Structure of Cyclic Aryl Thioester Dimer Based on o-Phthaloyl Dichloride and Bis(4-mercaptophenyl) Sulfide

IntroductionTheadvantageofmacrocyclicoligomersasprecursorsforthepreparationofhighperformancepolymersviaring openingpolymerization (ROP)hassparkedmuchinterestintheareaofadvancedthermoplasticcomposites.1 3Andaseriesofcyclicoligomerssuchascarbonates,4 arylesters ,5,6 ethers,7amides8andsulfides9,10 hasbeensuccessfullysynthesized .Recently ,Nishikuboetal.11reportedakindofnovelmacro cyclicoligomerscontainingthioestergroupspreparedbycon densationofbis(4 mercaptophenyl)sulfidewitharomaticaciddichlo…     

Synthesis,Dimer Crystal Structure and Herbicidal Activity of 2-（4-Ethoxybenzoyl）cyclopentane-1,3-dione

The title compound 2-(4-ethoxybenzoyl)cyclopentane-1,3-dione(C14H14O4) was synthesized, and its crystal structure was studied. It crystallized in the triclinic system, space group P1 with a = 8.980(2), b = 9.080(2), c = 15.482(3) , α = 93.49(3), β = 93.84(3), γ = 107.27(3)°, Dc = 1.365 g/cm3, Z = 4, λ = 0.71073, μ(MoKα) = 2.769 mm-1, Mr = 246.25, V = 1198.5(4)3, F(000) = 520, the final R = 0.0559 and wR = 0.1278 for 2301 observed reflections with I 2σ(I). In the crystalline state, the molecular skeleton contains one enol grouping, which is intramolecularly hydrogen bonded to a neighboring keto O atom. Preliminary bioassay result showed that this compound provided 93.8% and 87.2% control of B. campestris and A. retroflexus at post-emergence at 375 g/hm2.     

Synthesis and Crystal Structure of Novel Dimer of Bismuth（Ⅲ） Complex with Dithiotetrahydropyrrolocarbamate： [Bi （S2CNC4H8）2 （NO3） ]2

IntroductionThe chemistry of organotin( ) dithiocarba-mate complexes has been extensively studied due totheir biological activities[1_ 7] .Up to date,a largenumber of transition- metal complexes with dithio-carbamate have been synthesized and structurallycharacterized,including Ni( S2 CNC4H8O) 2 [8] ,Cu( S2 CNC4H8) 2 [9] ,Zn2 ( S2 CNC4H8) 4 [9] andFe( S2 CNC4H8O) 2 ( DMF) [10 ] . However,the chem-istry of the main- group metal complexes withdithiocarbamate has been scarcely studie…     

Synthesis and Crystal Structure of 3,4—Bis（azidoacetamino）furazan

1INTRODUCTIONDuringthepastthreedecades,1,2,5-oxadiazole(furazan)hasbeenstudiedintheN.D.ZelinskyInstituteofOrganicChemistry[1,2],anditwasfoundthatthearomaticityoffurazanringusuallyincreasesthethermalstabilityofitsderivativesandtheplanarityoftheringprovidesthemwithhighdensity.TheweaknessoftheNObondsinfurazanwassuggestedbyananalysisofitsmass-spectrum[3].Itagreeswiththeresultsoftheresonanceformsoffurazan,whichiscalculatedbySaegebrath[4].Thereby,whenthechloroacetaminogroupwasintroducedintot…     

Syntheses of multicyclic poly(ether sulfone)s from 5,5′,6,6′‐tetrahydroxy‐3,3,3′,3′‐tetramethyl spirobisindane and 4,4′‐bis(4‐chlorophenyl) sulfones

5,5′,6,6′‐Tetrahydroxy‐3,3,3′,3′‐tetramethyl spirobisindane (TTSBI) was polycondensed with 4,4′‐dichlorodiphenyl sulfone (DCDPS) or with 4,4′‐bis(4‐chlorophenyl sulfonyl) biphenyl (BCSBP) in DMSO. Concentration and feed ratio were optimized to avoid gelation and to obtain a maximum yield of multicyclic polyethers free of functional groups. Regardless of these reaction conditions, only low fractions of perfect multicycles were obtained from DCDPS apparently due to steric hindrance of ring closure. Under the same conditions high fractions of perfect multicycles were achieved with the longer and more flexible DCSBP. The reaction products were characterized by MALDI‐TOF mass spectrometry, ¹H‐NMR spectroscopy viscosity, and DSC measurements. Relatively low glass transition temperatures (T_gs ≈ 160–175 °C) were found. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3732–3739, 2008     

MALDI-TOF质谱表征聚芳醚酮环状低聚物及其组分分布

应用介质辅助激光解吸离子化飞行时间质谱(MALDI-TOFMS),以二羟基苯甲酸为介质、N₂(337nm)为激光源,对两种聚芳醚酮环状低聚物的结构进行了确认,研究了环状低聚物不同聚合度组分的分布规律,并且与GPC质量分析法作了比较,实验结果表明,MALDI-TQF质谱是分析环状低聚物的准确、快速的工具之一.     

A pitfall of using 2‐[(2E)‐3‐(4‐tert‐butylphenyl)‐2‐methylprop‐2‐enylidene]malononitrile as a matrix in MALDI TOF MS: chemical adduction of matrix to analyte amino groups

2‐[(2E)‐3‐(4‐tert‐Butylphenyl)‐2‐methylprop‐2‐enylidene]malononitrile (DCTB) has been considered as an excellent matrix for matrix‐assisted laser desorption/ionization (MALDI) of many types of synthetic compounds. However, it might provide troublesome results for compounds containing aliphatic primary or secondary amino groups. For these compounds, strong extra ion peaks with a mass difference of 184.1 Da were usually observed, which might falsely indicate the presence of some unknown impurities that were not detected by other matrices. On the basis of the possible mechanisms proposed, these extra ions are the products of nucleophilic reactions between analyte amino groups and DCTB molecules or radical cations. In these reactions, an amino group replaces the dicyanomethylene group of DCTB forming a matrix adduct via a ? C?N‐bond. An aliphatic primary amine could react easily with DCTB and the reaction could start once they are mixed in a MALDI solution. For an aliphatic secondary amine, on the other hand, the reaction most likely occurs in the gas phase. Protonation of amino groups by adding acid seems to be a useful way to stop DCTB adduction for compounds with one single amino group, but not for compounds with multiple amino groups. Unlike aliphatic primary or secondary amines, aliphatic tertiary amines and aromatic amines do not yield DCTB adducts. This is because tertiary amines do not have the required transferrable H‐(N) atom to form an extra ? C?N‐bond, while aromatic amines are not sufficiently nucleophilic to attack DCTB. In view of the possible matrix adduction, care should be taken in MALDI time‐of‐flight mass spectrometry (TOF MS) when DCTB is used as the matrix for compounds containing amino group(s). Copyright © 2010 John Wiley & Sons, Ltd.     

Multicyclic polyethers derived from 1,1,1‐tris(4‐hydroxyphenyl)ethane and 2,6‐dihalopyridines

Poly(pyridine ether)s were prepared in two ways: the polycondensation of silylated 1,1,1‐tris(4‐hydroxyphenyl)ethane (THPE) with 2,6‐difluoropyridine (method A) and the polycondensation of free THPE with 2,6‐dichloropyridine (method B). With method A, the THPE/difluoropyridine feed ratio was varied from 1.0:1.0 to 1.0:1.6. Cycles, bicycles, and multicycles were the main reaction products, and crosslinking was never observed. When ideal stoichiometry was used exclusively, multicycles free of functional groups were obtained. These multicycles were detectable in matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectra up to B₃₈C₇₆ with a mass of approximately 32,000 Da. With method B, the reaction conditions were varied at a fixed feed ratio to achieve an optimum for the preparation of multicyclic polyethers, but because of the lower reactivity of 2,6‐dichloropyridine, a quantitative conversion was not achieved. The reaction products were characterized with MALDI‐TOF mass spectrometry, viscosity measurements, and size exclusion chromatography. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5725–5735, 2004     

Structure and Photosynthetic Mimicking of Bis（2,6—bis（benzimidazol—2—yl）pyridine）manganese（Ⅱ）

Mn(bzimpy)2(1)[bzimpy=2,6-bis(benzimidazol-2-yl)pyridine],a mononuclear manganese(Ⅱ）complex,was synthesized by the reaction of Mn(OOCMe)2 with bzimpy in absolute ethanol.The complex was structurally characterized by elemental analysis,cyclic voltammetry,and X-ray crystallography.In the complex,the manganese-nitrogen distances were different,and the geometry and the metal ion environment showed the distortion.The cyclic voltammetric measurements have been performed to assess its redox characteristics.The presence of oxidation wave at 0.62V and 0.081V vs.SCE or 0.8V and 1.0v vs.NHE suggested that this complex could catalyze the oxidation of water,therefore,simulate the water-oxidizing complex(WOC) of photosystem Ⅱ (PS Ⅱ).The measurements of photoreduction of 2,6-dichlorophenolindophenol (DCPIP),and oxygen evolution in the manganess-depleted and the comples 1-reconstituted PS Ⅱ preparations just support our conjecture.     

双（取代环戊二烯基）二氯化钛的晶体结构分析

报道了双（１－正戊基环己基茂）二氯化钛［（η５－Ｃ５Ｈ４Ｃ（ＣＨ２）５（Ｃ５Ｈ１１－ｎ］２ＴｉＣｌ２（Ｉ）及双（１－甲基－１－（α－噻吩基）乙基环戊二烯基）二氯化钛［η￣５－Ｃ５Ｈ４Ｃ（ＣＨ３）＿２－］２ＴｉＣｌ２（Ⅱ）的晶体结构和分子结构。二者均系单斜晶系，（Ｉ）的空间群为Ｐ２／ｎ，晶胞参数ａ＝１４．１８０（２），ｂ＝６．５６２（１），ｃ＝１７．０４６（３），β＝９９．６３（１）°，Ｚ＝２，Ｖ＝１５６３．８，Ｄｘ＝１．１８８ｇ／ｃｍ３，Ｆ（０００）＝５９６，Ｍｒ＝５５３．５６，λ＝０．７１０７３μ＝４．５９ｃｍ－１，Ｒ＝０．０５８，Ｒｗ＝０．０６６；（１）的空间群为Ｃ２／ｃ，晶胞参数ａ＝２５．７１３（１），ｂ＝６．６１７（１），ｃ＝１３．５９１（１），β＝９２．７８（２）°，Ｚ＝４，Ｖ＝２３０９．８，Ｄｘ＝１．４３０ｇ／ｃｍ３，Ｍｒ＝４９７．４１，λ＝０．７１０７３，μ＝７．８２２ｃｍ－１，Ｆ（０００）＝１０３２，Ｒ＝０．０５５，Ｒｗ＝０．０７２。茂环上取代基对茂环金属化合物的结构产生较大影响，空间阻碍的增大使得取代基与茂环相连Ｃ－Ｃ单键增长。     

A New Route to N‐Aryl 2‐Alkenamides,N‐Allyl N‐Aryl 2‐Alkenamides,and N‐Aryl α,β‐Unsaturated γ‐Lactams from N‐Aryl 3‐(Phenylsulfonyl)propanamides

A series of N‐aryl 2‐alkenamides were produced efficiently by treating N‐aryl 3‐(phenylsulfonyl)‐propanamides with potassium tert‐butoxide in THF at 0°C. With out isolation, it was further treated with an additional equivalent of potassium tert‐butoxide and allyl bromide to give N‐allyl N‐aryl 2‐alkenamides in one pot in good yields. Followed by a ring‐closing metathesis reaction, these N‐allyl N‐aryl 2‐alkenamides were respectively converted into corresponding N‐aryl α,β‐unsaturated γ‐lactams in moderate yields.     

Crystallographic report: Bis(4‐nitrobenzoato)bis(pyridine)zinc(II)

The molecular structure of [Zn(O₂CC₆H₄NO₂‐p)₂(pyridine)₂] exhibits a distorted N₂O₂ tetrahedral geometry around the zinc atom owing to the presence of monodentate p‐nitrobenzoate ligands; the molecule has twofold symmetry. Copyright © 2004 John Wiley & Sons, Ltd.     

Crystallographic report: Bis[3‐(tri‐p‐tolyl)germyl‐3‐(o‐tolyl)‐propionato]dibutyltin(IV)

The crystal structure of [(p‐CH₃C₆H₄)₃GeCH(o‐CH₃C₆H₄)CH₂CO₂]₂Sn(C₄H₉)₂ consists of a monomer with the atoms of tin and germanium both occupying tetrahedral geometries. However, the tin atom is distorted towards a skew trapezoidal bipyramid geometry as a result of weakly chelating carboxylate ligands. Copyright © 2003 John Wiley & Sons, Ltd.