抗癌光敏剂ZnPcSP在溶液中的存在状态及其对活性的影响

研究了两亲性抗癌光敏剂磺基邻苯二甲酰亚胺甲基酞菁锌(ZnPcSP)单体与聚集体的可见吸收光谱特征以及溶剂组成对其聚集平衡的影响,得到了ZnPcSP在一系列溶剂中的聚集平衡常数.进而研究了存在状态对ZnPcSP的S₁₈₀肿瘤抑瘤率的影响.ZnPcSP在生理盐水中主要以三聚体形式存在,而在CEL溶液中,则主要以单体形式存在,后者对S180的抑瘤率是前者的8倍     

Two alkynyl functionalized Co(II)-MOFs as fluorescent sensors exhibiting selectivity and sensitivity for Fe3+ and nitroaromatic compounds

Two alkynyl functionalized 3D frameworks with different structures were successfully synthesized for selective and sensitive detection of Fe³⁺ ions and nitroaromatic compounds through fluorescence quenching.     

PVC膜修饰粉末微电极的研制及应用

聚合物具有催化、导电和选择分离等功能,将其与电极合为一体作为新的电极材料,可为改善固体电极的灵敏度、选择性和重现性提供一种新的手段［１,２］．我们用流延法［３］制得ＰＶＣ选择性渗透膜,覆盖于粉末微电极表面,制成了ＰＶＣ膜修饰粉末微电极．该电极性能稳定...     

氯化稀土催化ε-己内酯开环聚合

Ring-opening polymerization of ε-caprolactone catalyzed by rare earth chloride dissolved in N,N-dimethylformamide and adding a small amount of propylene oxide was studied.The optimum conditions for the ring-opening polymerization of CL are as follows.In the bulk polymerization: n(DMF)/n(LaCl₃)=10,n(PO)/n(LaCl₃)=20,aging temperature: 30 ℃,aging time: 1 h,c(CL)=7.91×10^-3 mol/L,c(LaCl₃)=1.58×10^-5 mol/L,the polymerization carried out at 30 ℃ for 1 h,yield=83.3%,M_ν=1.93×10⁴.In the solution polymerization: n(DMF)/n(LaCl₃)=10,n(PO)/n(LaCl₃)=20,aging temperature: 30 ℃,aging time: 1 h,toluene as the solvent,c(CL)=4.22×10^-3 mol/L,c(LaCl₃)=8.43×10^-6 mol/L,the polymerization was carried out at 30 ℃ for 2 h,yield=62.9%,M_ν=1.21×10⁴.     

菱形石墨炔薄膜He分离特性的密度泛函理论研究

氦气在科学和工业等领域中都具有不可替代的作用,其主要存在于天然气中。如何高效地从天然气中分离氦气显得至关重要。本文基于密度泛函理论(DFT)方法系统地探究了菱形石墨炔(rhombic-graphyne,R-GY)分离膜对He和其他天然气组分(Ne、Ar、CO_2、N_2和CH_4)的吸附、选择和渗透性能。结果表明,R-GY作为He分离膜可同时满足高选择性和高渗透率的要求。常温下,R-GY薄膜对He/Ne、He/CO_2、He/N_2、He/Ar和He/CH_4的选择性可分别达到2?10~7、3?10~(20)、9?10~(26)、7?10~(37)和5?10~(51),即使在600 K时仍可保持较高水平。此外,由于较低的扩散能垒,He穿透R-GY薄膜的渗透率在常温下可达到10~(-6) mol·m~(-2)·s~(-1)·Pa~(-1),高出工业标准近3个数量级;而其他气体组分在常温下的渗透率仅为10~(-58)-10~(-14) mol·m~(-2)·s~(-1)·Pa~(-1),气体无法渗透R-GY薄膜。     

四氢咪唑并[2',1':2,3]噻吩并[5,4-c]哌啶衍生物的合成及抗肿瘤活性

以4-哌啶酮为原料,经过胺基保护、缩合、环合、脱保护等步骤,设计合成了一系列新型的5,6,7,8-四氢咪唑并[2',1':2-3]噻吩并[5,4-c]哌啶类化合物。通过核磁共振波谱仪(~1H NMR、~(13)C NMR)、质谱(MS)和元素分析确证了其结构。对其体外活性研究发现,该类化合物对乳腺癌细胞MCF-7具有一定的抑制活性,其中化合物5a的抑制活性最为显著,半数抑制浓度(IC_(50))值达到了8.6μmol/L。为此类化合物的抗肿瘤活性研究提供了参考。     

金属离子与卟啉的嵌入反应动力学研究(Ⅳ)──乳酸缓冲体系中四吡啶基卟啉衍生物与铜(Ⅱ)的配位反应

研究了在35±0.1℃、离子强度0.5mol/L(KCI)下,乳酸根催化Cu²⁺离子嵌入溴化间-四(N-乙酸甲酯基-3-吡啶基)卟啉和溴化间-四(N-氰乙基-3-吡啶基)卟啉的反应动力学。根据催化剂浓度、溶液的pH值与反应速率间的关系,得到Cu²⁺离子嵌入该类卟啉的反应动力学方程。实验结果表明,该类反应遵循负离子催化卟啉变形机理,变形的卟啉及其与乳酸根离子的缔合物为可能的活性中间体。     

二苯并噻吩及其氧化物与离子液体相互作用的理论研究

采用密度泛函理论方法比较了DBT/DBTO₂和[BMIM]⁺[PF₆]^-/[BMIM]⁺[BF₄]^-的相互作用。对最稳定的[BMIM]⁺[PF₆]^-、[BMIM]⁺[PF₆]^--DBT、[BMIM]⁺[PF₆]^--DBTO₂、[BMIM]⁺[BF₄]^-、[BMIM]⁺[BF₄]^--DBT、[BMIM]⁺[BF₄]^--DBTO₂进行了NBO和AIM分析。结果表明,DBT和[BMIM]⁺[PF₆]^-/[BMIM]⁺[BF₄]^-中的咪唑环彼此相互平行,NBO和AIM分析表明它们之间发生了π-π相互作用。H1'和H9'形成的F…H氢键有利于π-π堆积作用的形成。DBTO₂倾向于趋近C2-H2和甲基基团形成O…H相互作用;DBTO₂优先吸附在[BMIM]⁺[PF₆]^-/[BMIM]⁺[BF₄]^-。在模拟油中,[BMIM]⁺[PF₆]^-和[BMIM]⁺[BF₄]^-离子液体对DBTO₂的萃取能力大于DBT,其原因是可能是DBTO₂具有较大的极性和O…H与F…H的氢键作用。     

具有cGPX活力的含硒抗体酶的酶学及动力学性质研究

通过单克隆抗体制备技术得到三株特异结合半抗原4(GSH-S-DNP二苄酯)的单克隆抗体HB4,HB5和HB7.抗体经两步化学诱变得到具有细胞谷胱甘肽过氧化物酶(cGPX)活性的含硒抗体酶mHB4,mHB5和mHB7,活力分别为170,1867,32U/μmol.其中mHB5的活力是天然兔肝cGPX的0.32倍,m4A4的1.51倍.等离子体-质谱(ICP/MS)测得每分子含硒抗体酶分子中大约存在2个硒原子.mHB5的最适pH为8.6～8.8.在pH值范围为7.0和37℃条件下,mHB5催化GSH和H₂O₂或t-ROOH反应的二级速率常数为:_k+1(H₂O₂)9.71×10⁶L/(mol·min),_k+1(t-ROOH)5.99×10⁵L/(mol·min).mHB5使非酶催化反应速率提高了9.8×10⁶和3.7×10⁵倍.     

Kinetics of formation of intermediates in silver ion assisted aquations

There is kinetic evidence of the formation of [Co(NH₃)₅NCSAg₃]⁵⁺ in the interaction of [Co(NH₃]⁵NCS]²⁺ with Ag⁺ in aqueous solution, with pseudo-first-order formation rate constant k = 0.158 s⁻¹ for the forward reaction in the following equation at 25°C and [Ag⁺] in the range of 1.23–5.0 × 10⁻² mol dm⁻³ and 0.10 ionic strength (NaClO₄):

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Additionally, the formation constant, β₂, for [Co(NH₃)₅NCSAg₂]⁴⁺ has been determined to be log β₂ = 4.717. For the [Rh(NH₃)₅I]²⁺-Ag⁺ reaction there is evidence of an outer-sphere interaction with rate constants of k₂ = 670 dm³ mol⁻¹ s⁻¹ at 25°C and 0.10 ionic strength. This outer-sphere species undergoes further reaction to give the silver ion containing intermediates of the aquation reactions.     

基于萘酰亚胺-苯并咪唑鎓的荧光传感器对H2PO-4的高选择性识别

设计合成了基于萘酰亚胺-咪唑鎓的受体分子1和2,通过荧光发射光谱研究了受体分子1和2对阴离子F^-、Cl^-、Br^-、I^-、AcO^-、HSO^-₄、H₂PO^-₄、NO^-₃、ClO^-₄的识别性能。 研究发现,在受体分子1和2的乙腈溶液(5.0×10^-6 mol/L)中加入10倍化学计量的H₂PO^-₄时,受体分子1的荧光猝灭率高达98%,受体分子2的荧光猝灭率仅为24%。 表明具有多重识别位点的受体分子1在构型上与H₂PO^-₄更匹配,可作为H₂PO^-₄的荧光关闭型(turn-off)探针。 受体分子1与H₂PO^-₄的结合比为1∶1,结合常数为(1.25±0.11)×10⁵ L/mol,检出限为6.90×10^-6 mol/L。     

A novel chemosensor-bipyridyl end capped hyperbranched conjugated polymer

A novel hyperbranched conjugated chemosensor with bipyridyl groups as periphery groups（BPY-HPV） was synthesized.BPY-HPV was highly sensitive to metal ions(Cu²⁺,Ni²⁺) for the strong coordination interaction(K_sv at the order of 10⁷ mol^-1 L) monitored by fluorescence spectroscopy.Moreover,by hydrogen bonds and charge transfer interaction,BPY-HPV shows strong interaction with 1,1,2,2-tetrachloroethane whatever in CH₂Cl₂(K_sv～10⁶ mol^-1 L) or film.     

Kinetics and Mechanism of Exothermic First-stage Decomposition Reaction of 2,6-Bis （2,2,2-trinitroethyl）glycoluril

The thermal behavior, mechanism and kinetic parameters of the exothermic first-stage decomposition of the title compound in a temperature-programmed mode were investigated by means of DSC, TG-DTG and IR. The reaction mechanism was proposed. The kinetic model function in differential form, apparent activation energy(Ea) and pre-exponential factor(A) of this reaction are (3/2)(1-a)[-ln(1-a)]1/3, 185.52 kJ/mol and 1017.78 s-1, respectively. The critical temperature of the thermal explosion of the compound is 201.30 ℃. The values of ΔS≠, ΔH≠ and ΔG≠ of this reaction are 72.46 J/(mol · K), 175.1 kJ/mol and 141.50 kJ/mol, respectively.     

Synthesis of Highly Sensitive Fluorescent Probe Based on Tetrasubstituted Imidazole and Its Application for Selective Detection of Ag+ Ion in Aqueous Media

A small molecule fluorescent probe, 4-[2-(4-chlorophenyl)-4,5-diphenyl-1H-imidazol-1-yl]aniline(L) for detecting Ag⁺ ion was gently synthesized via one-pot multi-component reaction catalyzed by H₃[PW₁₂O₄₀] under solvent-free microwave irradiation. When the concentration of Ag⁺ ion changed from 0 to 8.0×10⁻⁶ mol/L in the solution of H₂O/CH₃OH(19:1, volume ratio), the fluorescence emission spectrum was blue-shifted and accompanied by a gradual increase in fluorescence intensity with a low detection limit of 3.0×10⁻¹¹ mol/L. Moreover, UV-Vis absorption titration experiment demonstrated a 1:1 stoichiometric ratio and an association constant of (9.95±0.44)×10⁵ L/mol between probe L and Ag⁺ ion, and thus their complexation mechanism was also proposed and verified. More importantly, this fluorescent probe was remarkably specific for Ag⁺ ion under the interference of other metal ions and exhibited a wide pH application range of 4.0-8.0. Additionally, preliminary application of this probe was also carried out and satisfactory results were shown.     

基于硫代黄素T诱导G-四联体构成的生物传感器检测铅离子

硫代黄素T(ThT)荧光分子在自由状态下荧光强度很弱, 通过在Tris-HCl缓冲液中加入Pb²⁺的适配体即富含G的DNA序列, 可与ThT荧光分子形成G-四联体结构, 使荧光信号迅速增强; 向溶液中加入Pb²⁺, Pb²⁺与其适配体有很好的结合特异性, 可生成更牢固的G-四联体结构, 使ThT分子被释放出来, 导致溶液的荧光强度降低, 基于此可检测溶液中的Pb²⁺离子. 实验中优化了缓冲溶液组成、 ThT荧光分子浓度、 Pb²⁺适配体浓度及反应时间等条件. 结果表明, 在10 mmol/L Tris-HCl(pH=8.3, 含2 mmol/L MgCl₂)缓冲溶液中, ThT荧光分子和Pb²⁺适配体的浓度分别为10 μmol/L和200 nmol/L, 反应10 min时, 随着溶液中Pb ²⁺浓度的增加, 荧光强度减弱. Pb²⁺浓度在20~1000 nmol/L范围内时, 荧光强度与Pb²⁺的浓度呈现良好的线性关系(R²=0.9941), 检出限为1 nmol/L. 实际水样测试结果表明, 该方法的回收率在98.8%~101.3%之间. 该传感器灵敏、 快速、 无需化学修饰荧光分子且成本低.     

Facile synthesis of enzyme functional metal-organic framework for colorimetric detecting H2O2 and ascorbic acid

In this work,a metal-organic frameworks material MIL-88 was prepared easily using solvent-thermal method,and was first found to have catalytic activities similar to those of biological enzymes such as catalase and peroxidase.The material was characterized by XRD,SEM,TEM,EDX,FT-IR techniques and an N_2 adsorption method.It exhibited peroxidase-like activity through catalytic oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine(TMB) in the presence of H_2O_2,producing a blue-colored solution.Under optimal conditions,the absorbance at 652 nm is linearly correlated with the concentration of H_2O_2 from 2.0×10~(-6) mol/L to 2.03×10~(-5) mol/L(R~2=0.981) with a detection limit of 5.62×10~(-7) mol/L(S/N=3).More importantly,a sensitive and selective method for ascorbic acid detection was developed using this material as a catalyst.The analytical method for ascorbic acid detection was observed to have a linear range from 2.57×10~(-6) mol/L to 1.01×10~(-5) mol/L(R~2=0.989) with a detection limit of 1.03×10~(-6) mol/L(S/N=3).This work suggests MOFs have advantages of preparing biomimetic catalysts and extends applications of the functional MOFs in the field of biosensor.     

HIGHLY SENSITIVE SPECTROPHOTOMETRY OF NIOBIUM

In pH2.0-3.0,niobium(V)forms molybdonlobic acid with sodiummolybdate.A spectrophotometric method has been developed for the deter-mination of niobium based on the formation of ion-associate compound ofmolybdoniobate with Butyl Rhodamine B in aqueous solution in the presenceof polyvinyl alcohol and 0.4-0.7 mol/L H_2SO_4.The maximum absorption ofion-associate compound exhioits at 85 nm and the molar absorptivity is7.5×1.0~5 L.mol~(-1).cm~(-1)for niobium.The new method has been applied tothe determination of microamounts niobium in silicate rock,when niobiumcontent is at the level of 8×10~(-3)%,with the relative standard deviationof about 3%.     

过硫酸钾-脲氧化还原引发下的丙烯酰胺水溶液聚合

为制备高分子量聚丙烯酰胺(PAM),对其引发体系,尤其是对氧化还原引发做了许多探索^[1]。     

带有苯酚侧臂的四氮大环Zn(Ⅱ)配合物催化羧酸酯水解研究

合成并表征了在大环侧臂引入取代苯酚作为功能基团的新型四氮大环配体(L₁,L₂和L₃).对配体L₃的质子化过程及其与Zn(Ⅱ)的配位过程的研究表明,配体中的酚羟基与四氮大环环中的质子之间存在较强的氢键.测得配体及配合物中酚羟基的pK_a分别为8.3和8.5.考察了上述3个配体的Zn(Ⅱ)配合物作为水解锌酶的模拟物催化对硝基苯酚乙酸酯(NA)水解的动力学行为,测得它们催化NA水解的二级反应速率常数k_c/［(mol/L^-1·s^-1］分别为3.48×10^-2、1.52×10^-2和2.85×10^-2.     

荧光素及四碘荧光素水溶液产氢的光化学研究

荧光素水溶液(浓度1×10^-4mol/L,pH 12.5)的荧光能为三乙醇胺(TEOA)所猝灭,其规律符合Stern-Volmer方程.荧光素的单重激发态的猝灭产物,荧光素的还原态,能够在氯铂酸钾(K₂PtCl₆)的存在下还原水产氢.但荧光寿命短(7.0ns),产氢的量子产率只有0.024.四碘荧光素由于有重原子效应,其单重激发态通过系间窜越转变成三重激发态,再和TEOA反应生成还原态去还原水产氢.由于磷光寿命长(～10^-3s),产氢的量子产率达0.30.