1(R),2(R)-二(2-苯并咪唑)乙二醇四核铜(Ⅱ) 配合物的合成与晶体结构

合成了一种新配合物1（R）,2（R）－二（2－苯并咪唑）乙二醇四核铜（Ⅱ[Cu4(bbmed)4Cl2L2].Cl2(CH3OH)5(H2O)2(L=MeOH或H2O,Hbbmed=1(R),2(R)-二（2－苯并咪唑）乙二醇,bbmed表示去质子后的配体）简称Cu( Ⅱ）-bbmed)。该晶体经X－射线衍射确定为正交晶系,空间群C221（20）,晶胞参数a=1.7424(5),b=2.4942(7),c=3.8887(11)nm,V=16.900(8)nm^3,Z=4,Dc=1.427g.cm^-3,F(000)=7472,并对它进行了元素分析、IR、^1H NMR及ESR表征。     

A High－efficiency Preparation, Properties and Structure of （R, S ）－and （ S, S）－Pyrrolidine－2－carboxylic Acid 3,5－Dioxa－4－boracvclo.hepta [ 2,1－α; 3,4－α′] dinaphthalen－4－yl Esters

A highly-efficient preparative procedure for ( R, S )- and ( S, S)-pyrroHdine-2-carboxyHc acid 3,5-dioxa-4-boracyclohepta[2, 1-α ; 3,4-α′] dlnaphthalen-4-yl esters [ namely ( R, S )-BNBAP and (S, S )-BNBAP] is described and the crystal structure of (R, S )-BNBAP was obtained. The data indicate that ( R, S )-BNBAP is a spirocyclic inner borate salt with almost normal te-trahedral configuration. This structural form may be the basic reason for their high chemical, optical and thermodynamic sta-bility.     

Synthesis of Quinolone Analogues： 7-[（2S, 4R）-2-Aminomethyl-4- hydroxypyrrolidin-l-yl] Quinolones

New quinolone derivatives of 7-[(2S, 4R)-2-aminomethyl-4-hydroxypyrrolidin-l-yl] quinolone-3-carboxylic acids were synthesized by condensation of 7-halo substituted quinolone-3-carboxylic acids with (2S, 4R)-2-aminomethyl-4-hydroxypyrrolidine. These compounds were characterized by FAB-MS and IH NMR.     

A Convenient Method for Synthesis of Novel Cyclic Ethers （IR, 2R,3R, 5S, 7S, 9R, 12R）-3-（t-Butyldimethylsilyl）oxy-7-methoxymethyl- oxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.0^5,12] dodecane

Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7-methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.0^5,12] dodecane were prepared when their precursor 1 was treated with SOC12/pyridine. A plausible mechanism was hypothesized.     

Asymmetric Synthesis of （ － ）－（2R ,3R, 6S ）－Irnigaine

Asymmetric synthesis of irnigaine was achieved starting from an enantiopure β-amino ester 5 using the condensation of amino al-cohol 2 with acetylacetone and the subsequent intramolecular cycllzation as the key steps.     

Synthesis of （2R,4R）—2—N—tert—Butyloxycarbonyl Amino—4,5—epoxido—valeric Acid Methyl Ester

The stereoselective synthesis of (2R,4R)-2-N-tert-butyloxycarbonyl amino-4,5-epoxido-valeric acid methyl ester 8,which is the key intermediate for the synthesis of (2′S,2R)-3-trans-nitrocyclopropyl-alanine,was first accomplished.     

Diorgano, Dichloro－tin （IV） Complexes of 4－X－Benzohydroxamic Acid （X=CI, OCH3）： Synthesis, Characterization, Antitumor Activity in Vitro and the Crystal Structure of trans－ [Me2Sn（L2） 2]

A series of diorganotin (IV) derivatives of R2SRL2 (R = Me, Et, n-Bu, ph or CI; L = Ll or L2) and their corresponding mixed-ligand complexes RESn (L1)(L2) have been prepared and the structure of trans-MeESn (L2)2 was characterized by FT-IR, ^1H, ^13C and ^ll9Sn NMR spectroscopies,MS, elemental analysis, melting points and X-ray diffIaction. The structure-activity relationships were discussed.     

Synthesis and One－dimensional Structure of Cobalt（Ⅱ） Complex [－ （NaOC2H5） CoL2]n

The treatment of bis (2-hydroxybenzyl)-amine (HL) with NaOH and Co ( Ⅱ )(NO)2 gives isostructural one-dimensional coordination polymers [-(NaOC2H5)CoL2]n(1). The cobalt ions have an octahedral geometry and are coordinated by two erystallographicaUy independent ligands which are further linked by β-Ophenol bridged Co and Na atoms to give a one-dimentional structure.     

Synthesis and Potential Application of Novel C2-Symmetrical Bis（ferrocenyl） P2N Ligand

A novel chiral bis(ferrocenyl) P2N ligand 1 with C2-symmetry was synthesized through a four-step procedure from (R)-N,N-dimethyl-l-ferrocenylethylamine. In a model reaction of Pdcatalyzed allylic alkylation of 1,3-diphenylprop-2-enyl acetate 6 with dimethyl malonate, good enantioselectivity (86% e.e.) was obtained.     

(3R,5R)-3,5-二羟基-6-取代己酸不对称合成研究进展

概述近 2 0年来 ( 3R ,5R) 3 ,5 二羟基 6 取代己酸不对称合成进展 ,并提出其研究方向 .     

Thermokinetic Study on the Reversible Competitive Inhibition of Bovine Liver Arginase

Introduction Arginase (EC 3.5.3.1) is a widespread and very im-portant enzyme in mammals, which specifically cata-lyzes the hydrolysis of L-arginine to urea and the non-protein amino acid L-ornithine, a key step in the urea cycle.1 Urea is the principal metabolite for disposal of nitrogen as a neutral and nontoxic waste product formed during amino acid metabolism in mammals. L-ornithine serves as a biosynthetic precursor to L-proline and the polyamines such as putrescine, sper-mine (in eucar…     

A Solid Film Electrode of Intermetallic Ag2Hg3.02 for the Direct Determination of Folic Acid in Fresh and Processed Fruit Juices

AgSIE was used for the direct analysis of folic acid (FA), with a detection limit and lower level of quantitation of 6.8×10^?10 mol L^?1 and 2.3×10^?8 mol L^?1. The analysis in fresh and processed fruits was done without any sample pretreatment. In strawberry and acerola juices, FA concentration level values were below the method detection limit. FA was detectable in peach (77.7±0.4 µg L^?1 and 64.4±0.5 µg L^?1), Persian lime (45.4±0.7 µg L^?1), pineapple Hawaii (66.2±0.4 µg L^?1), pear pineapple (35.3±0.6 µg L^?1), cashew (54.4±0.5 µg L^?1), passion fruit (73.2±0.3 µg L^?1), and apple (84.4±0.5 µg L^?1).     

Kinetic Studies on the Reaction of Sodium Hexacyanoferrate（ll） Complex with Peroxydisulfate Anion

The oxidation of Na₄Fe(CN)₆ complex by S₂O anion was found to follow an outer‐sphere electron transfer mechanism. We firstly carried out the reaction at pH=1. The specific rate constants of the reaction, k_ox, are (8.1±0.07)×10^?2 and (4.3±0.1)×10^?2 mol^?1·L·s^?1 at μ=1.0 mol·L^?1 NaClO₄, T=298 K for pH=1 (0.1 mol·L^?1 HCl0₄) and 8, respectively. The activation parameters, obtained by measuring the rate constants of oxidation 283–303 K, were ΔH^≠=(69.0±5.6) kJ·mol^?1, ΔS^≠=(?0.34±0.041)×10² J·mol^?1·K^?1 at pH=l and ΔH^≠=(41.3±5.5) kJ·mol^?1, ΔS^≠=(?1.27±0.33)×10² J·mol^?1·K^?1 at pH=8, respectively. The cyclic voltammetry of Fe(CN) shows that the oxidation is a one‐electron reversible redox process with E_1/2 values of 0.55 and 0.46 V vs. normal hydrogen electrode at μ=1.0 mol·L^?1 LiClO₄, for pH=1 and pH=8 (Tris). respectively. The kinetic results were discussed on the basis of Marcus theory.     

Electroanalytical Studies on Cobalt(II) Ion‐Selective Sensor of Polymeric Membrane Electrode and Coated Graphite Electrode Based on N2O2 Salen Ligands

Poly(vinyl chloride)‐based membranes of salen ligands, 2‐((E)‐((1R,2S)‐2‐((E)‐5‐tert‐butyl‐2‐hydroxybenzylideneamino)cyclohexylimino)methyl)‐4‐tert‐butyl phenol (S₁) and 2‐((E)‐((1R,2S)‐2‐((E)‐3,5‐di‐tert‐butyl‐2‐hydroxybenzylideneamino)cyclohexylimino)methyl)‐4,6‐di‐tert‐butylphenol (S₂) were fabricated and explored as cobalt(II) selective electrodes. The performance of the polymeric membrane electrode (PME) and coated graphite electrode (CGE) were compared and it was observed that CGE showed a wide working concentration range of 1.1×10^?8 to 1.0×10^?1 mol L^?1 with a limit of detection of 7.0×10^?9 mol L^?1 exhibiting the Nernstian slope 29.6 mV/decade of activity in the pH range 3.0–9.0. It was used for the determination of cobalt(II) ions in water, soil, beer, pharmaceutical samples and medicinal plants and would be used as an indicator electrode in potentiometric titration with EDTA.     

Asymmetric Henry reactions of aldehydes with various nitroalkanes catalyzed by copper(II) complexes of novel chiral N‐monoalkyl cyclohexane‐1,2‐diamines

A number of novel chiral diamines 3 , (1R,2R)‐N‐monoalkylcyclohexane‐1,2‐diamines, were designed and synthesized from trans‐cyclohexane‐1,2‐diamine and applied to the catalytic asymmetric Henry reaction of benzaldehyde and nitromethane to provide β‐nitroalcohol in high yield (up to 99%) and good enantiomeric excess (up to 89%). By using ligand (1R,2R)‐N¹‐(4‐methylpentan‐2‐yl)cyclohexane‐1,2‐diamine ( 3g ), the reaction was optimized in terms of the metal ion, temperature, solvent and base. Further experiments indicated that the complex, 3g –Cu(OAc)₂, was an efficient catalyst in the asymmetric Henry reaction between different aldehydes and nitromethane, and the desired products have been obtained with high chemical yields (up to 99%) and high enantiomeric excess (up to 93%). The optimized catalyst promoted the diastereoselective Henry reaction of various aldehyde substrates and nitroalkane, which gave the corresponding anti‐selective adduct with up to 99% yield and 83:17 anti/syn selectivity. Upon scaling up to gram quantities, the β‐nitroalcohol was obtained in good yield (96%) with excellent selectivities (93% ee). The chiral induction mechanism was tentatively explained on the basis of a previously proposed transition‐state model. Copyright © 2014 John Wiley & Sons, Ltd.     

Electrochemical Detection of Nitrite in Meat and Water Samples Using a Mesoporous Carbon Ceramic SiO2/C Electrode Modified with In Situ Generated Manganese(II) Phthalocyanine

Mesoporous carbon ceramic SiO₂/50 wt % C (S_BET=170 m² g^?1), where C is graphite, were prepared by the sol‐gel method. The materials were characterized using N₂ sorption isotherms, scanning electron microscopy, and conductivity measurements. The matrix was used as support for the in situ immobilization of Mn(II) phthalocyanine (MnPc) on their surface. XPS was used to determine the Mn/Si atomic ratios of the MnPc‐modified materials. Pressed disk electrodes were prepared with the MnPc‐modified matrix, and tested as an electrochemical sensor for nitrite oxidation. The linear response range, sensitivity, detection limit and quantification limit were 0.79–15.74 µmol L^?1, 17.31 µA L µmol^?1, 0.02 µmol L^?1 and 0.79 µmol L^?1, respectively, obtained using cyclic voltammetry. The repeatability of the proposed sensor, evaluated in terms of relative standard deviation was 1.7 % for 10 measurements of a solution of 12.63 µmol L^?1 nitrite. The sensor employed to determine nitrite in sausage meat, river and lake water samples showed to be a promising tool for this purpose.     

Formation and Dissociation of Tetrahedral Nickel(II) and Cobalt(II) Complexes of ‘Dithioimidodiphosphato’ Ligands,Measurement of Kinetically Determined Stability Constants,and Kinetic Investigations of the Rapid Formation of Tetrahedral Bis(ligand)copper(II) Complexes and Their Rates of Reduction to Trinuclear Copper(I) Species

The stopped‐flow technique was used to measure the rates of formation and dissociation of tetrahedral [ML₂] complexes (M²⁺=Ni²⁺ or Co²⁺) of four bidentate S₂‐donor ‘dithioimidodiphosphato’ ligands L^? (HL=[R¹R²P(?S)]NH[P(?S)R³R⁴], R¹ to R⁴=alkyl) at 25.0° in MeOH/H₂O 95 : 5 (v/v) solution and in the presence of either MOPS (=3‐(morpholin‐4‐yl)propane‐1‐sulfonic acid) or 2,6‐lutidine (=2,6‐dimethylpyridine) buffers. The kinetically determined equilibrium formation constants for [ML]⁺ ions (M=Ni or Co) are 10^?5 K=0.50±0.01 or 1.64±0.07 l mol^?1 for L=L³ (R¹=R²=Me(CH₂)₂CH(Me), R³=R⁴=Me₂CH), 1.27±0.02 or 7.93±0.09 l mol^?1 for L=L⁷ (R¹ to R⁴=Me₂CHCH₂), 0.88±0.04 or 3.84±0.13 l mol^?1 for L=L⁸ (R¹ to R⁴=Me₂CH), and in case of Ni²⁺ 1.88±0.04 l mol^?1 for L=L⁶ (R¹=R³=Bu, R²=R⁴=^tBu) (see Table 3; for L³ and L⁶–L⁸, see Table 1). Whereas the tetrahedral Ni²⁺ complexes dissociate more slowly than the analogous Co²⁺ species, in all cases, the Co²⁺ complexes are more stable than those of Ni²⁺ due to their larger formation rate constants (Table 3). Reactions of Cu²⁺ with eight ligands HL (R¹ to R⁴=alkyl, alkoxy, aryl, and aryloxy) show that formation of intensely colored tetrahedral [Cu^IIL₂] species is too fast be measured with the available stopped‐flow apparatus (t_1/2<2 ms), but the subsequent rates of reduction of [Cu^IIL₂] to give trinuclear products [Cu^I₃L₃] are measurable. An X‐ray analysis establishes the structure of one of the [Cu₃L₃] complexes, where R¹=R²=Me₂CHO and R³=R⁴=2‐(tert‐butyl)phenyl (L=L⁵), and a multiwavelength stopped‐flow kinetic experiment establishes the spectrum of a tetrahedral [Cu^IIL₂] species prior to the reduction reactions. The redox reactions proceed at 25.0° with first‐order rate constants in the range 0.285 s^?1 (R¹ to R⁴=PhO; L=L¹¹) to 2.58?10^?4 s^?1 (R¹ to R⁴=Me₂CHCH₂; L=L⁷) (Table 4).     

Syntheses,characterizations, and antimicrobial activities of binuclear ruthenium(III) complexes containing 2-substituted benzimidazole derivatives

Binuclear ruthenium(III) complexes [RuX₃L]₂?·?nH₂O (X?=?Cl, L?=?L¹, L², L³; n?=?1, L⁴ and L⁵, X?=?Br; L?=?L³), [RuX₃L_1.5]₂?·?nH₂O (X?=?Br, L?=?L¹; n?=?0, L⁴; n?=?6 and L⁵; n?=?10), and [RuX₃L₂]₂ (X?=?Br, L?=?L²) have been isolated by treatment of hydrated RuX₃ (X?=?Cl/Br) in acetone with 2-(2′-aminophenylbenzimidazole) (L¹), 2-(3′-aminophenylbenzimidazole) (L²), 2-[(3′-N-salicylidinephenyl)benzimidazole] (L³), 2-(3′-pyridylbenzimidazole) (L⁴), and 2-(4′-pyridylbenzimidazole) (L⁵) in acetone. The complexes were characterized by elemental analysis, conductivity and magnetic susceptibility measurements, IR, electronic, EPR, and mass spectral studies. The complexes were dimeric; based on analytical and spectral studies, an octahedral geometry was proposed for the complexes. The synthesized complexes were screened against Gram-positive and Gram-negative bacteria and fungi.     

Highly Selective Salicylate Membrane Electrode Based on N,N＇- （Aminoethyl）ethylenediamide Bis（2-salicylideneimine） Binuclear Copper（Ⅱ） Complex as Neutral Carrier

A new ion selective electrode for salicylate based on N,N＇-（aminoethyl）ethylenediamide bis（2-salicylideneimine） binuclear copper（Ⅱ） complex [Cu（Ⅱ）2-AEBS] as an ionophore was developed. The electrode has a linear range from 1.0 × 10^-1 to 5.0 ×10^-7 mol·L^- 1 with a near-Nemstian slope of （ - 55 ±1 ） mV/decade and a detection limit of 2.0 × 10-7 mol·L^-1 in phosphorate buffer solution of pH 5.0 at 25 ℃. It shows good selectivity for Sal^- and displays anti-Hofmeister selectivity sequence： Sal^-〉SCN^-〉 ClO4^- 〉I^-〉 NO2^- 〉Br^-〉 NO3^- 〉Cl^-〉 SO3^2- 〉 SO4^2- The proposed sensor based on binuclear copper（Ⅱ）complex has a fast response time of 5-10 s and can be used for at least 2 months without any major deviation. The response mechanism is discussed in view of the alternating current （AC） impedance technique and the UV-vis spectroscopy technique. The effect of the electrode membrane compositions and the experimental conditions were studied. The electrode has been successfully used for the determination of salicylate ion in drug pharmaceutical preparations.     

Electrochemical behaviour and determination of rimsulfuron herbicide by square wave voltammetry

The voltammeric behaviour of rimsulfuron herbicide has been studied by square wave stripping voltammetry on static hanging mercury drop electrode. It exhibited a well-defined peak within the pH range of 1.0–6.0, having a maximum peak response at ?600 mV (vs.Ag/AgCl) at pH 3.0. The factors such as accumulation potential (E_acc), accumulation time (t_acc), frequency (f), pulse amplitude (ΔE) and step potential (ΔE_s) have been optimised. The calibration plot was a straight line in the range of 4.4–134.4 μg L^?1 with a detection limit of 1.3 μg L^?1. The validity of the method was assessed from the recoveries of spiked lake water, tomato juice and agrochemical formulation of Doncep^®. The results of the experiments conducted for five recoveries were 48.8 ± 1.7 and 49.7 ± 1.0 μg L^?1, which are very close to the rimsulfuron spiked to lake water and tomato juice (50 μg L^?1), with a relative error of –2.4% and ?0.6%, respectively. The electrode reaction mechanism was also postulated.