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Photolysis of anhydrous NiN6 at 30° under the action of high pressure Hg arc is reported. The sample for photolysis studies is prepared by treating aqueous nickel azide solution with excess of AnalaR dimethyl ketone. The pressure of N developed during photolysis under steady state conditions at constant intensity is a linear function oft 1/2 and dark rate analysis suggests that the dependence ont 1/2 should be due to the diffusion of N from reaction site to the surface of solid azide. Absence of photoconduction in the wavelength range of the irradiating radiation suggests that excitons are the reactive species and the linear dependence of the rate of photolysis on intensity is interpreted in terms of the reaction of a trapped exciton with adjacent azide ion.

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Abstract  

The paper describes the synthesis of low molecular mass poly(allyl chloride) (PAC) (M n= 856-3834 g mol-1) using Lewis acid (ALCL3, FeCL3, TiCL4) and al powder. Branching in PAC was indicated on the basis of elemental analysis and 1H-NMR spectroscopy. azidation of pac could be carried out at 100°C by using NaN3 and DMSO as solvent. Curing of poly(allyl azide) (PAA) by cyclic dipolar addition reaction with EGDMA (ethylene glycol dimethacrylate, 5-45 phr) was investigated by differential scanning calorimetry and structure of cured polymer was confirmed by FTIR. A two-step mass loss was exhibited by uncured and cured PAA in nitrogen atmosphere. A mass loss of 20-28% (155-274°C) and 50-61% (330-550°C) was observed.

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Thermal behaviour of pure LiN3, NaN3, CsN3 and their mixture with the respective LiY-FAU, NaY-FAU, CsY-FAU zeolite was investigated by means of thermogravimetry and IR spectroscopy. Thermodesorption of CO2 was applied to compare the basicity of the alkali ionexchanged Y zeolites. Two of the investigated systems, the NaN3/NaY-FAU and the CsN3/CsY-FAU gave single, well defined and reproducible azide decomposition features rendering these samples to apply as catalyst precursors for preparation of zeolite with basic character.

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Abstract  

The thermal decomposition (TD) of 2-azidophenylmethanol (1), 2-azidobenzenecarbaldehyde (2), 1-(2-azidophenyl)-1-ethanone (3), (2-azidophenyl)(phenyl)methanone (4) and 1-azido-2-nitrobenzene (5) was analysed by DSC, TG and C80 calorimetric techniques under both oxidative and non-oxidative conditions. The TD of these azides in solution is well known to give the corresponding benzoxazoles, generally in good yields, with the exception of azide 1. When both the outcomes from the solid phase and in ‘solution phase’ TD reactions combined with the results from EI-MS experiments were considered, sufficient information was available to estimate the azides intrinsic molecular reactivity (MIR).

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Journal of Flow Chemistry
Authors: Hanspeter Sprecher, M. Nieves Pérez Payán, Michael Weber, Goekcen Yilmaz, and Gregor Wille

Abstract

The synthesis and utilisation of acyl azides in a flow apparatus combined with an automated extraction unit is described. This process safely provides multi-100 g quantities of a labile diacyl azide (3) as an intermediate that could not be generated safely by classic batch methods. Its subsequent conversion to the desired amine (4) represents an example for process intensification. The same set-up with an output capacity of >30 g/h was used for the unattended synthesis of benzoyl azide as the final product in solution (tert-butyl methyl ether (TBME), 0.5 M).

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Reaction between iodine and the azide ion induced by heterocyclic thiols has been used for detection in TLC and HPTLC. The developed plates were sprayed with a freshly prepared solution of sodium azide and starch, adjusted to a pH within the range 5.5–6.0, and then exposed to iodine vapor. The thiols became visible as white spots on a violet-gray background. The iodine-azide reagent enabled detection of quantities in the range 1–80 pmol per spot. The iodine-azide test was compared with other visualizing techniques commonly used in planar chromatography (iodine vapor and UV 254 ). The method was applied to detection of 2-thioguanine and 6-mercaptopurine in biological samples.

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The paper presents the application of post-chromatographic iodine-azide reaction for the determination of three thiouracils (6-benzyl-, 6-methyl-, and 6-propyl-2-thiouracil) in high-performance thin-layer chromatography (HPTLC). The HPTLC plates developed by methanol were sprayed with a freshly prepared mixture of sodium azide, potassium iodide, and starch solution adjusted to pH 5.5, and exposed to iodine vapour for 5 s. Because of the induction properties of the C-S and C=S bonds of thiouracil molecule in the iodine-azide reaction, the spots became visible as white spots on a violet-brown background.Scanning of the HPTLC plates was performed on a PC scanner and analysed by TLSee software. Determination range was 7–16 pmol per spot, 80–160 nmol per mL of urine, or 133–266 nmol per 1 mL of serum.

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Abstract  

Reactions of At//+, Ato.H2O, AtCl 2 and AtBr2 with the pseudohalogenides tricyanomethanide and azide are described. Information on the compound formation of astatine with C/CN/ 3 and N 3 could be obtained on the basis of electromigration investigations under variation of the conditions /composition of the electrolyte, pH, exchange reactions of ligands/. For the reaction: [At/H2O/C/CN/3]+C/CN/ 3 [At/C/CN/3/2]+H2O at 301 K and u=0.075 mol.l–1 K2=/675±25/ [1.mol–1] and uo=–/3.50±0.10/×10–4 [cm2.s–1.V–1]. According to this astatine/I/-tricyanomethanide is classified between AtI 2 and At/SCN/ 2 . First investigations in azid-containing systems confirm the formation of astatine/I/-azide-compounds. Their composition is probably At/N3/ 2 . There is no dependence of the ion mobility of astatine/I/-azide in the investigated range on azide concentration which is due to its high stability.

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Abstract  

Bis-N,N′(salicylidene)-2,2′-dimethyl-1,3-propanediamine (LDMH2) has a high tendency to form polynuclear complexes. Two trinuclear complexes were obtained using this ligand and azide ions; (CuLDM)2 · Mn(N3)2 · (DMF)2, [(C19H20N2O2Cu)2 · Mn(N3)2 · (C3H7NO)2] and (CuLDM)2 · Cd(N3)2 · (DMF)2, [(C19H20N2O2Cu)2 · Cd(N3)2 · (C3H7NO)2]. The structures were identified with X-ray methods. TG and DSC methods were also employed to these complexes. Studies showed the (CuLDM)2 · Mn(N3)2 · (DMF)2 and (CuLDM)2 · Cd(N3)2 · (DMF)2 to be non-linear. Also μ-bridges were not encountered for the azide ions but were seen to form between the Cu and other metal via phenolic oxygens. Thermal analysis showed exothermic degradation of the azide ions destroying the trinuclear structure. Although azide containing structures show explosive characteristics, this was not observed for the present compounds.

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Journal of Flow Chemistry
Authors: Sara Sadler, Meaghan M. Sebeika, Nicholas L. Kern, David E. Bell, Chloe A. Laverack, Devan J. Wilkins, Alexander R. Moeller, Benjamin C. Nicolaysen, Paige N. Kozlowski, Charlotte Wiles, Robert J. Tinder, and Graham B. Jones

Abstract

A facile and benign route to N-heterocycles, including triazoles and triazolopyrimidines, has been developed. Using continuous-flow microreactor technology, organic azides are prepared in situ and reacted with cyanoacetamide in a [3+2] cycloaddition to produce a variety of substituted 1,2,3-triazoles, which can be elaborated into useful building blocks. A benzyl-substituted triazole was further functionalized to an analog of the core structure of the antiplatelet agent Brilinta®. The methodology lends itself well to flow chemistry, where reaction volumes are minimized, heating and mixing are consistent, and the need for intermediate azide isolation bypassed. The scope of the process is wide, and the efficiency is high, suggesting this as a practical, green route for the production of triazolo-based heterocycles.

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