Azides metal complexes

Numerous explosives are based on hydrazine and its derivatives, including the simple azide, nitrate, perchlorate, and diperchlorate salts. These are sometimes dissolved in anhydrous hydrazine for propeUant appUcations or in mixtures with other explosives (207). Hydrazine transition-metal complexes of nitrates, azides, and perchlorates are primary explosives (208). 

A number of studies have been reported concerning azide-isocyanide condensations to give tetrazoles. Early work by Beck and co-workers 18, 19) describes the addition of various isocyanides to metal azido species [Au(N3)4]", [Au(N3)2]", Au(PPh3)N3, and M(PPh3)2(N3)2, M = Pd, Pt, Hg. The products are carbon-bonded tetrazolato-metal complexes. It is not known whether metal isocyanide complexes are intermediates in these reactions. More recently inverse reactions with azide ion addition to metal isocyanide complexes were carried out, with similar results. From... 

Despite the volume of work concerned with metal-catalyzed decomposition of diazo compounds and carbenoid reactions 28>, relatively little work has been reported on the metal-catalyzed decomposition of sulphonyl azides. Some metal-aryl nitrene complexes have recently been isolated 29 31>. Nitro compounds have also been reduced to nitrene metal complexes with transition metal oxalates 32K... 

Copper catalyzes the decomposition of sulphonyl azides in benzene very slowly. When methanesulphonyl azide was boiled under reflux in benzene solution in the presence of an excess of freshly reduced copper powder, some decomposition occurred to give methanesulphonamide and azide was recovered 78>. Transition metal complexes have been found to exert a marked effect upon the yields of products and isomer ratios formed in the thermal decomposition of methanesulphonyl azide in methyl benzoate and in benzotrifluoride 36>. These results will be discussed in detail in the section on the properties of sulphonyl nitrenes and singlet and triplet behaviour. A sulphonyl nitrene-iron complex has recently been isolated 37> and more on this species will be reported soon. 

On the other hand, thermolysis of ferrocenylsulpkonyl azide (14) in aliphatic solvents may lead to the predominant formation of the amide (16) 17>. A 48.4% yield of (16) was obtained from the thermolysis in cyclohexane while an 85.45% yield of 16 was formed in cyclohexene. Photolysis of 14 in these solvents led to lower yields of sulphonamide 32.2% in cyclohexane, 28.2% in cyclohexene. This suggests again that a metal-nitrene complex is an intermediate in the thermolysis of 14 since hydrogen-abstraction appears to be an important made of reaction for such sulphonyl nitrene-metal complexes. Thus, benzenesulphonamide was the main product (37%) in the copper-catalyzed decomposition of the azide in cyclohexane, and the yield was not decreased (in fact, it increased to 49%) in the presence of hydroquinone 34>. On the other hand, no toluene-sulphonamide was reported from the reaction of dichloramine-T and zinc in cyclohexane. 

Sulphonyl nitrene-metal complexes also undergo insertion into aliphatic C—H bonds as witnessed by the insertion into dioxan on treatment with chloramine-T and copper 45> and into cyclohexane with di-chloramine-T and zinc 44> and into cyclohexene with benzenesulphonyl azide and copper 34> and with ferrocenylsulphonyl azide 25>. 

Nitrosalicylhydrazide, 2778 Scandium 3-nitrobenzoate, 3816 Silver osmate, 0034 Thallium bromate, 0260 Thallium(I) methanediazoate, 0458 Thallium(I) 2- or 4-nitrophenoxide, 2187 Thallium acz-phenylnitromethanide, 2723 See also METAL AZIDES, METAL CYANIDES (AND CYANO COMPLEXES), /V-MKTAL DERIVATIVES... 

METAL ACETYLIDES, METAL AZIDE HALIDES METAL AZIDES, METAL AZOTETRAZOLIDES METAL CYANIDES (AND CYANO COMPLEXES)... 

Jacobsen and coworkers discovered that chiral salicylimidato transition metal complexes activate epoxides in a stereoselective manner. The published mechanism indicates that one Cr° (salen)-N3 with (/ ,/ )-cyclohexyl backbone acts as Lewis acid and coordinates to the oxygen of PO, while a second catalyst molecule transfers the azide to the activated epoxide and thus opens the ring. The coplanar arrangement of the two chromium complexes prefers one enantiomer of PO and so induces stereochemical information [99,100, 121-129]. (cf. also Sect. 8.3) (Fig. 42). 

Many agents that reduce blood pressure in man have metal-complexing ability, including sodium azide, sodium thiocyanate, dimercaptopropanol, hydralazine and, possibly, sodium nitroprusside. 

Thermal decomposition under hydrogen of a series of pentacyanocobaltate complexes (CN-, N02-, NO- or N3- ligands) revealed that the latter complex is the most exothermic by far. Presence of iron powder suppresses hydrogen cyanide formation. See related METAL AZIDES, METAL CYANIDES(AND CYANO COMPLEXES)... 

See also METAL AZIDES, METAL CYANIDES(AND CYANO COMPLEXES), N-METAL DERIVATIVES... 

The formation of complexes of l,2,3,4-thiatriazole-5-thiol has been well described in CHEC-II(1996) 1,2,3,4-thiatriazole-5-thiol can form complexes with various metals such as palladium, nickel, platinum, cobalt, zinc, etc. <1996CHEC-II(4)691>. These complexes can be prepared either by cycloaddition reactions of carbon disulfide with metal complexes of azide anion (Equation 20) or directly from the sodium salt of l,2,3,4-thiatriazole-5-thiol with metal salts. For instance, the palladium-thiatriazole complex 179 can be obtained as shown in Equation (20) or it may be formed from palladium(ll) nitrate, triphenylphosphine, and sodium thiatriazolate-5-thiolate. It should be noted that complexes of azide ion react with carbon disulfide much faster than sodium azide itself. 

Fig. 6. Projection down the c axis for [Cu(qnl)2][PA]2 showing picryl azide molecules overlapping with only the organic portion of the metal complex (Ref. 31)...

In contrast, tetrazadienes, RN=N—N=NR, which are unknown in the free state, are found in a growing number of transition metal complexes. The ligands can be generated in situ from organic azides or diazonium cations and, following the discovery of Fe(MeNNNNMeXCO)3 by Dekker and Knox in 1967 (59), an extensive range of transition metal tetrazadiene complexes has been synthesized. Finally, several papers report theoretical calculations on the stability and structure of N4 ligands bound to transition metals (196-198). 

The complexes are usually made by interaction of NaN3 or AgN3 with metal halide or halide complexes. Azides of halogens and other non-metals are well known in addition to metal complexes examples are IN3 and Sb(N3)3. ... 

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