GENERAL CHEMICAL SAFETY INFORMATION

SOP for the Use and Generation of Azide Ion and Organic Azides

Hazards

  • Azideionhasasimilartoxicityasthatofcyanideion(LD50=27mg/kgforrats).
  • Organicazidesarepotentially-explosive substancesthatcanandwilldecomposeunder heat,lightorpressure.
  • Smallmoleculescontainingazidofunctionalitytend todecomposeviolentlywhichmayresultininjuryifpropersafetyprecautions arenot utilized.

Handling

General:

  • Useonlyinthe chemicalfumehood.Minimizedustgenerationandaccumulation.
  • Wear the proper protective gear: flame resistant lab coat, splash goggles, rubber gloves, closed shoes.
  • Avoidcontactwith eyes,skinandclothing.

Sodium Azide:

  • Sodiumazidecanreactviolentlywithseveralcommonlaboratoryorganicssuch as:CS2,bromine,Bronsteadacids,andheavymetals.Whenattemptinganew reaction,berelentlessinyourbackground researchtodeterminethereactivityof sodiumazideanionstoallreactioncomponents.
  • Neveruse chlorinatedsolventsasreactionmedia! Using dichloromethane orchloroformwillresultintheformationofdi-andtri- azidomethane,respectively(refertosectionon C/Nratiosbelow).

Organic Azides:

  • Allorganicazidesdecomposewithintroductionofexternalenergy.Anyazide synthesizedshouldbestoredbelowroomtemperature(-18oC)andinthedark.
  • Whendesigningyourtargetazide,keepinmindthefollowingequation.1)Notice thatthisequationtakesintoaccountallnitrogenatomsinyourazide,notjust thoseintheazidogroup. Nsignifiesthenumberof atoms.

Nc+No/NN≥ 3 (eq.1)

  • Inpractice,organicazidesthatcontradicttheaboveequation canbemade,andin somecases,bestoredsafely.Considerthefollowingpointsasstrictguidelines in thepreparation andstorageoforganicazides:
  • Asmallscale(ca.0.5-1.0g)shouldberunfirsttodetermine thenatureof theproduct.
  • n-nonylazide(C/N=3)willbethesmallest azideisolatedandstoredinits pureform.Thisazide,whenstoredproperly, canbedonesoinmultigram quantities (upto20g).Inpractice,theoctylderivative isequallysafe (C/N=2.7)
  • AzidessmallerthanC/N=3(butgreaterthanC/N=1)canbesynthesized andisolated,butnomeansshouldthesemolecules bestoredinitshighest purity.Rather,ifstorageisnecessarystoretheseazidesassolutionsbelow roomtemperature(concentrated tonomorethan1M,lessthan5g material). Explicit supervisor approval may be necessary before attempting synthesis.
  • Undernocircumstances shouldazideswithC/N<1beisolated.However, thesemoleculesmayonlybeconsideredforsynthesized ifazideisa transientintermediate species,andthelimitingreagentinthereaction mixture,andwithmaximum quantitiesof1g. Explicit supervisor approval may be necessary before attempting synthesis.
  • Neverusedistillationorsublimation as purificationtechniques! Purification shouldbelimitedtoextractionandprecipitation.Columnchromatographymay contributetodecomposition. Onlyazidesthatsatisfyeq.1 may be purified in this manner.

Disposal

Organicazidewaste shouldbeplacedinaseparate,explicitly-labeledwaste container!Extracautionmustbetakentomake surethatazidewaste notcomeincontactwithacid.Acidswillprotonateany residualazideionandformthe highly-toxichydrogenazide(withtoxicitysimilartothatof hydrogencyanide).

Reference

1. Smith,P.A.S.Open-ChainNitrogenCompounds,vol2,Benjamin,NewYork,

1966, 211-265.