Azide complexes

Detailed investigations indicated an interesting mechanism for azide openings catalyzed by 2 [6]. Chloride-epoxide addition products were observed in the initial stages of the ARO reaction with 2 in amounts commensurate with the catalyst loading. Azide complex 3, characterized as the TH F adduct, was isolated from the reaction mixture and proved to be an active and recyclable catalyst for the ARO, pointing to the role of 2 as that of a precatalyst. Kinetic experiments revealed a second-order dependence on the concentration of 3, a zero-order dependence on azide source, and inverse-order dependence on epoxide concentration. The sue-... 

Methylamine Hydrobromide Cupric Azide Complex, (MeNHa+)Cu(N3)2-Br-, CHgBrCuN , mw 259.61, N 37.77%. Dark violet crysts, mp 116°. It detonates with a hammer blow... 

Beck and Fehlhammer (18, 19) describe reactions of several metal azide complexes, including Au(N3)4, with isocyanides which yielded a tetrakis-(tetrazolato)aurate(I) species. The formation of Au(PPh3)C(OCH3)=N-p-... 

Treatment via chelation has been observed for 2-acetylpyridine thiosemi-carbazone derivatives, which have been found to possess inhibitory activity for the RNA-polymerases of the influenza virus [133]. The iron(III) complexes were shown to be 3 to 6 times more active as inhibitors of partially purified ribonucleotide reductase (no added iron) compared to uncomplexed thiosemi-carbazone [128]. Raina and Srivastava [134] prepared and characterized low spin iron(III) complexes of 2-acetylpyridine thiosemicarbazone, [Fe(8-H)2A] (A = NO3, OH, Cl, N3, NCS or NO2), which were proposed as being seven-coordinate. However, all but the azide complex are 1 1 electrolytes in DMF and their solid ESR spectra are rhombic with the g-values being about 2.20,2.15 and 2.00. Of the six complexes, the azide ion seems to interact ihost strongly with the iron(III) center. 

The Fe(lll)-azide-precursor and the photolysed product were characterized by NIS spectroscopy coupled to detailed DFT calculations [63]. The result of the study provides additional evidence in favor of a low-spin 5=1/2 ground state of the Fe(V)-nitrido complex. Here we show how first-principles calculations assist in quantitative analysis of experimental NIS data for the Fe(lll)-azide complex. 

Fig. 5.14 Experimental (a, black curve), fitted (a, red) and simulated (b) NIS spectrum of the Fe (Ill)-azide complex obtained at the BP86ATZVP level (J = 20 K). Bar graphs represent the corresponding intensities of the individual vibrational transitions. The blue curve represents the fitted spectrum with a background line removed (taken from [63])...

Figure 5.14 presents experimental, fitted, and purely quantum-chemically calculated NIS spectra of the ferric-azide complex. It is clear that the fitted trace perfectly describes the experimental spectra within the signal-to-noise ratio. Furthermore, the purely theoretical spectrum agrees well with the fitted spectrum. This indicates that the calculations provide highly realistic force field and normal mode composition factors for the molecule under smdy and are invaluable as a guide for least-square fittings. 

Table 5.9 Experimental and calculated at the BP86ATZVP level frequencies and corresponding values of the iron normal mode composition factors of the most important vibrations that appear in the NIS signal of the Fe(III)-azide complex (taken from [101])...

Fig. 5.15 Schematic representation of the normal modes of the Fe(ni)-azide complex with the largest iron composition factors. The individual displacements of the Fe nucleus are depicted by a blue arrow. All vibrations except for V4 are characterized by a significant involvement of bond stretching and bending coordinates (red arrows and archlines), hi such a case, the length of the arrows and archlines roughly indicate the relative amplitude of bond stretching and bending, respectively. Internal coordinates vibrating in antiphase are denoted by inward and outward arrows respectively (taken from [63])...

Perchlorate salts of the azide complexes, and also of the dichloro analogue, may present an explosion hazard. 

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

Fig. 41. (Left) Molecular structure of the azide complex 81 in the crystal. (Right) Central N3Ni(g-S)2( i,3-N3)NiN3 core in 81. The figures were generated using data downloaded from The Cambridge Crystallographic Data Center (CCDC) and correspond to the structure originally reported in Ref. (242).

The acceptor properties of Ni2 + are weaker than those of Co2 + and under analogous conditions the extent of complex formation is smaller. When sodium azide is added to a 10 3 molar nickel (II) perchlorate solution in excess, the only azide-complex is monoazidonickel (II). The monochloro complex is present only in strong hydrochloric acid 81L Due to the low solvating properties of DMA even tetrachloronickelate (II) is found in such solutions. 

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

A third example is the reaction of nitrite with the azide complex. I don t want to discuss this more. I think that Carl Brubaker would like to talk about this. 

M. Straumanis, ZAnorgChem 251, 343 4 (15 43) CA37, 6574(1943)iPrepn and props of some Cu azide complexes among them the diamminecopper(ll) azidei (See item Cul cable D) 36)H.J.Emeleus J,S.Anderson, Modern Aspects of Inorganic Chemistry,"... 

Chromium Azide Complexes In attempting to prepare Cr azide from a soln of CrfNOsX and NaNj in pyridine, Oliveri-Mandala (Ref 5)... 

Cobalt Azide Complexes — Curtius Rissom (Ref 1) found that potassium cobaltoazoimide,... 

Cupric Azide Complexes. Cupric azide forms numerous complex compds, such as [Cu (C8H,N)a](N,)a and [Cu(CaHl(NHa)J)a](Ns)a, wherein the azide group is analogous to the corresponding halides (Ref 8). The cupric pyridine azide, Cu(Ns)a 2Cs Hg N, mw 305.78,... 

An addn compd with mercuric cyanide, Hg(CN)a-Zn(N3)a, which deflagrated but did not explode when heated,was prepd by Ricca Pirrone (Ref 10) from aq sol ns of NaN, ZnS04 and Hg(CN)a. Strecker Schwinn (Ref 12) prepd some Zn azide complex salts, [Zn(CsHj N)a] (N,)a and [Zn (CjH NH jjJ (Na)a, and detd their props. A group of mixed Zn halogen azides of the type [ZnNIaNa] M were prepd by Vournazos (Ref 8),... 

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