1-甲基环丙烯与α-环糊精包合物的合成

采用溶液包结法利用α-环糊精(α-CD)对1-甲基环丙烯(1-MCP)进行包合,将气态的1-MCP固态化形成白色粉末状的1-MCP/α-CD稳定包合物,使之便于保存和应用。利用拉曼光谱(Raman)、X射线粉末衍射光谱(XRD)、气质联用测试仪(GC-MS)、核磁谱仪(NMR)等测试技术对所得包合物的结构和组成进行表征,证明了包合物的形成,同时提出了1-MCP/α-CD包合物中1-MCP含量的快速测定方法,以该法测定的包合物中1-MCP的有效质量分数约为3.6%。对1-MCP和α-CD的包合机理进行了探讨,认为1-MCP和α-CD按摩尔比1∶1进行包合。     

二丁基羟基甲苯包合物的制备、表征及应用研究

本文采用冷冻干燥法制备获得二丁基羟基甲苯(BHT)的羟丙基-β-环糊精包合物(HP-β-CD IC)、二甲基-β-环糊精包合物(DM-β-CD IC)和磺丁基-β-环糊精包合物(SBE-β-CD IC)。相溶解度法确定了二者形成化学计量比为1:1的包合模型;粉末X射线衍射、差示扫描量热、核磁共振氢谱及扫描电镜等技术给出其可能的结合模式,并通过AutoDock分子模拟对接理论研究佐证了实验结果的可靠性;实验结果证明,三种包合物稳定性顺序为SBE-β-CD/BHT ICDM-β-CD/BHT ICHP-β-CD/BHT IC,其中SBE-β-CD/BHT包合物增溶效果最显著。1,1-二苯基-2-苦肼基(DPPH)法考察BHT三种包合物抗氧化活性的结果是:三种包合物均表现出良好的清除效果,且与BHT相当。利用β-CD衍生物的包合技术改善BHT的水溶性,是一种拓展BHT应用领域的有效策略。     

羟丙基-β-环糊精对γ-山竹黄酮的包合作用研究

采用荧光光谱法研究了羟丙基-β-环糊精(Hp-β-CD)在生理pH条件和中性条件下对γ-山竹黄酮(γ-MAG)的包合行为和增溶效果,并探讨了温度对表观包合稳定常数的影响.利用溶液-搅拌法制备了包合物,并用红外吸收光谱法、差示扫描量热分析法对其进行了表征.结果表明:在胃液pH和中性条件下,Hp-β-CD 均能与γ-MAG形成稳定的包合物,包合比分别为 1∶ 1和2∶ 1,表观包合稳定常数K分别为1.57×103 L/mol和2.7×106 L2/mol2,在中性条件下更容易形成包合物.而在肠液pH条件下,Hp-β-CD与γ-MAG没有包合现象.温度对表观包合稳定常数的影响不大.Hp-β-CD与γ-MAG形成包合物后,使 γ-MAG的溶解度增加了约31倍.     

光谱法及热动力学法研究环糊精与三氟氯氰菊酯的包合作用

制备了β-环糊精(β-CD)-三氟氯氰菊酯(CHL)包合物,采用差示扫描量热分析法和核磁共振波谱法对包合物进行表征.实验采用1HNMR研究包合物的空间结构,推测出三氟氯氰菊酯同β-CD的包合方式是从大口端进入β-CD.用化学软件对β-CD与CHL包合方式计算发现,CHL从β-CD的大口端和小口端进入,总能量分别为108.1kJ/mol与129.2kJ/mol,表明CHL从β-CD的大口端进入形成的包合物能量最低,结构最稳定.在25℃下,实验测得β-CD-三氟氯氰菊酯包合物形成常数为340.6L?mol-1,包合比是1∶1.热动力学方法研究了温度变化对包合反应的影响,计算得出包合过程的焓变-50.29kJ?mol-1、熵变120.6J?K-1?mol-1及自由能变化-14.45kJ?mol-1,进而确定了包合反应的主要驱动力是焓.     

艾叶挥发油-羟丙基-β-环糊精包合物的制备

以艾叶挥发油(艾油)和羟丙基-β-环糊精(HP-β-CD)为原料,采用搅拌法合成了艾油-HP-β-CD包合物,其结构和性能经FT-IR和TLC表征。结果表明,HP-β-CD与艾油产生了包合作用,形成了包合物,在包合过程没有改变艾油的化学成分。最佳包合条件为:艾油1 mL,m(HP-β-CD/g)∶V(艾油/mL)=8∶1,搅拌速度700r.min-1,于60℃包合3 h。在此条件下,艾油利用率为79.50%,收率为56.56%,含油率为12.57%。     

茵陈、白术挥发油-β-环糊精包合物的制备工艺研究

以挥发油的包合率和包合物收率为指标,考察制备茵陈、白术挥发油-β-环糊精(β-cyclodextrin,简称β-CD)包合物的饱和溶液法、研磨法、超声法,并采用正交设计优化研磨包合工艺,筛选出其最佳条件为:挥发油与β-CDA的投料比为1∶4,β-CD与加水量的比为1∶15倍,研磨时间40 min.该条件下的包合率为85.4%,包合物收得率为93.5%.结果表明,研磨法包合茵陈、白术挥发油的包合率和收得率较高,包合物性质稳定,而且包合前后挥发油成分一致.     

荧光光谱法研究维生素B_1与β-环糊精及其衍生物的包合作用

采用荧光光谱法研究了β-环糊精(β-CD)、甲基-β-环糊精(M-β-CD)、羟丙基-β-环糊精(HP-β-CD)、磺丁基-β-环糊精(SBE-β-CD)对维生素B_1的包合作用.在固定维生素B_1浓度和改变环糊精及其衍生物浓度的情况下,维生素B_1的荧光发射波长的变化以及荧光强度的增强表明了包合物的形成,用荧光双倒数法计算了环糊精及其衍生物与维生素B_1的包合常数.实验结果表明:在pH=7.4的体系中,β-环糊精对维生素B_1的包合能力最强,且四种环糊精与维生素B_1的包合物的包合比均为1∶1.     

紫外分光光度法及毛细管电泳法测定烷基酚与环糊精的包合常数

β-环糊精(β-CD)具有独特的外部亲水、内部疏水的空心圆台结构,能分别与对特辛基酚(OP)和正壬基酚(NP)形成包合物。该文通过紫外分光光度法测定了β-CD与OP和NP的包合比及包合常数,实验结果表明,OP和NP与β-CD均形成1∶1的包合物,包合常数分别为71.06 L/mol和1 402.72 L/mol。同时采用毛细管电泳法测定了β-CD与OP和NP在10 mmol/L磷酸二氢钠-10 mmol/L硼砂-20 mmol/L胆酸钠缓冲溶液(p H 9.0)中的包合常数,采用双倒数法计算出β-CD与OP和NP的包合常数分别为68.20 L/mol,1 357.80 L/mol。经F检验和t检验判断,两种方法所测包合常数一致。     

荧光光谱法研究氢溴酸右美沙芬与β-环糊精及其衍生物的相互作用

应用荧光光谱法研究了β-环糊精(β-CD)及其衍生物甲基-β-环糊精(Me-β-CD)、磺丁基-β-环糊精(SBE-β-CD)与氢溴酸右美沙芬(DH)的包合作用。实验固定DH浓度和改变β-环糊精及其衍生物浓度,根据DH的发射波长的变化及荧光强度增敏现象确定了包合物的形成,根据双倒数法计算包合常数。实验结果表明:在pH为7.4的条件下,有三种环糊精对药物有明显的作用,这三种环糊精与氢溴酸右美沙芬形成了包合物且包合比均为1∶1。     

荧光光谱法研究分解后白术挥发油与β-环糊精和羟丙基-β-环糊精的包合作用

采用荧光光谱法研究了多组分分解后白术挥发油(DVOA)与β-环糊精(β-CD)和羟丙基-β-环糊精(HP-β-CD)的包合作用。固定挥发油质量,考察了β-CD和HP-β-CD的浓度及包合时间对挥发油荧光强度的影响,同时采用荧光双倒数法计算了挥发油与β-CD和HP-β-CD的包合比及包合常数,并进一步研究了挥发油/HP-β-CD包合物的热力学特性。实验结果表明,挥发油的荧光强度随β-CD和HP-β-CD浓度的增大而逐渐增加,表明包合物的形成,包合比均为1∶1;25℃下挥发油与β-CD和HP-β-CD的包合常数分别为110、172L/mol,表明包合稳定性为HP-β-CDβ-CD。温度25℃、35℃和45℃下,挥发油与HP-β-CD的包合常数分别为172、130、83L/mol,△G、△H和△S均为负值,且△H小于一般反应热,表明升高温度挥发油与HP-β-CD的包合稳定性降低;包合反应可自发进行,且为放热反应,包合过程是挥发油分子与HP-β-CD分子间氢键和范德华力作用的结果。     

Dication induced stabilization of gas-phase ternary beta-cyclodextrin inclusion complexes observed by electrospray mass spectrometry

Electrospray mass spectrometry (ES-MS) is an important tool for characterization of non-covalent binding in the gas phase. In this study, iron (II) has been introduced as a dication to enhance the detection of cyclodextrin (CD) plus aromatic compound complexes in ES-MS. Evidence that a novel ternary complex comprised of one beta-CD, one iron (II) and one toluene exists as an inclusion complex has been compiled via ES-MS and ES-MS/MS experiments as well as by a computational approach. This evidence strongly suggests that iron (II) serves to modify the conformation of the beta-CD ring, and that toluene inclusion is stabilized by dication interaction with the toluene pi-system and by crimping of the beta-CD ring leading to stronger van der Waals interactions with toluene. Mg(II), another dication of similar radius, showed similar behavior, while added group one cations (H(+) and Na(+)) were ineffective at producing observable ions representative of the complex. The ternary beta-CD complex with iron (II) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) has also been examined. ES-MS and ES-MS/MS experiments suggest that it is the polar portion of 2,4,5-T (i.e., the carboxylic acid moiety) that is favored for inclusion in the beta-CD cavity, rather than the non-polar aromatic part.     

有机硅聚合物负载硫、腈钯(0)配合物催化丙烯酸衍生物芳基化的研究

钯催化下共轭烯烃的Ｈｅｃｋ芳基化是立体选择性形成碳碳键的重要方法,在有机合成中广为应用［１］．均相钯催化剂因难以从反应体系中分离回收,其实际应用受到限制．聚合物负载过渡金属催化剂因综合了均相和复相催化过程的优势,已越来越引起人们的关注,聚苯乙烯负载的膦钯配合物能有效地催化共轭烯烃的芳基化［２,３］．Ｚｈａｎｇ等报道了聚合物负载菲咯啉钯（０）配合物催化丙烯酰胺的芳基化［４］,但该催化剂的制备过程过于复杂．作者曾报道过聚γ巯丙基硅氧烷钯（０）配合物的合成,并证实其是苯乙烯、丙烯酸Ｈｅｃｋ芳基化反…     

Sodium-potassium synergism in the alkylation of toluene and naphthalene with ethene in C10H8−Na−K systems in THF

Sodium-potassium synergism in the alkylation of toluene and naphthalene with ethene in naphthalene-alkali metal systems in THF was discovered. In the case of toluene, the maximum synergistic effect is observed at an Na∶K molar ratio of 1∶1. With this Na∶K molar ratio, the yields of the products of toluene alkylation with ethene considerably increase. The efficiency of naphthalene alkylation (in the presence of toluene) is also markedly enhanced on replacement of sodium or potassium by their mixture.     

Spectrophotometric Determination of Sparfloxacin in Pharmaceutical Preparations by Ternary Complex Formation with Pd(II) and Eosin

Abstract

A simple, sensitive, and direct spectrophotometric method has been developed for the assay of sparfloxacin in bulk and pharmaceutical preparations. The proposed method is based on the formation of ternary complex between an investigated drug, palladium(II) ion and eosin in the presence of methylcellulose as surfactant and acetate buffer of pH 4.2. Spectrophotometrically, under the optimum conditions, the ternary complex showed absorption maximum at 550 nm, with apparent molar absorptivity of 2.69×10⁴ l mol^?1 cm^?1, Sandell's sensitivity of 0.01458 µg ml^?1 and linearity in the concentration range 1.6–16 µg ml^?1. The composition of the ternary complex was studied by Job's method of continuous variation and the result indicated that the molar ratio of SPFX: Pd: eosin is 1∶1∶1. The optimum reaction conditions and other analytical parameters are evaluated. The proposed method was successfully applied for the determination of SPFX in its pharmaceutical product with mean percentage recoveries of 99.71%. The observed data has been subjected to statistical analysis, which revealed high accuracy and precision.     

Ternary Molecular Complex in the Alternating Copolymerization of Methyl Methacrylate with Styrene Using Stannic Chloride

The equimolar alternating copolymerization of methyl methacrylate (MMA) with styrene (St) in the presence of stannic chloride in toluene (Tl) is investigated kinetically. The concentrations of the ternary molecular complexes, [SnCl₄-MMA … St] and [SnCl₄-MMA … T1], are calculated by use of the formation constants of the ternary molecular complexes. The rates of copolymerization under photo-irradiation and with tri-n-butyl boron-benzoyl peroxide as an initiator are proportional to the 1.5th order and 1. Oth order, respectively, of the concentration of the ternary molecular complex [SnCl₄ · MMA … St]. The alternating copolymerization precedes the homopolymerization of the methyl methacrylate charged in excess. The alternating regulation of the copolymerization is ascribed to the homopolymerization of the ternary molecular complex from the kinetic results. The magnitudes of the shifts for     

1H-NMR spectra of complexes between methacrylic monomer and ethylaluminium dichloride in toluene and methylene chloride

¹H-NMR spectra of mixtures of a methacrylic monomer such as methacrylonitrile or methyl methacrylate and ethylaluminium dichloride at various molar ratios were measured in toluene or methylene chloride at various temperatures. It was found that only one kind of binary complex is detectable in the methacrylonitrile–ethylaluminum dichloride equimolar mixture, while in nonequimolar systems there are several kinds of binary complexes, depending on the molar ratio at low temperature in these solvents. Moreover, the chemical shifts of the protons of methacrylonitrile due to complex formation with ethylaluminum dichloride show a remarkable temperature dependence in toluene, but not in methylene chloride. This fact can be interpreted by an assumption of the formation of a ternary complex of methacrylonitrile, ethylaluminum dichloride, and aromatic donor molecules, mainly due to the dipole interaction between the nitrile group complexed with ethylaluminum dichloride and aromatic donor. The orientation of toluene molecules in the ternary complex of methacrylonitrile or methyl methacrylate is discussed.     

含氮原子桥联吡咯基稀土金属双核配合物的合成及催化ε-己内酯的开环聚合反应

RE(CH2SiMe3)3(THF)2和1.5 equiv.(C4H3NHCH2)2NCH3(1)反应合成得到含氮原子桥联吡咯基稀土金属双核配合物[η1∶η1∶η1-(C4H3NCH2)2NCH3]RE{μ-η5∶η5∶η1-(C4H3NCH2)2NCH3}RE[η1∶η1∶η1-(C4H3NCH2)2NCH3](THF)[RE=Y(2),Er(3),Yb(4)],所得配合物经过核磁共振、红外和元素分析表征,配合物2和4经单晶X-Ray进一步确认结构.同时研究了稀土配合物作为单一组分催化剂催化ε-内酯的开环聚合反应.     

NMR studies of a ternary complex reagent of lithium ester enolate, chiral diether, and lithium diisopropylamide in an asymmetric Michael reaction

A ternary complex reagent of lithium ester enolate-chiral diether-lithium diisopropylamide was formed in an equimolar mixture of these reagents in toluene based on low-temperature NMR spectroscopy. The use of [⁶Li,¹⁵N]-lithium diisopropylamide as a lithiodeprotonation and complexing reagent produced two sets of doublet peaks in ⁶Li NMR of a 1:1:1 mixture of lithium enolate-chiral diether-lithium diisopropylamide, indicating the formation of a ternary complex reagent.     

6-硝基喹哪啶的合成工艺改进

以I2/KI为氧化剂,甲苯为乳化剂,对硝基苯胺(2)和巴豆醛(3)经环合反应合成了6-硝基喹哪啶(1)。最佳反应条件为:28.92 mmol,甲苯10 mL,混酸45.5 mL[V(AcOH)∶V(HCl)=1∶90],n(2)∶n(I2/KI)=1∶1,于100℃反应4 h,收率达93.1%。1的结构经1HNMR,IR和元素分析表征。     

β-环糊精-分子内电荷转移荧光探针-牛血清白蛋白三元超分子体系的荧光光谱研究

采用荧光光谱法研究了β-环糊精(β-CD)及羟丙基-β-环糊精(HP-β-CD)与分子内电荷转移荧光探针1-酮-2-(对二甲氨基苯亚甲基)-四氢萘(KDTN)的包合作用,求得了二者的包合常数和包合比.进一步研究了CDs、KDTN及牛血清白蛋白(BSA)的超分子体系,计算了结合常数和结合比.结果表明:β-CDs-KDTN-BSA能形成1∶1∶1的三元配合物,环糊精与KDTN的包合有利于与BSA作用,其结合常数大于KDTN与BAS的结合常数.