaralgan sana=4 August 2009|arxivsana=30 November 2012|arxivurl=https://web.archive.org/web/20121130094124/http://www.cyanidecode.org/cyanide_environmental.php}}</ref>. [[Sianid|Hidrosiyan kislotasi]], shuningdek, vodorod siyanidi yoki HCN sifatida ham ishlatiladi, sanoatda keng miqyosda ishlab chiqariladigan juda [[uchuvchan]] suyuqlik bo'lib, uni siyanid tuzlariga kislotala ta'sir ettirish orqali olinadi.

[[Organik]] siyanidlar odatda [[nitril]] deb ataladi. Nitrillarda, {{Chem2|C\tN}} guruhi uglerod bilan [[Kovalent bog|kovalent bog']] hosil qilib bog'lanadi. Masalan, [[asetonitrilda]] ({{Chem2|CH3\sC\tN}} ), siyanid guruhi [[Metil guruhi|metil]] bilan bog'langan ({{Chem2|\sCH3}}). Nitrillar tarkibidagi siyanid ionlari ya'ni, [[siyanogidrinlar]] juda zaharli modda hisoblanadi. 

== Bog'lanishi ==
Sianid ioni {{Chem2|-C\tN}} [[Is gazi|uglerod oksidi]] {{Chem2|-C\tO+}} va molekulyar [[azot]] N≡N bilan [[izoelektron]]. C va N o'rtasida uch tomonlama bog'lanish mavjud. Manfiy zaryad C [[Uglerod|uglerodda]] to'planadi.  

== Hodisalari ==

=== Tabiatda ===
[[Fayl:Removal_of_cyanide_poison_from_cassava.jpg|left|thumb| [[Nigeriya|Nigeriyada]] [[kassavadan]] siyanidni olib tashlash.]]
Siyanidlar ma'lum [[bakteriyalar]], [[Zamburugʻlar|zamburug'lar]] va [[Suvoʻtlar|suv o'tlaridan]] tayyorlanadi. Sianidlar ma'lum urug'lar va meva toshlarida, masalan, [[achchiq bodom]], [[o'rik]], [[olma]] va [[Shaftoli|shaftolida]] katta miqdorda bo'ladi<ref>{{Veb manbasi|url=http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=71&tid=19|sarlavha=ToxFAQs for Cyanide|qaralgan sana=2008-06-28|sana=July 2006|nashriyot=[[Agency for Toxic Substances and Disease Registry]]|arxivsana=2019-06-14|arxivurl=https://web.archive.org/web/20190614144336/https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=71&tid=19}}</ref>. Tarkibida sianid bo'lgan kimyoviy birikmalar siyanogen birikmalar deb nomlanadi. O'simliklarda siyanidlar odatda siyanogen [[glikozidlar]] shaklida [[Qand|shakar]] molekulalari bilan bog'lanadi va o'simlikni [[Fitofaglar|o'txo'rlardan]] himoya qiladi. Tropik mamlakatlarda yetishtiriladigan [[Kartoshka|kartoshkaga]] o'xshash muhim oziq-ovqat bo'lgan [[kassava]] ildizlari siyanogen glikozidlarni o'z ichiga oladi<ref>{{Cite journal|first1=J.|last=Vetter|title=Plant cyanogenic glycosides|url=https://archive.org/details/sim_toxicon_2000-01_38_1/page/11|journal=Toxicon|year=2000|volume=38|pages=11–36|doi=10.1016/S0041-0101(99)00128-2|pmid=10669009|issue=1}}</ref><ref name="jones">{{Cite journal|first1=D. A.|last=Jones|title=Why are so many food plants cyanogenic?|url=https://archive.org/details/sim_phytochemistry_1998-01_47_2/page/155|journal=[[Phytochemistry (journal)|Phytochemistry]]|year=1998|volume=47|pages=155–162|doi=10.1016/S0031-9422(97)00425-1|pmid=9431670|issue=2}}</ref>.  

[[Madagaskar]] ''[[bambukini]]'' iste'molini to'xtatuvchi vosita sifatida siyanid ishlab chiqaradi. Bunga javoban, bambukni iste'mol qiladigan [[oltin bambuk lemuri]] siyanidga nisbatan yuqori chidamlilikni talab qiladi.

=== Yulduzlararo muhiti ===
[[Sianid radikali]] •CN [[Kosmos|yulduzlararo fazoda]] aniqlangan<ref>{{Cite journal|last=Pieniazek|first1=Piotr A.|last2=Bradforth, Stephen E.|last3=Krylov, Anna I.|title=Spectroscopy of the Cyano Radical in an Aqueous Environment|date=2005-12-07|pages=4854–65|issue=14|volume=110|url=http://www-bcf.usc.edu/~krylov/pubs/pdf/jpca-110-4854.pdf|journal=The Journal of Physical Chemistry A|pmid=16599455|doi=10.1021/jp0545952|bibcode=2006JPCA..110.4854P|access-date=2008-08-23|archiveurl=https://web.archive.org/web/20080911131555/http://www-bcf.usc.edu/~krylov/pubs/pdf/jpca-110-4854.pdf|archivedate=2008-09-11}}</ref>. [[Siyanogen]] {{Chem2|(CN)2}} [[yulduzlararo gaz bulutlarining]] haroratini o'lchash uchun ishlatiladi<ref>{{Cite journal|title=Interstellar Cyanogen and the Temperature of the Cosmic Microwave Background Radiation|last=Roth, K. C.|last2=Meyer, D. M.|last3=Hawkins, I.|journal=The Astrophysical Journal|year=1993|volume=413|issue=2|pages=L67–L71|doi=10.1086/186961|bibcode=1993ApJ...413L..67R|url=http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993ApJ...413L..67R&amp;data_type=PDF_HIGH&amp;whole_paper=YES&amp;type=PRINTER&amp;filetype=.pdf}}</ref>. 

=== Piroliz va yonish mahsuloti ===
Vodorod siyanidi kislorod tanqisligi sharoitida ma'lum materiallarning yonishi yoki [[pirolizlanishi]] natijasida hosil bo'ladi. Masalan, [[Ichki yonuv dvigateli|ichki yonuv dvigatellarining]] chiqindisi va [[tamaki]] tutunida kuzatilishi mumkin. Ba'zi [[Plastik materiallar|plastmassalar]], ya'ni [[Akrilonitril|akrilonitrillar]] tarkibidagi moddani qizdirilganda yoki yondirilganda vodorod siyanidini hosil qiladi<ref name="CDC">{{Veb manbasi|url=https://emergency.cdc.gov/agent/cyanide/basics/facts.asp|sarlavha=Facts about cyanide:Where cyanide is found and how it is used|muallif=Anon|sana=June 27, 2013|ish=CDC Emergency preparedness and response|nashriyot=Centers for Disease Control and Prevention|qaralgan sana=10 December 2016}}</ref>. 

=== Kofaktori ===
[[Gidrogenaza]] fermentlari faol joylarida temirga biriktirilgan siyanid [[Ligand|ligandlarini]] o'z ichiga oladi. [NiFe]-gidrogenazalarda siyanidning biosintezi [[Karbamoil fosfatdan|karbamoil fosfat]] bilan reaksiyaga kirishib, [[sisteinil]] [[tiosiyanatga]] {{Chem2|CN−}} aylanadi<ref>{{Cite journal|last=Reissmann|first1=Stefanie|last2=Hochleitner|first2=Elisabeth|last3=Wang|first3=Haofan|last4=Paschos|first4=Athanasios|last5=Lottspeich|first5=Friedrich|last6=Glass|first6=Richard S.|last7=Böck|first7=August|title=Taming of a Poison: Biosynthesis of the NiFe-Hydrogenase Cyanide Ligands|journal=Science|volume=299|issue=5609|pages=1067–70|year=2003|pmid=12586941|doi=10.1126/science.1080972|bibcode=2003Sci...299.1067R|url=http://pdfs.semanticscholar.org/d359/5a5928df6c6209f88e105c937ccce0a05237.pdf}}</ref>.

=== Organik hosilalari ===
[[IUPAC nomenklaturasida]] [[-C≡N]] [[funktsional guruhiga]] ega bo'lgan [[organik birikmalar]] nitril deb nomlanadi<ref>[[IUPAC Gold Book]] [http://goldbook.iupac.org/N04151.html ''nitriles'']</ref><ref>NCBI-MeSH [https://www.ncbi.nlm.nih.gov/mesh/68009570 ''Nitriles'']</ref>. Nitrilga [[Asetonitril|asetonitrilni]] {{Chem2|CH3\sC\tN}} misol qilib olishimiz mumkin. Nitrillar odatda siyanid ionlarini hosil qilmaydi va bir xil uglerod atomiga bog'langan gidroksil –OH va siyanid –CN bo'lgan funksional guruhga [[siyanogidrin]] (C(–OH)(–CN)) deyiladi. Nitrillardan farqli o'laroq, siyanohidridinlar [[Sianid|vodorod siyanidini]] chiqaradi. Noorganik kimyoda o'z ichiga olgan tuz{{Chem2|−C≡N}} ionlari siyanidlar deb ataladi.

== Reaksiyalari ==

=== Protonatsiya ===
Vodorod siyanidining p''K''<sub>a</sub>-9,21 ga teng. Siyanid tuzlarining eritmalariga vodorod siyaniddan kuchliroq [[Kislota|kislotalar]] ta'sir ettirilganda vodorod [[Sianid|siyanidni]] siqib chiqaradi.

=== Gidrolizi ===
Sianid suvda beqaror, ammo reaksiya 170°C gacha sekin boradi. U siyaniddan ancha kam zaharli bo'lgan [[ammiak]] va [[format]] hosil qilib [[Gidroliz|gidrolizga]] uchraydi.

: <chem>CN- + 2 H2O -> HCO2- + NH3</chem>

[[Sianid gidrolaza]] bu reaksiyani katalizlovchi [[Fermentlar|ferment hisoblanadi]] .

=== Alkillanishi ===
Sianid anionining [[nukleofilligi]] yuqori bo'lganligi sababli, siyanoguruhlar [[galoid]] guruhini ([[metilxloriddagi xlorid]]) almashtirish orqali organik molekulalarga osonlikcha birikadi. Umuman olganda, organik siyanidlar nitrillar deb ataladi. Organik sintezda siyanid C-1 ya'ni, [[wiktionary:functionalize|funksiyalash]] qobiliyatini saqlab qolgan holda, uglerod zanjirini bittaga uzaytirish uchun ishlatiladi. 

: <chem>RX + CN- -> RCN + X-</chem>

== Ishlab chiqarilishi ==
Sianidlarni ishlab chiqarishda ishlatiladigan asosiy jarayon [[kislorod]] va [[platina]] [[Kataliz|katalizatori]] ishtirokida [[metan]] va [[Ammiak|ammiakdan]] gazsimon [[Sianid|vodorod siyanidi]] ishlab chiqariladigan [[Andrussov jarayonidir|Andrussov jarayonlardir]]<ref>{{Cite journal|title=Über die schnell verlaufenden katalytischen Prozesse in strömenden Gasen und die Ammoniak-Oxydation (V)|trans_title=About the quicka catalytic processes in flowing gases and the ammonia oxidation (V)|language=de|authorlink1=Leonid Andrussow|first1=Leonid|last=Andrussow|journal=Berichte der Deutschen Chemischen Gesellschaft|volume=60|issue=8|pages=2005–18|year=1927|doi=10.1002/cber.19270600857}}</ref><ref>{{Cite journal|title=Über die katalytische Oxydation von Ammoniak-Methan-Gemischen zu Blausäure|trans_title=About the catalytic oxidation of ammonia-methane mixtures to cyanide|language=de|first1=L.|last=Andrussow|journal=[[Angewandte Chemie]]|volume=48|issue=37|pages=593–5|year=1935|doi=10.1002/ange.19350483702|bibcode=1935AngCh..48..593A}}</ref>.  

: <chem>2 CH4 + 2 NH3 + 3 O2 -> 2 HCN + 6 H2O</chem>

Ko'pgina siyanidlarning hosilasi bo'lgan natriy siyanidi [[Sianid|vodorod siyanidni]] [[natriy gidroksid]] bilan reaksiyaga kirishishi orqali ishlab chiqariladi.

: <chem>HCN + NaOH -> NaCN + H2O</chem>

== Sianid uchun kimyoviy sinovlar ==
Sianid miqdorini oltin qazib olishda keng qo'llaniladigan [[potentsiometrik titrlash]] usuli orqali aniqlanadi. Uni kumush ioni bilan titrlash orqali ham aniqlash mumkin. Ba'zi tahlillarda qaynab turgan eritmani havo bilan tozalash, bug'larni asosiy absorber eritmaga aylantiradi va asosiy eritmadan chiqadigan siyanid tuzi tahlil qilinadi. 

=== Sifatli testlar ===
Sianidni zaharli modda bo'lagani uchun ko'plab usullar bilan tekshiriladi. Masalan, benzidin [[ferrisiyanid]] ishtirokida ko'k rang beradi. [[Natriy sintezi sinovidan|Natriy sintezining]] filtrat qilingan siyanid eritmasiga qo'shilgan [[Temir kuporosi|temir (II) sulfat]]  [[Prussiya ko'k rangini|ko'k rangni]] beradi. [[DMSOdagi para -benzokinon|DMSOdagi ''para —'' benzokinon]] [[Fenol|eritmasi]] [[noorganik]] siyanid bilan reaksiyaga kirishib, [[Fluoressensiya|fluoresan]] bo'lgan siyanofenolni hosil qiladi. Agar test ijobiy bo'lsa, [[Ultrabinafsha nurlanish|UV nuri]] ta'sirida yashil/ko'k rangni namayon qiladi<ref>{{Cite journal|doi=10.1016/0041-008X(80)90225-2|pmid=7423496|title=Fluorometric determination of cyanide in biological fluids with p-benzoquinone*1|first4=JL|last4=Way|first3=RL|last3=Morgan|first2=GE|year=1980|last2=Isom|last=Ganjeloo|first1=A|journal=[[Toxicology and Applied Pharmacology]]|volume=55|issue=1|pages=103–7}}</ref>. 

== Manbalar ==
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== Havolalar ==

* [http://www.atsdr.cdc.gov/mmg/mmg.asp?id=1073&tid=19 ATSDR siyanid bilan zaharlanishni tibbiy boshqarish bo'yicha ko'rsatmalar (AQSh)] {{Webarxiv|url=https://web.archive.org/web/20100528070140/http://www.atsdr.cdc.gov/MMG/MMG.asp?id=1073&tid=19 |date=2010-05-28 }}
* [http://www.hse.gov.uk/pubns/firindex.htm Sianid bilan zaharlanishda birinchi yordamni davolash uchun HSE tavsiyalari (Buyuk Britaniya)]
* [http://www.inchem.org/documents/cicads/cicads/cicad61.htm Vodorod siyanidi va siyanidlari] ( CICAD 61)
* [http://www.inchem.org/documents/antidote/antidote/ant02.htm#SubSectionNumber:1.13.1 IPCS/CEC Sianidlar bilan zaharlanish uchun antidotlarni baholash]
* [https://web.archive.org/web/20060517035532/http://www.npi.gov.au/database/substance-info/profiles/29.html Milliy ifloslantiruvchi moddalar inventarizatsiyasi - siyanid birikmalari faktlar varaqasi]
* [http://www.snopes.com/food/warnings/apples.asp#add Kichik miqdordagi siyanidga qaramay, olma urug'ini iste'mol qilish xavfsizdir]
* [http://www.atsdr.cdc.gov/toxprofiles/tp8.pdf Sianid uchun toksikologik profil, AQSh Sog'liqni saqlash va inson xizmatlari departamenti, 2006 yil iyul]
[[Turkum:Anionlar]]
[[Turkum:Sianidlar]]
[[Turkum:Qon agentlari]]