Unusual dirhenium complexes containing the bis[2-(diphenylphosphino)phenyl]ether ligand including a terephthalate-bridged tetrarhenium compound

The synthesis, structures and reactivity of unsymmetrical multiply-bonded dirhenium(IV,II) and dirhenium(III,II) complexes that contain the bis[2-(diphenylphosphino)phenyl]ether ligand (L¹) are described, including the isolation and structural characterization of the novel terephthalate-bridged tetrarhenium complex [Re₂Cl₄(η³-L¹)]₂(μ-O₂CC₆H₄CO₂) in which there is weak electronic coupling between the pairs of dirhenium centers.     

Synthesis and Characterization of Poly[bis(3-aminophenyl) diselenide] and Poly[bis(3-aminophenyl) diselenide-co-aniline]

Summary Bis(m-aminophenyl)diselenide was synthesized by diazotation of m-nitroaniline followed by incorporation of potassium selenium cyanate, and the reduction of the nitro groups by addition of tin and concentrated HCl. This dihydrochloride monomer was polymerised using ammonium persulphate in 0.25 M HCl as oxidizing agent. Copolymers of aniline with bis(m-aminophenyl)diselenide were prepared by oxidation of diselenide and aniline mixtures, at several mole ratios of aniline in the feed (f₁), with the same oxidizing agent. In the all the range of polymers analysed there are more diselenide comonomer units than aniline units. The polymer and copolymers were characterized by FTIR, elemental analysis, thermal stability and electrical conductivity, showing a high thermal stability, with a weight loss of 10% at 400 °C and there is an important effect of groups diselenide on the electrical properties, because conductivities are highly modified when the substitution is in m-position in the aniline ring. Therefore, it is necessary to add a high mole ratio of aniline in the feed to obtain copolymers with conductivities within the semi-conduction range.     

Synthesis and characterization of novel polyurethanes based on 4,4′-[1,4-phenylenedi-diazene-2,1-diyl]bis(2-carboxyphenol) and 4,4′-[1,4-phenylenedi-diazene-2,1-diyl]bis(2-chlorophenol) hard segments

Eight novel polyurethanes (PUs) based on 4,4′-[1,4-phenylenedi-diazene-2,1-diyl]bis(2-carboxyphenol) and 4,4′-[1,4-phenylenedi-diazene-2,1-diyl]bis(2-chloro- phenol) as hard segments with four diisocyanates viz., 4,4′-diphenyl-methane diisocyanate, toluene 2,4-diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate were prepared. Structural and thermal characterization of the segmented PUs were determined by FT-IR, UV spectrophotometry, fluoroscence spectroscopy, ¹H NMR, ¹³C NMR spectroscopy and DTA/TGA analysis. All the PUs contain domains of semi-crystalline and amorphous structures, as indicated by X-ray diffraction. PUs were soluble in polar aprotic solvents like N-methyl-2-pyrrolidone (NMP), dimethyl formamide (DMF) and dimethylsulfoxide (DMSO).     

Base induced [1,2]- and [3,2]-rearrangements of N-(2-Thenyl)-N-benzyldimethylammonium ion

The title compound 4 underwent Sommelet and Stevens rearrangements induced by a number of bases. Ionization of the thenyl methylene group of 4 to the corresponding ylid 10 was the prevalent process, yielding subsequently N-[2-(2′-thienyl)-2-phenethyl]dimethylamine 12 and N-[α-(o-tolyl)-2-thenyl]-dimethylamine 13 . The strong trend of the 2-thenyl ylids to produce large relative amounts of the Sommelet amine was confirmed. Minor products are N-[2-(2′-thienyl)-1-phenethyl]dimethylamine 15 and N-[α-phenyl-2-(3-methylthienyl)]dimethylamine 16 derived from the benzyl ylid 11 .     

苯并[1,2-d:5,4-d']二((口恶)唑)-2,6-二硫醇的合成及表征

苯并(口恶)唑类化合物是一类重要的杂环化合物,不仅在生物、医药等方面有着广泛应用,而且在光学材料、高性能复合材料等诸多领域也显现出独特的性能.以间苯二酚为原料,经过酯化反应和Fries重排、肟化反应、Beckmann重排和水解反应合成4,6-二氨基间苯二酚盐酸盐(DAR· HCl).然后以4,6-二氨基间苯二酚盐酸盐和二硫化碳为原料合成标题化合物,并且优化了过程的工艺条件,过程的总收率为37.3％.利用红外光谱、核磁共振谱、质谱和元素分析等分析手段对中间产物及目标化合物进行了表征.     

Fabrication of a novel holmium(III) PVC membrane sensor based on 4-chloro-1,2-bis(2-pyridinecarboxamido)benzene as a neutral ionophore

This paper introduces the development of an original PVC membrane electrode, based on 4-chloro-1,2-bis(2-pyridinecarboxamido)benzene (CBPB) as a suitable carrier for the Ho³⁺ ion. The electrode presents a Nernstian slope of 19.7 ± 0.3 mV per decade for the Ho³⁺ ions across a broad working concentration range from 1.0 × 10⁻⁶ to 1.0 × 10⁻² M. The lower detection limit was 8.5 × 10⁻⁷ M in the pH range 2.7–9.8, while the response time was rapid (<15 s). Therefore, this potentiometric sensor displayed good selectivity for a number of cations such as alkali, alkaline earth, transition and heavy metal ions. The practical applicability of the electrode was demonstrated by its use as an indicator electrode in the potentiometric titration of Ho³⁺ ions with EDTA and in the determination of F^- in mouth wash samples.     

Electrochemical copolymerization and stability of crosslinked bis[1,2‐(pyrrol)ethoxy]ethane with pyrrole

The copolymers, pyrrole‐co‐bis[1,2‐(pyrrol)ethoxy]ethane (PEE), were produced by electropolymerization in acetonitrile (containing 0.1 mol L⁻¹ lithium perchlorate). The properties and morphology of these polymers were investigated by cyclic voltammetry, UV–vis absorption spectra and scanning electron microscopy (SEM), respectively. The results exhibit that the cyclic voltammograms and rates of electropolymerization of the prepared copolymers were significantly affected by PEE concentration in water and acetonitrile solution. Higher applied potential was required for the polymerization with decreasing the ratio of pyrrole/PEE. This was ascribed to the steric hindrance of high concentration of N‐substituted groups. The SEM images of the poly(pyrrole‐co‐PEE) and PPEE films show more compact and more smooth morphology compared with that of PPy and cyclic voltammogram of the poly(pyrrole‐co‐PEE) films, which display good electrochemical stability in the mixed solution, indicating that the modification of crosslinked structure was effective for the stabilization of the redox cycles. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Synthesis and Characterization of Poly[bis(ethyl salicylate)phosphazenes] and Poly[bis(ethyl salicylate diethylamino)phosphazenes] and Their Hydrolytic Degradation

The polydichlorophosphazenes were synthesized from hexachlorocyclotriphosphazenes by ring opening polymerization in the presence of AlCl₃ as a catalyst. Poly[bis(ethyl salicylate)phosphazenes] (PESP) and poly[bis(ethyl salicylate diethylamino)phosphazenes] (PESDEAP) were synthesized via macromolecular substitution reactions using ethyl salicylate and (or) diethylamine as side groups. The synthesis results were proved by nuclear magnetic resonance (¹H NMR, and ³¹P NMR) and gel permeation chromatography. In addition, the hydrolytic degradation of PESP and PESDEAP was investigated at constant temperature in neutral medium.     

1,2-二(3-羰基苯并[d]异噻唑-2(3H)-基)乙烷-1,2-二酮合成及其抑菌活性的测定

以邻氯苯腈为原料合成2-甲硫基苯甲腈,与磺酰氯在氯苯中反应,制得1,2-苯并异噻唑啉-3-酮(BIT),最后与草酰氯反应,制得目标产物1,2-二(3-羰基苯并[d]异噻唑-2(3H)-基)乙烷-1,2-二酮,其结构用红外光谱和1H NMR光谱进行了确证,并进行了抑菌活性的测试,结果表明,该化合物最低抑菌浓度达到8μg/mL。     

Dehydrogenative oligomerization reactivity of transition metal sulfides derived from their tris or bis(o-aminobenzenethiolato)metal complexes

Several tris or bis(o-aminobenzenethiolato)metal complexes, where metals include ruthenium, rhodium, rhenium, molybdenum, platinum, and palladium, were synthesized. They were used as precursors to active metal sulfide catalysts for dehydrogenative oligomerization of 1,2,3,4-tetrahydroquinoline (THQ). The conversion of metal complex precursors to the corresponding metal sulfides was carried outin situ in the THQ solution at 210–270 °C. These metal sulfides polymerized THQ to quinoline oligomers in 71–95% yield. We also observed a periodic trend on the activity of these catalysts showing a maximum oligomer yield with ruthenium sulfide.     

Unsaturated polyesters based on bis(2-hydroxyethyl)terephthalate

A series of unsaturated polyesters based on bis(2-hydroxyethyl)terephthalate, ethylene glycol, propylene glycol, diethylene glycol, maleic anhydride and styrene were prepared. Properties of these castings were investigated and compared with those analogues based on dimethyl terephthalate or polyester oligomers formed by depolymerization of poly(ethylene terephthalate). It is found that properties of castings based on bis(2-hydroxyethyl)terephthalate are superior to those based on polyester oligomer. When compared with those based on dimethyl phthalate, the castings have higher hardness and heat distortion temperature, but lower tensile strength and elongation; other properties are very similar.     

Synthesis of 2-( imidazo [1,2-a] pyridin-3-yl) acetic acid

研究了一种用于治疗骨质疏松症药物的关键中间体米诺膦酸的制备方法.实验以二乙氧基膦酰乙酸乙酯和2,2-二甲氧基乙醛为起始原料,经维蒂希-霍纳反应、水解、环合、水解4步制备得到标题化合物.其熔点与1HNMR和文献报道的结果一致,总收率87.5％(以2-氨基吡啶计).该方法克服了文献报道的工艺缺陷,与现有技术相比,后处理更简单,更适合工业化生产.     

Synthesis,characterization and crystal structure of bis(acetylacetonato)dimethanolnickel(II): [Ni(acac)2(MeOH)2]

Bis(acetylacetonato)dimethanolnickel(II) was isolated as turquoise needle-like crystals by recrystallization of bis(acetylacetonato)nickel(II) from methanol solution and fully characterized by ¹H and ¹³C NMR, FT-IR spectroscopy, and single crystal X-ray diffraction. The X-ray structure analysis gives essentially a triclinic unit cell of bis(acetylacetonato)dimethanolnickel(II) containing one centrosymmetric molecule of the formula Ni[(O₂C₅H₇)₂(OHCH₃)₂]. The Ni(II) ion is located at the inversion centre of a tetragonally distorted octahedral coordination sphere. The equatorial plane of the tetragonally distorted octahedral coordination sphere includes four O-donor atoms of two acetylacetonato ligands and the axial positions are occupied by two oxygen atoms of two methanol ligands.     

N,N’-二硝基-N,N’-二(3-([1,2,3]-三唑并[4,5-c]呋咱-4,5-内盐-5-基)呋咱-4-基)二氨基甲烷的合成与表征

以二氨基呋咱(DAF)为起始原料,经Caro's acid氧化、锌粉还原、环化、缩合和硝化五步反应得到N,N’-二硝基-N,N ’-二(3-([1,2,3]-三唑并[4,5-c]呋咱-4,5-内盐-5-基)呋咱-4-基)二氨基甲烷(MNOTO),总收率为32.7％(以DAF计).用元素分析、核磁共振、红外光谱等进行了结构表征.用浓硝酸和醋酐作为硝化体系硝化N,N’-二(3-([1,2,3]-三唑并[4,5-c]呋咱-4,5-内盐-5-基)呋咱-4-基)二氨基甲烷(MAOTO),考察了反应温度、反应时间以及浓硝酸与醋酐摩尔比对反应收率的影响,硝化体系中硝酸和醋酐的最佳摩尔比为1.5∶1,反应温度15～20℃,反应时间为5h.     

Isomerism in bis(phenylselenolato)bis(triphenylphosphine)platinum(II): the crystal and molecular structures of cis- and trans-[Pt(SePh)2(PPh3)2]

The reaction of cis-[PtCl₂(PPh₃)₂] and NaSePh in benzene produces a mixture of cis- and trans-isomers of the monomeric platinum complex [Pt(SePh)₂(PPh₃)₂]. The low-temperature X-ray structures of both isomers are reported. The structure of cis-[Pt(SePh)₂(PPh₃)₂] is the first crystallographic characterized cis-isomer of mononuclear platinum(II) complex containing only non-chelating organoselenolato and phosphine ligands.     

Synthesis and Characterization of Poly[bis(resorcinol monobenzoate) phosphazenes] and Poly[bis(resorcinol monobenzoate diethylamino) phosphazenes] and Their Self Assembly Behaviors

Poly[bis(resorcinol monobenzoate)phosphazenes] (PRMBP) and poly[bis(resorcinol monoben- zoate diethylamino)phosphazenes] (PRMBDEAP) were synthesized in two steps. In the first step, polydichlorophosphazenes (PDCP) were synthesized from hexachlorocyclotriphosphazenes (HCCP) via ring opening polymerization in the presence of AlCl₃ as a catalyst. In the second step, the chlorine atoms in PDCP were replaced with resorcinol monobenzoate and (or) diethylamine in a macromolecular substitution reaction. The structures of the polymers were elucidated by ¹H NMR, ³¹P NMR, and GPC. In addition, the self assembly behaviors of PRMBP and PRMBDEAP were investigated in different solvent using optical microscopy and SEM techniques. The SEM images showed that PRMBDEAP self assembled into star-like dendrimers comprising of open ended tubular arms.     

水相合成双-[γ-（三乙氧基硅）丙基]-二硫化物

以γ-氯丙基三乙氧基硅烷(简称γ2)、硫氢化钠、硫为原料,通过加入缓冲剂控制反应体系的pH以抑制γ2的水解,同时运用相转移催化技术,在水相中合成了双-[γ-(三乙氧基硅)丙基]二硫化物(简称Si-75)。主要考察了n(NaHS)∶n(S)、n(γ2)∶n(Na2Sx)、n(Na2CO3)∶n(NaHS)、反应温度、相转移催化剂用量等对合成工艺的影响,最终制得的Si-75外观呈浅黄色,产率为95.4%,w(S)=13.5%。     

Facile synthesis and characterization of novel bis(2-S-alkylpyridines) and bis(3-aminothieno[2,3-b]pyridines) incorporating 1,3-diarylpyrazole moiety

3-(4-Hydroxyphenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde (1) is condensed with acetophenone to afford the corresponding unsaturated carbonyl compound 4 whose potassium salt is reacted with 1,4-dibromobutane to afford the bis-unsaturated carbonyl compound 3. Both carbonyl compounds 3 and 4 are reacted with 2-cyanoethanethioamide, through Michael addition reaction followed by cyclocondensation, to prepare the starting materials bis(pyridine-2(1H)-thione) derivative 5 and pyridine-2(1H)-thione derivative 8. Two synthetic routes to synthesize the target materials 7 and 14 are described to get the most efficient method for preparation and maximum yield%. The first route came from the direct alkylation of the bis(pyridine-2(1H)-thione) derivative 5 using iodomethane (6a) and benzyl chloride (6b) to afford the corresponding bis(2-S-alkylpyridine) derivatives 7a,b. The reaction of 5 with halo-containing compounds 10a–d to synthesize the target materials bis(3-aminothieno[2,3-b]pyridine) derivatives 14a–d failed under various reaction conditions. The second route involves the reaction of pyridine-2(1H)-thione derivative 8 with 6a,b and 10a–d to afford the corresponding 2-S-alkylpyridine derivatives 9a,b and 3-aminothieno[2,3-b]pyridine derivatives 13a–d, through the formation of 2-S-alkylpyridine derivatives 12a–d followed by a Thrope-Ziegler reaction, whose potassium salts reacted with 1,4-dibromobutane to afford the corresponding target materials 7a,b and 14a–d, respectively. The structures of target molecules were elucidated using elemental analyses and spectral data.