Azides of Cobalt

The normal cobalt(II) azide, Co(N3)2 xH20, is a reddish-brown, hygroscopic solid which dissolves readily in water the solution hydrolyzes slowly. It explodes with high brisance when shocked thermally or mechanicahy. Its sensitivity is considered the highest of all metal azides [54,143]. 

It was made by dissolving finely ground cobalt carbonate in ethereal hydrazoic acid. After 3-4 days the clear solution is evaporated to obtain reddish-brown crystals. The product, which retains some water tenaciously, is best stored protected from light under ethereal hydrazoic acid [156]. In another approach, cobalt carbonate was dissolved in aqueous hydrazoic acid and the solution concentrated to obtain a basic azide. This was again dissolved in strong hydrazoic acid to produce the reddish-brown crystals. The product was considered to be Co(N3)2 [157] but was not analyzed. 

A basic product of the approximate composition (OH)Co(N3) is made by heating an aqueous cobalt azide solution to precipitate a violet solid. Dipositive cobalt forms a tetraazidocobaltate(II) complex, [Co (N3)4] , in aqueous cobalt(II) salt solutions with a 15-fold sodium azide excess at pH 5 and may be 

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K3[Co(CN)6] is important in the production of certain lasers.66 Azides of cobalt ammines have been suggested as detonators, but appear to be inferior to lead and silver azides, which are in general use.66... 

See AZIDE COMPLEXES of cobalt(IH) See related metal azides... 

Complex 165 reacts with CO at room temperature to give />-tolyl isocyanate and the golden dicarbonyl compound 166. The latter can also be generated by reaction of 164 with excess of CO and converted back to imide 165 by the addition of 2 equiv of /> toly 1 azide (2003JA322). Reaction of cobalt(m) imide 167 analogous to 165, available from [PhB(CH2PPh2)3]CoI 156 by the same procedure as for 165, with CO proceeds similarly <2002JA11238>. 

ACYL AZIDES, AMMINECOB ALT (III) AZIDES, AZIDE COMPLEXES OF COBALT(III)... 

When acido groups, halides, thiocyanate, azide, acetate, and nitrate are present in the coordination sphere of cobalt(III), they appear to be oxidized in preference to coordinated ammonia. Many of the radicals thus produced are capable of oxidizing ammonia released from the complex or of interfering in other ways with the reduction process, and these systems have proved very difficult to understand even in general terms. Quantum yield and other data for a number of acidopentammine and certain other complexes are given in Table IV the data on the aquation reactions of some of the complexes are considered in Section I1I-D. 

Joyner et al, "Explosive Sensitivity of Cobalt Ammine Azides , Nature 196, No 4893(1962) 8) M.M. Braidech, "National... 

Cobalt Triazide (formerly call Cobalt Tri-nitride or Cobalt Azoimide) Co(N,)j, raw 142.99, N58.78% red-brn crysts (anhyd), mp det 148° (0.02 g in 5 sec) (Ref 5), hygroscopic and easily hydrolyzed (Ref 4). The basic cobalt azide, Co(OH)N, was first prepd in 1898 by Curtius Rissom (Ref 1). An aq soln of cobalt azide was studied by Dennis Isham (Ref 2). The anhyd salt, prepd by ihe action of cobaitous carbonate on hydrazoic acid, was prepd by Wohler (Ref 3) and by Wohler Si Martin MptKrvrl C nf nr hrt... 

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