Studies on Organophosphorus Compounds XI: The Reaction of Phosphorus Reagents With Hydrazonoyl Halides,Hydrazonoyl Azides,and Shiff's Bases

N-(chloro-furan-2-yl)methylene-N′-(4-nitrophenyl)hydrazone (I) reacted with triethylphosphite to produce the phosphonate derivative III. The tetrazine derivative VI was produced by the interaction of I with diethyl-phosphite. Hydrazonoyl azide derivatives VIIIa–c reacted with triphenyl phosphine to form the iminophosphorane derivatives Xa–c. On the other hand, the azide derivative VIIIc reacted with the phosphonium ylide XI to form the 1,2,3-triazole adduct XIII. The reaction of triethyl phosphite with Shiff's bases XIVa–c yielded the corresponding phosphonates XVa–c. The structures of the newly prepared compounds were confirmed with the analytical and spectroscopic evidences.     

Zinc Hydrazides and Alkoxyhydrazides: Organometallic Compounds with Novel Zn4N8, Zn4N6O and Zn4N4O2 Cage Structures

Tetrameric [{RZn(NHNMe₂)}₄] (R = Me, Et), the first organometallic zinc hydrazides to be described, have been prepared by alkane elimination from dialkylzinc solutions and N,N‐dimethylhydrazine. They were characterised by ¹H and ¹³C NMR and IR spectroscopy, mass spectrometry, elemental analysis and X‐ray crystallography. The compounds form asymmetric aggregates containing the novel Zn₄N₈ core; tetrahedra of Zn atoms bear the alkyl groups at Zn, with the triangular faces bridged by NHNMe₂ substituents. The NH groups are connected to two Zn atoms, and the NMe₂ groups to one. Hydrolysis of the compounds with water gives [(RZn)₄(OH)(NHNMe₂)₃] as products, which also were characterised as described above. Higher yields of these hydroxo clusters were achieved in one‐pot syntheses by reaction of dialkylzinc solutions with mixtures of N,N‐dimethylhydrazine and water. They contain Zn₄N₆O cages, in which one hydroxide in the tetrameric hydrazides described above replaces one NHNMe₂ group. Similar products can be prepared with alkoxy instead of hydroxy groups, in analogous one‐pot syntheses with alcohols. Alcoholysis of [EtZn(NHNMe₂)]₄ with methanol or ethanol gave zinc trishydrazide monoalkoxides, [(EtZn)₄(OR)(NHNMe₂)₃] (R = Me, Et), which have constitutions analogous to the monohydroxides. The organozinc bishydrazide bisalkoxides [(MeZn)₄(NHNMe₂)₂(OEt)₂] and [(EtZn)₄(NHNMe₂)₂(OEt)₂] were obtained in one‐pot reactions from dialkylzinc solutions with mixtures of the hydrazine and alcohol, and their crystal structures, confirmed by spectroscopic methods in solution, show an unsymmetrical aggregation with the novel Zn₄N₄O₂ cage structure.     

Cu/V2O5-TiO2的光催化丙烯和二氧化碳合成MAA反应性能

用IR、TPD、UV-Vis和微型光反应器技术研究了CO2和C3H6在Cu／V2O5-TiO2表面上的吸附特性和光催化反应性能．实验结果表明：在Cu／V2O5-TiO2催化剂表面存在金属位Cu、Lewis酸位V^5 和Ti^4 以及Lewis碱位V-O-Ti的桥氧和V=O的端氧三类活性中心；在金属位Cu和Lewis酸位Ti^4 (或V^5 )协同作用下．CO2形成活性较高的卧式吸附态Cu-(CO)-O→Ti^4 (或V^5 )．C3H6的β-H和β-C分别吸附在Lewis碱位V=O与金属位Cu上形成Cu-C(CH2CH3)-H→O=V吸附态；Cu／V2O5-TiO2催化剂的吸光阈值红移和光吸收量的提高均有利于其光催化活性的提高；担载10％V2O5的光催化剂催化活性优于其它含量的催化剂，其光量子效率达到15．1％；C3H6转化率为5．5％，MAA选择性超过95％．根据实验结果．提出了光促表面催化合成反应的机理．     

New CO2-philic Compounds： Design, Synthesis and Solubility in Supercritical Carbon Dioxide

Liquid and supercritical carbon dioxide (scCO2) have attracted much attention as “green” replacement for organic solvents, offering economical and environmental benefits due to its favorable physical and chemical properties, such as recyclability, ease …     

Studies on the System ZnO-V2O5-Fe2O3 Reactivity of ZnFe2O4 Towards ZnV2O6

Studies on the reactivity of ZnFe₂O₄ towards ZnV₂O₆ revealed that in the solid state the phases interact in a molar ratio of 1:3 to form a new compound, to which the molecular formula Zn₂FeV₃O₁₁ was assigned. The compound melts congruently at 825±5°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

Die Clusterazide M2[Nb6Cl12(N3)6]·(H2O)4—x (M = Ca,Sr, Ba)

The Cluster Azides M₂[Nb₆Cl₁₂(N₃)₆]·(H₂O)_4—x (M = Ca, Sr, Ba) The isotypic cluster compounds M₂[Nb₆Cl₁₂(N₃)₆] · (H₂O)_4—x (M = Ca (1) , M = Sr (2) and M = Ba (3) ) have been synthesized by the reaction of an aequeous solution of Nb₆Cl₁₄ with M(N₃)₂. 1 , 2 and 3 crystallize in the space group Fd3¯ (No. 227) with the lattice constants a = 1990.03(23), 2015.60(12) and 2043, 64(11) pm, respectively. All compounds contain isolated 16e— clusters whose terminal positions are all occupied by orientationally disordered azide ligands.     

Azidoberyllate mit Adamantanstruktur: Synthese,IR‐Spektren und Kristallstrukturen von (Ph4P)2[Be4X4(μ‐N3)6] (X = Cl,Br)

Azido Beryllates with Adamantan‐like Structures: Synthesis, IR Spectra, and Crystal Structures of (Ph₄P)₂[Be₄X₄(μ‐N₃)₆] (X = Cl, Br) The azido beryllates (Ph₄P)₂[Be₄X₄(μ‐N₃)₆] (X = Cl 1a , X = Br 1b ) have been prepared by the reaction of Me₃SiN₃ with the halogeno beryllates (Ph₄P)₂[Be₂Cl₆] and (Ph₄P)₂[Be₂Br₆], respectively, in CH₂Cl₂ and CH₂Br₂ solution, respectively. Both complexes form moisture sensitive, colourless crystals, which are nonexplosive with respect to mechanical or thermal stress. They are characterized by IR spectroscopy and by crystal structure determinations. 1a and 1b crystallize isotypically in the space group C2/c with 12 formula units per unit cell. Whereas 1a was only refined to R₁ = 0.13, which is caused by disordering, 1b could be refined to R₁ = 0.066. The structures contain adamantanlike dianions [Be₄X₄(μ‐N₃)₆]^2— with two symmetry nonequivalent individuals which differ only slightly from one another. The Be₄N₆ core is formed by bridging function of the α‐nitrogen atoms of the azide groups with BeN bond lengths of 172.5 and bond lengths N_α—N_β = 123.2 pm and N_β—N_γ = 113.1 pm on average in the structure of 1b .     

Application of Ionic Complex of N 2 O 4 with 18-Crown-6 as an Oxidizing Agent for the Oxidation of Organosulfur Compounds

Complexation of gaseous N 2 O 4 with 18-Crown-6 affords an ionic complex of NO + ·;18-crown-6·;H(NO 3 ) m 2 . This reagent is a nitrosating agent for conversion of thiols to thionitrites. Disulfides can be obtained from coupling of thiols via thionitrites. Moreover this reagent is an oxidizing agent for conversion of thioethers into their corresponding sulfoxides and dithianes into their carbonyl compounds in an oxidative deprotection reaction.     

Ein oktaedrischer Niobcluster mit sechs terminalen Azidgruppen: Die Struktur von Rb4[Nb6Br12(N3)6](H2O)2

An Octahedral Niobium Cluster containing Six Terminal Azide Groups: The Structure of Rb₄[Nb₆Br₁₂(N₃)₆](H₂O)₂ Six terminal halide ligands of [Nb₆Br₁₂Br₆]^4? can be substituted in solution by azide ions. Single-crystals of Rb₄[Nb₆Br₁₂(N₃)₆](H₂O)₂ were obtained during the evaporation of the water/methanol solvent, and structurally characterized by X-ray methods: Space group P2₁/c, Z = 2, a = 970.8(5) pm, b = 1525.4(7) pm, c = 1280.0(7) pm, β = 97.15(6)°. The [Nb₆Br₁₂(N₃)₆]^4? ions contain six terminal azide groups at the corners of the octahedral niobium cluster (d _Nb–N = 227 pm). The [Nb₆Br₁₂(N₃)₆]^4? ions are interconnected by Rb⁺ and H₂O. Crystals of Rb₄[Nb₆Br₁₂(N₃)₆](H₂O)₂ are explosive towards heat or mechanic pressure.     

Synthesis and Crystal Structure of the Azide K4[Re6Sei8(N3)a6]·4H2O; Luminescence,Redox, and DFT Investigations of the [Re6Sei8(N3)a6]4– Cluster Unit

The reaction of K₄[Re₆Seⁱ₈(OH)^a₆] · 8H₂O with NaN₃ in water results in the formation of [Re₆Seⁱ₈(N₃)^a]^4– units that crystallize with K⁺ and H₂O to form K₄[Re₆Seⁱ₈(N₃)^a₆] · 4H₂O [P2₁/c (N°14), a = 9.0595(3) Å, b = 13.2457(4) Å, c = 13.2040(5) Å, β = 94.472(1)°]. In the solid state, the unit is characterized by N₃ linear groups forming bond angles of roughly 120° with the Re₆ cluster. The positions of the ν_as and ν_sy bands as well as N–N–N deformation modes of the N₃ groups are discussed. Luminescence properties of the [Re₆Seⁱ₈(N₃)^a]^4– unit were measured in the solid state and in an acetonitrile solution. The redox potential of the [Re₆Seⁱ₈(N₃)^a]^4–/[Re₆Seⁱ₈(N₃)^a]^3– system was measured in acetonitrile. Experimental results were analyzed in the light of density functional theory calculations.     

ChemInform Abstract: Sulfur Compounds. Part 200. Structures and Energies of Various Isomers of Dithionous Acid,H2S2O4, and of Its Anion HS2O4-.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

Features of Protonation of the Simplest Weakly Basic Molecules,SO2, CO,N2O,CO2, and Others by Solid Carborane Superacids

An experimental study on protonation of simple weakly basic molecules (L) by the strongest solid superacid, H(CHB₁₁F₁₁), showed that basicity of SO₂ is high enough (during attachment to the acidic H atoms at partial pressure of 1 atm) to break the bridged H‐bonds of the polymeric acid and to form a mixture of solid mono‐ LH⁺???An^?, and disolvates, L?H⁺?L. With a decrease in the basicity of L=CO (via C), N₂O, and CO (via O), only proton monosolvates are formed, which approach L?H⁺?An^? species with convergence of the strengths of bridged H‐bonds. The molecules with the weakest basicity, such as CO₂ and weaker, when attached to the proton, cannot break the bridged H‐bond of the polymeric superacid, and the interaction stops at stage of physical adsorption. It is shown here that under the conditions of acid monomerization, it is possible to protonate such weak bases as CO₂, N₂, and Xe.     

A Theoretical Study of the Ion—Molecule Chemistry of K+×X Complexes (X: O,O2, N2, CO2, H2O): Implications for the Upper Atmosphere.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.     

Reaction with N,N‐Diethyl‐p‐phenylenediamine: A Procedure for the Sensitive Square‐Wave Voltammetric Detection of Chlorine

The reaction of chlorine and N,N‐diethyl‐p‐phenylenediamine has been studied as a means of generating an analytical voltammetric signal of much improved sensitivity and selectivity for the detection of the former than is possible via direct electrolysis. A reaction mechanism is suggested whereby the chlorine attacks the primary amine of DEPD to form the N‐chlorinated product that shows a much enhanced signal under conditions of square‐wave voltammetry than does chlorine itself. The analytical parameters were found to vary with concentration of DEPD and a linear range from 17 to 495 μM was achievable with a corresponding limit of detection of 6.8 μM     

具有生理活性的含氧、氮、硫杂原子螺环化合物的研究进展

综述了近年来部分具有生理活性螺环化合物的研究进展, 重点介绍了这类化合物的结构特征、生理活性和部分化合物的合成方法. 展望了该类螺环化合物的应用前景.     

ChemInform Abstract: Experimental and ab initio MO Studies on (H2,N,O)+ Ions in the Gas Phase: Characterization of the Isomers H2NO+, HNOH+, and NOH+ 2 and the Mechanism of Unimolecular Dehydrogenation of (H2,N,O)+

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

Stopped‐flow Spectrophotometric Study on the Reaction between Carbon Dioxide and [Co(NH3)4(H2O)2]3+ Ion in Aqueous Solution

Kinetics of the reaction of [tetraamminediaquacobalt(III)] perchlorate ion with carbon dioxide in aqueous solution was studied at various temperatures (5–25 °C), variable concentration of CO₂ (0.005M; 0.01M; 0.015M) and over the pH range 6.04–8.15 at a fixed ionic strength of solution (1 M NaClO₄). Investigations were carried out using stopped‐flow spectrophotometry in the range of 300 – 700 nm. The results enabled determination of the number of steps of the reaction studied. Based on the kinetic equations, rate constants were determined for each step. Finally, the mechanism of carbon dioxide uptake by [tetraamminediaquacobalt(III)] perchlorate ion was proposed and discussed.