选择性接聚乙烯醇枝聚醚氨酯的合成及其血液相容性

合成了α－甲基，ω－（２，３－环氧丙基）－聚乙二醇醚（Ⅱ）．经水解得到悬挂聚乙二醇（ＰＥＧ）枝的丙二醇－２，３（Ⅲ）．用二元醇（Ⅲ）为扩链剂制得了在硬链段上接有ＰＥＧ枝的聚醚氨酯（Ｈ－ＰＥＵ）．以四氢呋喃与少量大分子单体（Ⅱ）进行正离子开环共聚合制得每个链接有约１．３个ＰＥＧ枝的聚丁二醇（Ⅳ），用以合成了在软链段上接有ＰＥＧ枝的聚醚氨酯（Ｓ－ＰＥＵ）．ＥＳＣＡ及抗凝血性研究结果表明，不同位置接枝的ＰＥＵ，其表面都有明显的聚醚链段富集．Ｓ－ＰＥＵ抗凝血复钙时间只比未接枝者增长约２０％，而Ｈ－ＰＥＵ则增约一倍，比Ｓ－ＰＥＵ增约６０％．随ＰＥＧ最增大，复钙时间增长．     

Synthesis of new pyrazoles,oxadiazoles, triazoles,pyrrolotriazines, and pyrrolotriazepines as potential cytotoxic agents

4-Oxo-4-phenylbutanehydrazide (1) reacted with many active methylene reagents such as acetylacetone, diethylmalonate, ethylacetoacetate, ethylcyanoacetate, benzoyl-acetonitrile, and malononitrile under neat conditions to afford the corresponding pyrazoles (2–7) , also, treatment of butanehydrazide (1) with electrophilic reagents as triethylorthoformate, dimethylformamide-dimethylacetal, acetic anhydride, and carbon disulfide to give 1,3,4-oxadiazoles (8,10,11) and N′-acetyl-butanehydrazide (9) . Reacted of butanehydrazide (1) with potassium thiocyanate gave 1,2,4-triazoles (12) . Similarly, treatment of (1) with chloroacetamide gave 1,2,4-triazinones (13) . The pyrrolotriazinones (14) was obtained by cyclization of (13) . Also, butanehydrazide ( 1 ) was utilized as a starting material for the synthesized of new Schiff bases as N′-(4-sub-benzylidene)-phenylbutane-hydrazide (15a-c) , which are used as an initiative to prepare new compounds such as 1,2,4-triazepinones (16a-c) , pyrrolotriazepinones (17a-c) , 1,2,4-triazines (18a-c) , and pyrrolotriazines (19a-c) by reacted of (15a-c) with each chloroacetamide or formamide. The chemical structure of the newly prepared compounds was determined through the spectrum data, including IR, NMR, and MS. The prepared compounds were tested for their in vitro antitumor activities. The compounds 17a-c , 16a-c , and 19a-c displayed activity against several types of cancer cell lines.     

Enantioseparation of the anticoagulant drug phenprocoumon in capillary electrophoresis with UV and laser-induced fluorescence detection and application of the method to urine samples

The enantioseparation of phenprocoumon (PhC) in capillary electrophoresis (CE) has been studied using various cyclodextrins (CDs) such as native alpha, beta and gamma-CD and several neutral and randomly, as well as selectively substituted charged CD derivatives. Reversal of the enantiomer migration order was observed when using heptakis(2,3,6-tri-O-methyl (TM)-beta-CD as a chiral selector compared to all other CDs used. The detection of PhC was performed using either UV or laser-induced fluorescence (LIF) detection. The limit of detection (LOD) observed with LIF detection was ca. 20 times lower compared to UV. The method has been applied to the analysis of urine samples of the patient under treatment with PhC in combination with other drugs such as ramipril, hydrochlorothiazide, and nifedipine.     

Electronic structures of low-lying Bu excited states in trans-oligoenes: Pariser-Parr-Pople and ab initio calculations

Two lowest-lying excited singlets with B(u) symmetry of all-trans-oligoenes, the well-known ionic 1(1)B(u)(+) state as well as the "hidden" ionic-covalent-mixed 1(1)B(u)(-) state, are calculated within both the Pariser-Parr-Pople (PPP) model at full configuration interaction (FCI) level and ab initio methods. The vertical excitation energies as well as wavefunctions from PPP-FCI calculations are found to be in good agreement with those from high-level multi-reference methods, such as multi-reference complete active space self-consistent field (CASSCF) with second order perturbative corrections (CASPT2), multi-reference M?ller-Plesset perturbation theory (MRMP), and complete active space valence bond theory (CASVB). The oscillator strengths from PPP calculation are in good agreement with spectroscopy experiments. The relatively small oscillator strength of 1(1)B(u)(-) is due to the approximate electron-hole symmetry of this state. In addition, the bond lengths in both states are found to show remarkable relativity with the bond orders calculated with ground state geometries, which suggests a possible strategy for initial guess in geometry optimization of excited states.     

Combustion synthesis and electrochemical properties of the small hydrofullerene C50H10

The hydrofullerene C(50)H(10) is synthesized by low-pressure benzene-oxygen diffusion combustion. The structure of C(50)H(10) is identified through NMR, mass spectrometry, and IR and Raman spectroscopy as a D(5h) symmetric closed-cage molecule with five pairs of fused pentagons stabilized by ten hydrogen atoms. UV/Vis and fluorescence spectrometric analyses disclose its optical properties as comparable with those of its chloride cousin (C(50)Cl(10)). Cyclic and square-wave voltammograms reveal that the first reduction potential of C(50)H(10) is more negative than that of C(50)Cl(10) as well as C(60), with implications for the utilization of C(50)H(10) as a promising electron acceptor for photovoltaic applications.     

Reversible carbon-carbon bond formation between 1,3-dienes and aldehyde or ketone on nickel(0)

The reversible oxidative cyclization of dienes and aldehydes with nickel(0) proceeded to give eta(3):eta(1)-allylalkoxynickel complexes. The treatment of these complexes with carbon monoxide led to the formation of the corresponding lactone and/or the regeneration of a butadiene and an aldehyde concomitant with the formation of Ni(CO)(3)(PCy(3)). The scission of the nickel-oxygen bond of the allylalkoxy complexes with ZnMe(2) leading to eta(3)-allyl(methyl)nickel was very efficient to suppress the reverse reaction of the oxidative cyclization. The methylated eta(3)-allylnickel compound underwent the reductive elimination. The carbonylative coupling reaction of the eta(3)-allyl(methyl)nickel proceeded as well under a carbon monoxide atmosphere. Similarly, the addition of Me(3)SiCl to eta(3):eta(1)-allylalkoxynickel complexes was also efficient for the inhibition of the reverse reaction. The resulting eta(3)-1-siloxyethylallylnickel complex was treated with carbon monoxides followed by the addition of MeOH to give the expected hydroxyester. This method is efficient as well even for the eta(3):eta(1)-allyl(alkoxy)nickel complex containing acetone as a component, which was so prone to undergo the reverse reaction hampering its isolation. The isolation of the eta(3):eta(1)-allylalkoxynickel complex containing ketone as a component was made easier by the use of heavier butadiene and ketone, such as 2,3-dibenzyl-1,3-butadiene and benzophenone or by the use of cyclobutanone. The reaction with styrene oxide gave the eta(3):eta(1)-allylalkoxynickel containing phenylacetoaldehyde, an isomer of styrene oxide.     

Direct enantiomeric TLC resolution of dl-penicillamine using (R)-mandelic acid and l-tartaric acid as chiral impregnating reagents and as chiral mobile phase additive

DL-Penicillamine has been resolved into its enantiomers by normal-phase TLC using L-tartaric acid as chiral impregnating reagent as well as chiral mobile phase additive, while (R)-mandelic acid has been found to be successful as a chiral impregnating reagent. The solvent system acetonitrile-methanol-water (5:1:1, v/v) was found to be successful when L-tartaric acid was used as impregnating agent while the solvent combination acetonitrile-methanol-(0.5% l-tartaric acid in water, pH 5)-glacial acetic acid (7:1:1.1:0.7, v/v) was successful as mobile phase as it contained L-tartaric acid as the chiral additive. (R)-mandelic acid was successful as chiral impregnating reagent with ethyl acetate-methanol-water (3:1:1, v/v), as the mobile phase. The effects of concentration of chiral selectors, temperature and pH were examined on enantiomeric resolution. The spots were detected with iodine vapors and the detection limits were found to be 0.12 microg for each enantiomer of penicillamine with L-tartaric acid, under both the conditions, and 0.11 microg with (R)-mandelic acid.     

Facile coupling of propargylic, allylic and benzylic alcohols with allylsilane and alkynylsilane, and their deoxygenation with Et(3)SiH, catalyzed by Bi(OTf)(3) in [BMIM][BF(4)] ionic liquid (IL), with recycling and reuse of the IL

Allyltrimethylsilane (allyl-TMS) reacts with propargylic alcohols in the presence of 10% Bi(OTf)(3) in [BMIM][BF(4)] solvent to furnish the corresponding 1,5-enynes in respectable isolated yields (87-93%) at room temperature. The utility of Bi(OTf)(3) as a superior catalyst was demonstrated in a survey study on coupling of allyl-TMS with employing several metallic triflates (Bi, Ln, Al, Yb) as well as, B(C(6)F(5))(3), Zn(NTf(2))(2) and Bi(NO(3))(3)·5H(2)O. Coupling of cyclopropyl substituted propargylic alcohol with allyl-TMS gave the skeletally intact 1,5-enyne and a ring opened derivative as a mixture. Coupling of propargylic/allylic alcohol with allyl-TMS resulted in allylation at both benzylic (2 isomers) and propargylic positions, as major and minor products respectively. The scope of this methodology for allylation of a series of allylic and benzylic alcohols was explored. Chemoselective reduction of a host of propargylic, propagylic/allylic, bis-allylic, allylic, and benzylic alcohols with Et(3)SiH was achieved in high yields with short reaction times. The same approach was successfully applied to couple representative propargylic and allylic alcohols with 1-phenyl-2-trimethylsilylacetylene. The recovery and reuse of the ionic liquid (IL) was gauged in a case study with minimal decrease in isolated yields after six cycles.     

Diazaborolyl-boryl push-pull systems with ethynylene-arylene bridges as 'turn-on' fluoride sensors

Two linear π-conjugated systems with 1,3-diethyl-1,3,2-benzodiazaborolyl [C(6)H(4)(NEt)(2)B-] as a donor group and dimesitylboryl (-BMes(2)) as acceptor were synthesised with -ethynylene-phenylene- (-C[triple bond, length as m-dash]C-1,4-C(6)H(4)-, 3) and -ethynylene-thiophene- (-C[triple bond, length as m-dash]C-2,5-C(4)H(2)S-12) bridges between the boron atoms. An assembly (20) consisting of two diazaborolyl-ethynylene-phenylene-boryl units, [C(6)H(4)(NCy)(N')B-C[triple bond, length as m-dash]C-1,4-C(6)H(4)-BMes(2)] joined via a 1,4-phenylene unit at the nitrogen atoms (N') of the diazaborolyl units was also synthesised. The three push-pull systems, 3, 12 and 20, form salts on fluoride addition with the BMes(2) groups converted into (BMes(2)F)(-) anions. The molecular structures of 3, 12 and (NBu(4))(12·F) were elucidated by X-ray diffraction analyses. The borylated systems 3, 12 and 20 show intense blue luminescence in cyclohexane with quantum yields (Φ(fl)) of 0.99, 0.44 and 0.94, respectively, but weak blue-green luminescence in tetrahydrofuran (Φ(fl) = 0.02-0.05). The charge transfer nature of these transitions is supported by TD-DFT computations with the CAM-B3LYP functional. Addition of tetrabutylammonium fluoride to tetrahydrofuran solutions of 3 and 20 resulted in strong violet-blue luminescence with emission intensities up to 46 times more than the emission intensities observed prior to fluoride addition. Compounds 3 and 20 are demonstrated here as remarkable 'turn-on' fluoride sensors in tetrahydrofuran solutions.     

Electrochemical studies on poly(vinylidene fluoride-hexafluoropropylene) membranes prepared by phase inversion method

The copolymer membranes, poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) were prepared by phase inversion method using poly(ethylene glycol) (PEG) as an additive with acetone or dimethyl formamide as solvent. The morphology of the membranes has been greatly varied with the composition of the polymer and solvent. The ionic conductivity of the membranes were measured at various temperatures (−30 to 50 °C). The prepared membranes have been employed as separators in LiCoO₂/Li cells and were subjected to charge-discharge studies at 0.2 C - rate. The polymer membrane prepared with a ratio of PVdF-HFP (50):PEG (50) using dimethyl formamide as solvent delivered higher discharge capacity than the membranes prepared with acetone as solvent.     

Blends of poly(carbonate) with poly(styrene) and poly(methylmethacrylate): phase morphology,mechanical, and thermal properties

This paper is concerned with the dependence of mechanical and thermal properties of heterogeneous blends of poly(carbonate) (PC) with poly(methyl-methacrylate) (PMMA) and with poly(styrene) (PS) on the concentration of the components. PS displays a very weak phase coupling in blends with PC, whereas PMMA is characterized by a strong coupling to PC. Experimental results as well as predictions based on composite theories are reported. The general finding is that mechanical properties, such as the tensile modulus and the dynamic shear modulus, as well as thermal properties, such as thermal expansion, are (i) only weakly affected by the occurrence of a phase inversion and of a continuous phase morphology, (ii) vary continuously with the concentration of the components, and (iii) are rather insensitive to the strength of the phase coupling. The theoretical predictions on the concentration—property relationship for these properties, based on a self-consistent approach, agree very well with those observed experimentally. The elongation at break as well as the yield stress, on the other hand, are strongly influenced by the nature of the phase coupling: a discontinuous variation of these properties with the composition is observed for PS/PC blends but not for PMMA/PC blends. The general conclusion is that a set of mechanical and thermal properties of heterogeneous blends can satisfactorily be predicted on the basis of rather simple composite theories.     

Development and application of an electrochemiluminescent flow-injection cell based on CdTe quantum dots modified electrode for high sensitive determination of dopamine

A nano-liter sized flow-cell is developed for constructing a flow injection analysis (FIA) system with electrochemiluminescent (ECL) detection. A sensitive ECL electrode is applied as the working electrode in this flow-cell. It is obtained by immobilizing the composite of CdTe quantum dots (QDs), carbon nanotubes (CNTs) and chitosan (Chit) on indium tin oxide (ITO) glass. The CdTe QDs were synthesized in our lab and possessed a high quantum yield. It has been demonstrated as an efficient anodic ECL material with the triethylamine (TEA) as the co-reactant. The flow-cell gives the stable ECL background under optimized conditions for parameters such as electrolytic pulse, concentration of TEA and flow rate, etc. The sensitive ECL quenching response of dopamine (DA) is realized on this FIA system within the linear range from 10 pM to 4 nM and a detection limit as low as 3.6 pM. It is practically used to determine the neurotransmitters in cerebro-spinal fluid (CSF) with DA as the index and with an average recovery of 94%.     

以聚苯乙烯为把的聚四氢呋喃(PTHF)梳型聚合物的制备

高分子的自组装已成为当今高分子科学的热门研究课题之一[1] .开展该研究工作 ,首先要获得特定结构的聚合物 .我们设计合成如图 1所示的梳型聚合物 ,调节制备Ａ ,Ｂ ,Ｃ三链段所用的单体和它们的聚合度等参数 ,并进一步进行自组装研究 .若Ａ段是结晶聚合物 ,且熔融温度低于Ｃ段的玻璃化转变温度 ,则在定型储能材料等方面具有应用前景 .合成梳型嵌段聚合物有三个方法 ,即发散 (Ｇｒａｆｔｆｒｏｍ) ,收敛 (Ｇｒａｆｔｔｏ)和大分子方法 .采用大分子技术 ,每个梳型链长及支化密度可控 ,一直是人们青睐的方法[2 ] .一般采用与普通烯类单体共聚…     

Layered zirconium phosphate chloride dimethyl sulfoxide as a two-dimensional exchanger of anionic ligands. Part I. Substitution of chloride with inorganic monodentate ligands

Crystalline ZrPO(4)Cl(CH(3))(2)SO was prepared by direct precipitation in the presence of oxalic acid as a zirconium complexing agent. The structure of ZrPO(4)Cl(CH(3))(2)SO, refined with the Rietveld method using X-ray powder diffraction data, was confirmed to be close to that of the compound prepared using gamma-zirconium phosphate as a precursor. Chloride anions directly bonded to zirconium were found to act as weak ligands; this made possible their replacement with other monodentate anionic ligands. The preparation and a preliminary characterization of a series of inorganic derivatives obtained by topotactic replacement of Cl with OH, Br, MSO(4) (M = H, NH(4), Na), NaMoO(4), and HCrO(4) anions is reported. The possibility of replacement of chloride also with organic anions, such as alkoxides and carboxylates, and the possibility of substituting also dimethyl sulfoxide with other neutral ligands, as shown by preliminary study, makes ZrPO(4)Cl(CH(3))(2)SO a useful and very flexible precursor for materials chemistry.     

Dimeric (tris(tert-butyl)silyl)phosphanyl (tris(tert-butyl)silyl)phosphanediyl gallane: a molecule with a Ga-P-Ga heteroallyl system

The metathesis reaction of potassium (tris(tert-butyl)silyl)phosphanide with GaCl(3) in a molar ratio of 1:1 leads to the formation of [Cl(2)GaP(H)Si(t)Bu(3)](2) (1) as a mixture of cis and trans isomers with very large (1)J(P,H) and (2)J(P,P) coupling constants. The molecular structure of 1 shows a Ga(2)P(2) cycle with nearly planar coordinated phosphorus atoms under neglection of the hydrogen atoms and Ga-P distances of 239 pm. The reaction of GaCl(3) with 3 equiv of potassium (tris(tert-butyl)silyl)phosphanide as well as the reaction of 1 with 2 equiv of KP(H)Si(t)Bu(3) yields [(t)Bu(3)SiP(H)Ga(mu-PSi(t)Bu(3))](2) (2). The central moiety comprises a four-membered Ga(2)P(2) cycle with one planar P atom and extremely short Ga-P bonds of approximately 226 pm, the other being in a pyramidal environment with an angle sum of 298.4 degrees. The structure of 2 can be described as a GaPGa heteroallyl system which is bonded to a phosphanidyl substituent. This idea and its dependency on the steric demand of the trialkylsilyl groups are investigated by DFT calculations on different isomers of 2.     

A new and rapid titration of antimony(III) with potassium dichromate, with iron(II) as inductor

The optimum conditions for the titration of antimony(III) with dichromate, and diphenyl-aminesulphonic acid as indicator, have been established. No iodine catalyst is used; the analytical reaction is based on an induced reaction with iron(II) as inductor. The titration can be done as easily as an iron(II) titration and the end-point is equally sharp. Titrations are possible with 0.01N solutions.     

Reaction of (bromodifluoromethyl)phenyldimethylsilane with organometallic reagents

A new fluorine-containing organosilicon compound, (bromodifluoromethyl)-phenyldimethylsilane (II), was synthesized by the N-bromosuccinimide (NBS) bromination of difluoromethyl)phenyldimethylsilane (I), which was prepared from phenyldimethylsilyllithium and chlorodifluoromethane. Compound II reacted with dimethyl sulfoxide to give dimethyl sulfide and phenyldimethylfluorosilane in quantitative yield. The reaction of II with nucleophiles, such as sodium ethoxide, Grignard or lithium reagents, afforded products arising from cleavage of the carbonsilicon bond. In contrast, the reaction of II with Grignard reagents in the presence of appropriate catalysts (Group VIII transition metal salts or complexes) afforded the homo-coupling product of II, 1,2-bis-(phenyldimethylsilyl)-1,1,2,2-tetrafluoroethane (IV), in excellent yield. The silver(I) salt-catalyzed reaction of II with ethylmagnesium bromide gave the cross-coupling product, (1,1-difluoropropyl)phenyldimethylsilane (V) as well as III and IV. When cuprous bromide was employed as catalyst, the reaction of II with ethylmagnesium bromide afforded 1-phenyldimethylsilyl-1-propene (VI) and 3-phenyldimethylsilyl-2-pentene (VII) as main products.     

Ferric ion immobilized on three-dimensional nanoporous gold films modified with self-assembled monolayers for electrochemical detection of hydrogen peroxide

A fast, simple square wave potential method is developed for the fabrication of a three-dimensional (3D) nanoporous gold (NPG) film. The nanostructures are characterized and confirmed by scanning electronic microscopy (SEM) and cyclic voltammetry (CV). The nanostructures modified with self-assembled monolayers (SAMs) are employed as an electrode substrate to immobilize inorganic iron(III) ion. After immobilization, iron(III) ion undergoes an effective direct electron transfer reaction with a pair of well-defined redox peak at -256 ± 10 mV (pH 7.0). The iron(III) ion modified electrode displays the excellent electrocatalytic performance for reduction of hydrogen peroxide, and thus can be used as an electrochemical sensor for detecting hydrogen peroxide with a low detection limit (1.0 × 10(-9) M), a wide linear range (9.0 × 10(-7)~5.0 × 10(-4) M), as well as good stability, selectivity and reproducibility.     

镍(Ⅱ)-IMDA-HBG及镍(Ⅱ)-Tart-HBG体系的pH电位法测定——N-邻羟基苄基氨乙酸(HBG)及其络合物的研究(Ⅱ)

用pH电位法研究了在0.1MKCl水溶液中(30.0±0.1℃)的镍(Ⅱ)-亚氨基二乙酸(IMDA)与N-邻羟基等基氯乙酸(HBG)的加合反应、镍(Ⅱ)-酒石酸(Tart)与HBG的取代反应以及镍(Ⅱ)-HBG的络合反应,并测得了Ni(Ⅱ)-IMDA-HBG加合反应平衡常数K₁₁₁、混合型络合物积累生成常数β₁₁₁和Ni(Ⅱ)-Tart-HBG取代反应平衡常数K_1r、混合型络合物积累生成常数β₁₁₁以及Ni(Ⅱ)-HBG络合物的逐级生成常数K₁₀₁、K₁₀₂、积累生成常数β₁₀₂和Ni(Ⅱ)-Tart络合物的积累生成常数β₁₂₀。其结果如下:Ni(Ⅱ)-IMDA-HBG体系lgk₁₁₁7.10,lgβ₁₁₁15.36Ni(Ⅱ)-Tart-HBG体系lgk_1r5.13,lgβ₁₁₁12.68,lgβ₁₂₀。7.55Ni(Ⅱ)-HBG体系lgk₁₀₁9.07,lgk₁₀₂5.54,lgβ₁₀₂14.61讨论了pH滴定曲线、混合型络合物和Ni-HBG络合物的稳定性以及碱性范围Ni(Ⅱ)与Tart可能的络合形式。     

Transannular O-heterocyclization of twelve and thirteen membered trienes by methoxybromination procedure

The reaction of (E,E,Z)-cyclododeca-1.5,9-triene (1) with NBS and methanol gives bicyclic tetrahydrofuran derivatives (3) and (4) as well as usual 1,2-addition products while the related reaction with (Z,E,Z)-cyclotrideca-1,5,9-triene (7) leads to the bicyclic tetrahydropyran derivative (6), in both cases like O-heterocyclization products as the result of transannular participation of a methoxy group.