First‐principles calculation of second‐order elastic constants and equations of state for lithium azide,LiN3, and lead azide,Pb(N3)2

First‐principle techniques are used to calculate the second‐order elastic constants and equations of state for lithium azide, LiN₃, and lead azide, Pb(N₃)₂. The bulk modulus is calculated for these systems in two independent ways and results compared. The Hartree–Fock potential and density‐functional theory are used for the exchange correlation with different basis sets to examine the effects of each on the elastic constants and bulk modulus. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Developments on the Chemistry of Tellurium and Selenium Azides

Abstract

We have been carrying out systematic studies on the preparation and properties of tellurium halide and pseudohalide compounds with a focus on tellurium azides. We were successful in the synthesis of various tellurium azides of both covalent and ionic nature. Several tellurium(IV) azides, tellurium(II) azides, and the first tellurium(VI) azides can be prepared in reasonable amounts. The first structural information of selenium azides is obtained for covalent and ionic derivatives, and spectroscopic data for the existence of selenium(iv) polyazides.     

钠汞齐作为一种有用的还原试剂还原带有不同官能团的叠氮成相应的有机胺

Reduction of azides to amines without touching benzyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, trityl and tetrahydropyranyl ether protecting groups, C-C double and triple bond, as well as aromatic bromide and nitrile functional groups, was achieved using sodium amalgam as a reducing reagent in methanol at temperature from -40℃ to room temperature. However, ester group was reduced under this condition.     

Synthesis,Stability and Reactivity of α-Fluorinated Azidoalkanes

Organic α-fluorinated azidoalkanes appeared in the literature for the first time half a century ago. However, for a long time they remained undeveloped and were regarded as chemical curiosities. Recent advances in the preparation of α-fluorinated azidoalkanes as well as studies on their stability and reactivity opened up their broader synthetic potential for the preparation of valuable fluorinated and non-fluorinated compounds.     

Chinazolinone, 3. Mitt.: α-Alkylolamide aus Aziden der Chinazolinonreihe

0-Acylated N-alkylolamides3 were prepared from the quinazolinyl-azides1 by heating1 in acetic anhydride. Cleavage of the ester moiety by acetic acid yielded the free alkylolamides4. Possible reaction mechanisms are discussed.

     

A convergent synthesis of (17R,5Z,8Z,11Z,14Z)-17-hydroxyeicosa-5,8,11,14-tetraenoic acid analogues and their tritiated derivatives

17(R)-OH-AA and 14,15-dehydro-17(R)-OH-AA were synthesized from a common tetraacetylenic precursor and their azide derivatives were obtained in moderate yields via the corresponding p-toluenesulfonates. Since the azido group remained stable during tritiation procedure on Lindlar's catalyst in benzene, both 14,15-dehydro-17(S)-N₃-AA and 14,15-dehydro-17(R)-OH-AA constitute useful intermediates in the synthesis of radio-labelled 17(S)-N₃-AA and 17(R)-OH-AA. In contrast, reduction of azide in methanol afforded 17(S)-NH₂-AA with 95% yield.     

State of alkali azides in zeolites studied by thermal analysis

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.     

Reactions of Vinyl Azides

This review is designed to demonstrate the versatility of vinyl azides in organic reactions. The reactive azide function is susceptible to thermolysis, photolysis, cycloadditions, and attack by nucleophiles and electrophiles. The neighboring double bond accentuates the reactivity of the azide function and provides additional intramolecular pathways for reaction. Last but not least, the presence of an appreciable electron density at the β-vinyl carbon makes this class of compounds comparable with enamines in their reactions with electrophiles and 1,3-dipoles.     

Chemistry of Tetradentate [C,N : C,N] Iminophosphorane Palladacycles: Preparation,Reactivity and Theoretical Calculations

A theoretical and experimental study of tetradentate [C,N : C,N] iminophosphorane palladacycles was carried out for the purpose of elucidating their behavior as compared to the parent Schiff base analogues to determine the prospect of encountering new A-frame structures for the iminophosphorane derivatives. The DFT calculations were in agreement with the experimental results regarding the performance of these ligands. New insights into the chemistry of the related dinuclear species have been obtained.     

Solid‐State Hierarchical Cyclodextrin‐Based Supramolecular Polymer Constructed by Primary,Secondary, and Tertiary Azido Interactions

The crystallization of a di‐azido‐α‐cyclodextrin revealed a polymeric self‐assembly involving a variety of azido‐type interactions. The crystal arrangement relies on the cooperativity of a primary azido inclusion, a secondary azido–azido interaction involving an unprecedented distribution of canonical forms, and a tertiary azido–groove interaction. The second azido group brings in a major contribution to the supramolecular structure illustrating the benefit of a difunctionalization for the generation of hierarchy.     

Reactions of Halogen Azides

Until recently, the explosive nature of halogen azides made these compounds unsuitable for preparative uses and greatly impeded investigation of their physical properties. Reactions of ClN₃ and BrN₃ with metal halides, metal carbonyls, and organometallic compounds to from metal azide halides, nitride halides, carbonyl azide halides, and alkylmetal azides were reported only very recently. The stability relationships of the halogen azides are discussed.     

Synthesis and structures of trifluoromethyl-, fluoro-, and azido-substituted hexabenzylhexaazaisowurtzitanes and isolation of a novel hexaazaisowurtzitane-based polycycle

The first hexabenzylhexaazaisowurtzitane cage compounds with trifluoromethyl and azide groups, as well as those with fluorine atoms in the 3- and 4-positions, have been prepared and fully characterized. A study of the substituent influence on the benzene ring regarding the formation of the hexaazaisowurtzitane polycycle in either the 2- or 4-position with CF(3), F, and N(3) revealed an interesting difference. In all cases with CF(3), F, and N(3) substituents in the 4-position, the corresponding hexabenzylhexaazaisowurtzitanes were isolated. The corresponding hexabenzylhexaazaisowurtzitanes were also formed when these substituents were in the 2-position; however, in addition with azide in 2-position a novel type of polycycle was isolated and identified. (15)N NMR data and crystal structures of hexabenzylhexaazaisowurtzitane derivatives were obtained and are discussed in detail.     

SYNTHESIS,SPECTROSCOPIC STUDIES,AND X-RAY CRYSTAL STRUCTURE OF N-HETERYLIMINOPHOSPHORANES

N-[2-(α-Bromoacetyl)phenyl]imides (prepared in two steps from 2-aminoacetophenone) gave, upon treatment with sodium azide, fused azidoquinolines via an intramolecular cyclization. Reaction of the above azides with phosphines gave N-heteryliminophosphoranes. The IR, ¹H-, ¹³C-, and ³¹P-NMR and MS spectra of these compounds as well as the x-ray crystal structure of two of them is reported.