含酰胺和硫脲单元的杯[4]芳烃衍生物的合成

杯[4]芳烃．1,3-二乙酸乙酯衍生物与水合肼反应生成杯[4]芳烃酰肼衍生物(2),2与异硫氰酸苯酯反应得到新型含酰胺和硫脲单元的杯[4]芳烃衍生物,总产率85％。     

硫杂杯[4]芳烃酰胺基硫脲衍生物的合成

硫杂杯[4]芳烃四乙酸乙酯衍生物与水合肼反应生成硫杂杯[4]芳烃四酰肼衍生物(3),3与异硫氰酸苯酯反应得到新型硫杂杯[4]芳烃酰胺基硫脲衍生物,总产率61%。     

新型杯[4]芳烃衍生物的合成及其氨基酸萃取性能

杯[4]-1,3-二乙酸乙酯衍生物(1)与水合肼反应生成杯[4]芳烃酰肼衍生物(2),化合物(2)与异硫氰酸苯酯反应得到含酰胺和硫脲单元的新型杯[4]芳烃衍生物(3).总产率达70%.系列氨基酸萃取实验表明化合物(3)对异亮氨酸有较好的选择性萃取能力.     

N-硫脲基套索杯[4]冠醚与四硫脲基杯[4]芳烃的合成

控制反应物的物质的量比, 杯式对叔丁基杯[4]-1,3-二乙酸乙酯衍生物1与5或50倍二乙烯三胺反应, 分别得到杯[4]氮杂冠醚2和开链的氮杂杯[4]芳烃衍生物3. 化合物2和3进一步与异硫氰酸苯酯反应得到首例侧链含硫脲基的套索杯[4]氮杂冠醚4和含4个硫脲基的杯[4]芳烃衍生物5, 产率为92%和87%. 新化合物的结构与构象经元素分析、红外、质谱、核磁共振谱等表征证实.     

四硫脲基杯[4]芳烃衍生物的合成

对叔丁基杯[4]-1,3-二乙酸乙酯与过量的二乙基三胺反应,生成含有游离氨基的杯芳烃酰胺衍物(2),2再与异硫氰酸苯酯反应合成了含4个硫脲基的杯[4]芳烃衍生物,其结构经1H NMR,IR,MS和元素分析表征。     

含硫脲基的多重氮杂杯[4]芳烃衍生物的合成与有机染料配合性能

以杯[4]芳烃为平台,构筑结构与识别性能独特的杯[4]芳烃衍生物是有机超分子化学的重要研究领域.本文中,杯[4]二芳胺基衍生物3与异硫氰酸苯酯反应得到开链的二硫脲基杯[4]衍生物4,产率为95%.化合物3与等物质的量对二异硫氰酸苯酯反应得到二硫脲基桥连杯[4]衍生物5,产率为80%.与过量的对二异硫氰酸苯酯反应则以产率为82%得到化合物6.化合物6进一步与水杨酰肼反应得到含硫脲基的多重氮杂杯[4]衍生物7,产率为75%.紫外光谱配合实验表明新主体分子4~7对测试的4种有机染料分子(橙黄Ⅰ、茜绿素、维多利亚蓝和亚甲基蓝)均显示出较强的配合能力,配合常数的数量级达10~5,配合比为1∶1.开链结构与多重胺基和芳基结构更有利于配位包合能力的提高.     

杯[4]芳烃单取代1,3-二酮衍生物的合成及生物活性研究

以杯[4]芳烃为原料经醚化和克莱森缩合两步反应首次合成杯[4]芳烃单取代1,3-二酮衍生物,其结构经1H NMR、13C NMR及MS表征。初步的HIV-1整合酶链转移反应活性测试结果表明,该杯[4]芳烃单取代1,3-二酮衍生物在测试浓度为25μM时其抑制率为12.67%。     

新型手性杯[4]氮杂冠醚衍生物的简便合成及其对甲醇分子的包结行为

本文报道新型手性杯[4]氮杂冠醚衍生物的简便合成.即在路易斯酸（ZnCl2）催化下,二氰基取代杯[4]芳烃与各种光学活性的1,2-氨基醇反应,高产率得到了手性杯[4]氮杂冠醚衍生物.该方法具有反应条件温和、操作简便、产率高等特点.产物的晶体X-衍射及ESI-MS数据表明,通过主客体之间的O–H…π作用,杯芳烃上沿的空腔对甲醇分子具有较强的包结作用.     

杯芳烃衍生物液－液萃取和液膜传输银的对比研究及机理探讨

以4类含硫、硒、氮等杂原子基团二取代的杯[4]芳烃五衍生物（1－14）为中 性载体，在H2O-CHCl3-苦味酸体系萃取银和H2O-CHCl3-H2O液膜体系中传输银进行 了对比研究。萃取和传输结果具有一致性，除了苯并噻唑取代的杯[4]芳烃衍生物 （3－6）外，其它10个含硫、硒、氮的杯[4]芳烃衍生物1－14均对软重金属银和汞 有很高的选择性，而吡啶取代的杯[4]芳烃衍生物7－10对铅有一定的萃取选择性， 其中羟基硫醚取代的杯[4]芳烃衍生物11－14对银的萃取率和传输速率最大。并且 就杯[4]芳烃衍生物对银的传输机理进行了探讨，发现传输速率随源相中金属离子 浓度和有机相中载体浓度的增加而增大，因此推论这是由金属离子浓度梯度推动下 的传输。     

苄连氮基桥联的双杯[4]芳烃的合成

对叔丁基杯[4]芳烃-1, 3-二醛基衍生物1分别与水杨醛腙、水合肼进行“1＋2”和“2＋2”缩合反应, 方便地合成了苄连氮基取代或桥联的新型杯[4]芳烃衍生物2和双杯[4]芳烃衍生物3, 产率分别为84%和81%. 新化合物的结构与构象经元素分析、质谱、核磁共振谱和1H-1H COSY谱图等表征证实, 双杯[4]芳烃衍生物3为空间结构完全对称的具有管状三维空腔的杯式构象.     

Two-arm ferrocene amide compounds: synclinal conformations for selective sensing of dihydrogen phosphate ion

[structure: see text] Ferrocene compounds bearing multiple amido groups selectively bind with the H(2)PO(4)(-) ion over other anions. The one-arm receptors form 1:1 complexes with the H(2)PO(4)(-) ion, whereas the two-arm receptors can accommodate two H(2)PO(4)(-) ions. The complexation modes and binding strengths are deduced from the NMR, calorimetry, fluorescence, and cyclic voltammetry studies. The two-arm ferrocene hexamide receptors likely exist in synclinal conformations to incorporate tetrahydrofuran molecules and H(2)PO(4)(-) ions.     

Inclusion complexes of phosphorylated daidzein derivatives with β-cyclodextrin: Preparation and inclusion behavior study

In the present work the feasibility of β-cyclodextrin in complexation was explored, as a tool for improving the solubility and biological ability of daidzein derivatives. A series of phosphorylated daidzein derivatives featuring different chain lengths were synthesized through a modified Atherton-Todd reaction and their inclusion complexes with βCD were prepared by coprecipitation method. The inclusion complexation behavior was studied by fluorescence, UV, FT-IR, MS and (1)H NMR. The results showed that only phosphorylated daidzein derivative carrying small substituent group ((C(2)H(5)O)(2)PO) entered the cavity of βCD and formed 1:1 inclusion complex. The formation constant was 175(mol/L)(-1).     

Surface properties of various powdered hydroxyapatites

Electrophoretic mobilities of various synthetic and semisynthetic hydroxyapatites (Ca10(PO4)6(OH)2, HAP) suspended in aqueous solutions have been measured as a function of pH and calcium concentration. The studied powders differ in particle size, crystallinity degree and surface contamination (carbonate). When equilibrated in mineral acids or bases, a large plateau of negative mobility is observed in the pH range 5-8, with increasing negative values at higher pH. Only in the case of the sample composed of nanoparticles, positive mobility obtains at pH < 8.9. When Ca2+ is added, positive mobility values are observed for all samples, and a bell-shaped profile results as a function of pH. Two possible models are explored to describe the results: the Nernstian approach, which assumes solubility equilibrium and surface potentials determined by the three potential-determining ions (Ca2+, PO3-4, and OH-), and the surface complexation approach, based on the idea of negligible phase transfer of structural phosphate. The Nernstian model is inadequate, whereas a very simple surface complexation model based on the equations Ca5(PO4)+3 = Ca4(PO4)-3 + Ca2+,Ca4(PO4)-3 + H+ = Ca4(PO4)2(PO4H),Ca5(PO4)+3 + OH- = Ca5(PO4)3(OH),coupled with a very simple electrical double layer, model suffices to reproduce the bell-shaped profile of the mobility as a function of pH in the presence of added calcium salts. The results also show that the sample composed of nanoparticles exchanges ions more easily with the solution, without reaching the solubility equilibrium in the explored timespans. In the presence of soluble phosphate salts, it is postulated that the same surface ensembles define the surface charge, with participation of phosphate as described by the equation Ca5(PO4)+3 + PO3-4 = Ca4(PO4)-3.HAP is just one member of a family of calcium phosphates with different (Ca)/(P) ratios. Electrophoretic mobilities of another member, tricalcium diphosphate, Ca3(PO4)2, were also measured and shown to be described by the same basic model. Comparison with previous literature data shows that the negative plateau in the mobility is a general feature of many HAP samples at low Ca2+, again in agreement with the surface complexation model. FTIR data demonstrates that surface phosphate indeed undergoes protonation, as postulated in the model.     

New insights on anion recognition by isomers of a calix pyrrole derivative

Two isomeric structures of meso-tetramethyltetrakis(3-hydroxyphenyl)calix[4]pyrrole, 4-alphaalpha betabeta and 4-alphabeta alphabeta, have been isolated and characterized by 1H NMR in different solvents (CD3CN, CD3OD, and DMSO-d6) at 298 K. Standard Gibbs energies of solution derived from solubility data in various solvents were used to calculate the transfer Gibbs energy, delta(t)G(o), of these ligands using acetonitrile as the reference solvent. These results are consistent with the 1H NMR studies in different media that show chemical shift changes observed in the resonances of the NH and the OH protons of these ligands. Solvate formation was observed when these isomers were exposed to saturated atmosphere of N,N-dimethylformamide, dimethyl sulfoxide and propylene carbonate. Anion interaction involving 4-alphaalpha betabeta and 4-alphabeta alphabeta was investigated by 1H NMR in CD3CN while the complex composition was assessed through conductance measurements. Significant differences are observed in the affinity of these ligands for anions as well as in the composition of the fluoride complexes. Thus 4-alphaalpha betabeta shows selectivity for H2PO4(-) in acetonitrile while its isomer 4-alphabeta alphabeta is selective for the fluoride anion. Again the complex composition is altered for the fluoride anion when complexed with 4-alphaalpha betabeta in acetonitrile (1:1 complex) relative to 4-alphabeta alphabeta in the same solvent. The latter isomer shows an enhanced hosting ability for this anion. Thus two anions are taken up per unit of ligand. The thermodynamics of complexation of H2PO4(-) and these ligands in acetonitrile is discussed, and the results are compared with those involving calix[4]pyrrole and this anion in this solvent. It is shown that the isomers interact with two H2PO4(-) anions while one calix[4]pyrrole unit interacts with this anion. This paper demonstrates for the first time that the enthalpy parameter may be a suitable reporter of the number of hydrogen bonds formed when calix[4]pyrrole and its derivatives interact with the dihydrogen phosphate anion in acetonitrile. In moving from acetonitrile to N,N-dimethylformamide, 4-alphaalpha betabeta is unable to enter complexation with most anions, except fluoride, with which the formation of a 1:2 (ligand:anion) complex is demonstrated. The rather versatile behavior of these receptors for anions is explained on the basis of 1H NMR evidence and solvation effects. These investigations highlight the importance of the medium effect on the stability of the complex and reflect the inherent nature of the solvent and its highly significant involvement in the complexation process.     

Host-guest complexation of a fluorescent and electrochemical chemsensor for fluoride anion

Host-guest complexation of a ferrocenenylphalene dyad 1, 1,1'-diaceylferrocenyl-3-hydroxyl-2-naphthoylhydrazone, as a fluorescent and electrochemical chemosensor for fluoride anion, was investigated. Crystal structure analysis revealed that the two naphthyl arms of compound 1 positioned in the same side about the ferrocene moiety and interacted through pi-pi stacking interactions. The intermolecular pi-pi stacking interactions and the C-H...pi interactions between the ferrocene moieties and the naphthalene rings linked the molecules together featuring a two-dimensional layered structure. Fluorescence titrations of compound 1 indicated that in the presence of F- and H2PO4-, the emission intensities enhanced significantly. Electrochemical titrations revealed that compound 1 sensed the F- anion in high selectivity with a cathodic shift of 120 mV, and had no sense in recognizing H2PO4- anion. 1H NMR titrations demonstrated that while compound 1 hydrogen-bonded to H2PO4- forming simple 1 : 1 host-guest complex, further addition of F- induced the deprotonation of compound 1.     

(Thio)ureido anion receptors based on a 1,3-alternate oxacalix[2]arene[2]pyrimidine scaffold

In pursuit of highly preorganized macrocyclic host molecules for the complexation of anions, a series of oxacalix[2]arene[2]pyrimidine-based bis(thio)ureido receptors were synthesized and fully characterized. The pincer-like 1,3-alternate conformation of the oxacalix[4]arene scaffold, essential for an efficient host-guest interaction, was visualized by single-crystal X-ray analysis and supported by variable-temperature NMR studies. The anion binding properties of the receptors were evaluated via (1)H NMR titration experiments, showing intermolecular interactions with H(2)PO(4)(-), AcO(-), BzO(-), and Cl(-) ions. The host molecule bearing 4-nitrophenyl substituents on the bisurea binding pocket showed association constants in the range of 200-400 M(-1) in the strongly competitive solvent mixture of DMSO/0.5% H(2)O.     

对二甲氨基苯甲酸的阴离子识别应用研究

采用紫外分光光度法和荧光分光光度法研究了主体分子对二甲氨基苯甲酸与HPO42-、SO42-、H2PO4-、ClO4-、HSO4-、NO3-、BF4-、PF6-、F-、Cl-和Br-等11种阴离子客体的识别作用.发现在乙腈溶液中,该主体分子对二价阴离子HPO42-和SO42-表现了强亲和力和高选择性;并对一价阴离子F-和H2PO4- 具有一定的响应能力;而与一价阴离子ClO4-、HSO4-、NO3-、BF4-、PF6-、Cl-和Br-几乎没有作用.结果表明主客体分子本身的酸碱性和阴离子的负电荷数目是影响主体分子对阴离子识别性能的主要因素.     

磷酸根离子在阴离子交换树脂上的保留行为及其机理探讨

首次发现磷酸根离子在阴离子交换柱上以两个色谱峰流出。在研究磷酸根离子的保留行为的基础上,提出了Ｈ２ＰＯ－４在固定相中进一步离解的保留机理,即Ｈ２ＰＯ－４在与阴离子交换树脂交换基进行离子交换的过程中,由于树脂交换基和淋洗离子的电荷相互作用促使一部分Ｈ２ＰＯ－４进行第２级离解。由于Ｈ２ＰＯ－４和ＨＰＯ２－４在阴离子交换树脂上的保留值不同,导致磷酸根离子出现“双峰”。     

香豆素衍生物对阴离子的识别特性

用紫外光谱滴定法研究了3种香豆素衍生物与阴离子间存在的特殊识别行为,比较了受体分子结构对阴离子配合物稳定性的影响,以及阴离子浓度对配合物光谱的影响.实验结果表明:受体分子对F^- 、Cl^-、Br^-、Ac^-、H₂PO₄^-、HSO₄^-等不同种阴离子客体的识别能力存在一定差异,受体分子与阴离子通过氢键结合,由于氢键良好的方向性和选择性,对F^-、Ac^-、H₂PO₄^-等有较好的选择性和识别能力,而与其他的阴离子几乎没有作用.     

Broensted酸性离子液体催化醛（酮）与二元醇的缩合反应

研究了以Broensted酸性离子液体1-正丁基-3-甲基咪唑磷酸二氢盐（BMImH2PO4）为催化剂，在不使用其它有机溶剂且无需脱水的条件下，于室温下进行醛（酮）与二元醇的缩合反应，得到了由中至高的转化率和高选择性，产物1，3-二口恶戊烷可以和反应物自动分层，后处理操作简单过量的醇与离子液体可以多次重复使用，且醛（酮）的转化率无明显降低。