Solvent-dependent luminescent Cu(I) framework based on 5-(4-pyridyl)tetrazole

A new Cu(Ι) coordination compound, Cu₄(L)₄·2EtOH (1), has been obtained from the solvothermal reaction of CuBr, HL (L=5-(4-pyridyl) tetrazole), EtOH and NH₃·H₂O. The structure determination reveals that 1 has a 2D network, where each Cu(I) atom adopts a trigonal coordination mode. The 2D networks stacked in an ABAB sequence through the π–π interaction to form a 3D supramolecular framework, giving a 1D channel along the b-axis. The TGA and powder XRD measurements reveal that the framework is stable after removal of the guest molecules. Gas (N₂) adsorption measurement was carried out for the framework. Framework 1 shows II sorption profile with N₂, which indicates that N₂ molecules cannot diffuse into the micropore and only surface adsorption occurs. The photoluminescent research shows that compound 1 displays an interesting solvent-dependent luminescence.     

Synthesis of new polyoxapolycarboxylic ligands for lanthanide(III) ions complexation

The multidentate polyoxapolycarboxylic ligands 1 and 2 were obtained by a two-step synthesis from easily available chemicals. Preliminary data on their coordination properties are reported.     

Heterocycles of biological importance. Part 2. Novel synthesis and pharmacological evaluation of 5-amino-3-alkyl-1-(2-pyridyl)pyrazoles and 5-amino-3-phenyl-1-(2-pyridyl)pyrazole from allenic or acetylenic nitriles and 2-hydrazinopyridine

2-Hydrazinopyridine reacts with allenic and acetylenic nitriles to give 5-amino-3-alkyl-1-(2-pyridyl)pyrazoles 6 in excellent yields. One of these compounds, 6e has been shown to possess anticonvulsant and anti-electroshock properties. Phenyl propynenitrile also reacts with hydrazinopyridine to give 5-amino-3-phenyl-1-(2-pyridyl)pyrazole ( 11 ) in quantitative yield.     

3-Amino-5-phenyl-1-(2-pyridyl)pyrrolidines. Synthesis and stereochemistry

Stereoselective syntheses of trans- and cis-3-amino-5-phenyl-1-(2-pyridyl)pyrrolidine ( 21 and 24 ) are reported. Evidence for the relative stereochemistries of 21 and 24 was obtained by preparation of the bicyclic lactams exo- and endo-7-phenyl-1,4-diazabicyclo[3.2.1.]octan-3-one ( 16 and 19 ) from precursors of 21 and 24 .     

Gelation of La(III) cations promoted by 5-(2-pyridyl)tetrazolate and water

Addition of water to the product formed when LaCl3 and 1H-5-(2-pyridyl)tetrazole (LH) were treated with an excess of triethylamine in ethanol, resulted in the reversible formation of a hydrogel, which when further treated with EtOH-iPrOH produced crystals of [LaL3(H2O)3].(H2O)4, as determined by X-ray crystallography.     

Structure and properties of 1-(2-pyridyl)-3-phenyl-5-arylformazans

A series of 1-(2-pyridyl)-3-phenyl-5-arylformazans, which form deeply colored complexes with Zn²⁺, Cu²⁺, Co²⁺, and Ni²⁺ salts, were obtained by coupling of arenediazonium salts, containing various substituants in the phenyl ring, with benzaldehyde 2-pyridylhydrazone. The presence of a nitro group causes deepening of the color and leads to the appearance of negative solvatochromism.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1379–1381, October, 1972.     

Preparation of 3(5)-phenyl-1-hydroxypyrazole 2-oxide and 4-methyl-3(5)-phenyl-1-hydroxypyrazole 2-oxide

Nitrosation of acrylophenone oxime or of methacrylophenone oxime with n-butyl nitrite in the presence of pyridine and copper(II) sulfate gives the copper complexes of the title compounds. The free 1-hydroxypyrazole 2 -oxides are isolated by treating the copper complexes with dilute sodium hydroxide, filtration, and acidification of the basic filtrates. The title compounds are the first examples of 1-hydroxypyrazole 2 -oxides in which the C3(5) ring position is unsubstituted.     

Preparation, Characterization and Properties of Two New Lanthanide(III)-5-(2-pyridyl)tetrazolate Complexes

Two new mononuclear lanthanide(III) complexes Ln(pytz)3(H2O)3·(H2O)3.5[Ln=Tb(1); Eu(2); Hpytz= 5-(2-pyridyl)tetrazole] were synthesized by reacting Hpytz with the corresponding lanthanide(III) ions and characterized. The single crystal X-ray diffraction analysis reveals that complexes 1 and 2 are isostructural and the lanthanide(III) ions in both complexes 1 and 2 are nine-coordinated, with three oxygen atoms of three coordination water molecules and six nitrogen atoms of three pytz ligands, forming a monocapped square antiprism. Extensive hydrogen bonds exist, resulting in a three-dimensional supramolecular network structure by hydrogen-bonds in both complexes 1 and 2, respectively. Complex 1 exhibits typical green fluorescence of Tb(III) ion and complex 2 red fluorescence of Eu(III) ion, in solid state at room temperature.     

Synthesis and properties of 1-(2-hydroxyethyl)tetrazole

The heterocyclization of monoethanolamine with ethyl orthoformate and sodium azide in acetic acid was studied. It was shown that the reaction proceeds through a step involving the formation of a disubstituted formamidine and leads to the production of 1-(2-hydroxyethyl)tetrazole in high yield. A method for the purification of 1-(2-hydroxyethyl)tetrazole by complexing with cupric chloride was developed, and its physicochemical properties and some chemical transformations were investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1422–1424, October, 1985.     

反相高效液相色谱法测定1-(对偶氮苯)-3-(5-氯-2-吡啶)-三氮烯

采用ZORBAX Ec lipse XDB-C8(4.6 mm i.d.×150 mm,5μm)色谱柱,乙腈流动相,流速0.70 mL.m in-1,检测波长407 nm,建立了测定1-(对偶氮苯)-3-(5-氯-2-吡啶)-三氮烯的反相高效液相色谱法.该方法线性范围0.5-8.0 mg.L-1,相对标准偏差为2.5%(c=5.0 mg.L-1,n=5),回收率在95.7%-105%之间.     

2,6-Bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine as a ligand for efficient actinide(III)/lanthanide(III) separation

The N-donor complexing ligand 2,6-bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine (C5-BPP) was synthesized and screened as an extracting agent selective for trivalent actinide cations over lanthanides. C5-BPP extracts Am(III) from up to 1 mol/L HNO(3) with a separation factor over Eu(III) of approximately 100. Due to its good performance as an extracting agent, the complexation of trivalent actinides and lanthanides with C5-BPP was studied. The solid-state compounds [Ln(C5-BPP)(NO(3))(3)(DMF)] (Ln = Sm(III), Eu(III)) were synthesized, fully characterized, and compared to the solution structure of the Am(III) 1:1 complex [Am(C5-BPP)(NO(3))(3)]. The high stability constant of log β(3) = 14.8 ± 0.4 determined for the Cm(III) 1:3 complex is in line with C5-BPP's high distribution ratios for Am(III) observed in extraction experiments.     

新型1-吡啶基-3,5-二甲基-1-氢吡唑类化合物的合成及晶体结构

以卤代吡啶为起始原料与水合肼反应合成肼基吡啶衍生物中间体,该中间体进一步与2,4-戊二酮关环合成了一类新型1-吡啶基-3,5-二甲基吡唑衍生物。对合成目标化合物进行了质谱、核磁表征。并且采用X射线单晶衍射分析方法进一步测定了目标化合物1-(3,5,6-三氯吡啶-2-基)-3,5-二甲基-1氢吡唑(3f)的晶体结构。     

Synthesis and properties of 2-(2-pyridyl)-1-azaazulene

The title azaazulene 3 was synthesized either by reaction of tropone with N-{(2-pyridyl)acetyl}pyridinium iodide in the presence of ammonium acetate or by palladium-catalyzed cross-coupling between 2-halo-1-azaazulene and 2-substituted pyridine. The compound shows relatively stronger basicity compared with 2,2′-bipyridyl. While 3 showed no emission from the S₁ state but from the S₂ state like azulene does, the protonated species of 3 exhibited emission from the S₁ state. Cationic metal-dependent absorption and emission relating to complexation were also studied.     

Nitrogen-rich 5-(1-methylhydrazinyl)tetrazole and its copper and silver complexes

Nitrogen-rich 5-(1-methylhydrazinyl)tetrazole (1, MHT) was synthesized by using a straightforward method. White plate crystals of 1 were isolated in acetonitrile and crystallized in the monoclinic system P2(1)/c (# 14) (a = 3.8713(18) ?, b = 12.770(6) ?, c = 9.974(5) ?, α = 90°, β = 93.397(6)°, γ = 90°, V = 492.3(4) ?(3), Z = 4). The reactions of Cu(II) and Ag(I) ions in aqueous solution with 1 were investigated and found to form two complexes under mild conditions. The crystal structures of 2 and 3 are discussed with respect to the coordination mode of the MHT anion. Thermal stabilities were determined from differential scanning calorimetry (DSC) combined with thermogravimetric analysis (TGA) tests. Impact sensitivity was determined by BAM standards showing that these MHT salts are insensitive to impact (>40 J) confirmed by UN standards. The energies of combustion of 1-3 were determined using oxygen bomb calorimetry values and were used to obtain the corresponding enthalpies of formation. Combined with these data above, the neutral MHT is an attractive nitrogen-rich ligand for metallic energetic materials. Its copper and silver coordinated complexes are of interest as potential "green" metal energetic materials with high thermal stability as well as low sensitivity to impact and a high molar enthalpy of formation.     

Reagents for new heteroannelation reactions III. 2-(Methylthio)-2-thiazoline

Summary A variety of partly novel tri- and tetracyclic hetero systems were obtained by reaction of heteroaromatic 2-aminoesters with 2-(methylthio)-2-thiazoline, yielding double-annelation of a thiazolo[2,3-b]pyrimido moiety in a one-pot process.On leave from University of Chittagong, Bangladesh