二氮杂－18－冠－6与轻稀土苦味酸盐配合物的合成及性质

合成了二氮杂－１８－冠－６（Ｌ）与轻稀土苦味酸盐的固体配合物。元素分析表明配合物的化学组成为ＲＥ（Ｐｉｃ）＿３Ｌ（ＲＥ＝Ｌａ、Ｐｒ～ｓｍ）．通过摩尔电导、红外光谱、核磁共振、热分析对配合物进行了表征。     

冠醚DPDB－18－C－6与钾显色反应的分光光度法研究

冠醚ＤＰＤＢ－１８－Ｃ－６与钾显色反应的分光光度法研究黄青瑜，营豫梅，谢明贵（四川联合大学化学系成都６１００６４）关键词钾，二苦胺基二苯并－１８－冠－６，分光光度法目前碱金属的光度测定，较为广泛的是借助阴离子染料生成三元配合物的显色方法［１－２］。近...     

二苯并18－冠－6铵与硫氰酸银配合物的晶体结构

标题化合物［（ＮＨ_４）（ＤＢ１８Ｃ６）］_２［Ａｇ（ＳＣＮ）_２］_２其晶体属三斜晶系，空间群为Ｐ１。晶胞参数：ａ＝１４．００３（２），ｂ＝１４．４６１（３），ｃ＝１４．８８７（２），ａ＝６６．５１（２），β＝６６．７０（１），γ＝７６．０９（２）°，Ｖ＝２５２７．１３　３，Ｍ_ｒ＝１２０５．０，Ｚ＝２，Ｄ_ｘ＝１．５８ｇ／ｃｍ~３，μ＝９．８８ｃｍ~（－１）。偏差因子Ｒ_ｗ＝０．０８１，独立可观测点数［Ｉ＞３σ（Ｉ）］为３３５１个，在配合物分子中，二苯并１８－冠－６与ＮＨ４~＋形成配阳离子，Ａｇ~＋与硫氰酸根形成配阴离子，二者以静电力形成配合物。银原子被两个ＳＣＮ~－的Ｓ原子桥联和硫氰酸根上的硫，氮杂配，使整个分子形成一条高分子长链。     

二苯并18－冠－6铵与硫氰酸银配合物的晶体结构

标题化合物［（ＮＨ_４）（ＤＢ１８Ｃ６）］_２［Ａｇ（ＳＣＮ）_２］_２其晶体属三斜晶系，空间群为Ｐ１。晶胞参数：ａ＝１４．００３（２），ｂ＝１４．４６１（３），ｃ＝１４．８８７（２），ａ＝６６．５１（２），β＝６６．７０（１），γ＝７６．０９（２）°，Ｖ＝２５２７．１３　３，Ｍ_ｒ＝１２０５．０，Ｚ＝２，Ｄ_ｘ＝１．５８ｇ／ｃｍ~３，μ＝９．８８ｃｍ~（－１）。偏差因子Ｒ_ｗ＝０．０８１，独立可观测点数［Ｉ＞３σ（Ｉ）］为３３５１个，在配合物分子中，二苯并１８－冠－６与ＮＨ４~＋形成配阳离子，Ａｇ~＋与硫氰酸根形成配阴离子，二者以静电力形成配合物。银原子被两个ＳＣＮ~－的Ｓ原子桥联和硫氰酸根上的硫，氮杂配，使整个分子形成一条高分子长链。     

三水合希土氯化物（镨、钆）与18－冠－6配合物的热化学研究

制备了ＲＥＣｌ３·３Ｈ２Ｏ（ＲＥ＝Ｐｒ、Ｇｄ）与１８Ｃ６的固态配合物，其化学组成为：ＲＥＣｌ３·１８Ｃ６·３Ｈ２Ｏ．对其进行了ＩＲ、溶解度、ＤＴＧ和ＴＧ分析．推测了热分解机理．测量了２９８．１５Ｋ时１８Ｃ６及两种配合物在无水乙醇中的积分溶解热，以及ＲＥＣｌ３·３Ｈ２Ｏ在１８Ｃ６－Ｃ２Ｈ５ＯＨ溶液中的溶解配位热效应．依据本文所设计的热化学循环，求得了ＲＥＣｌ３·３Ｈ２Ｏ（ｓ）与１８Ｃ６（Ｓ）生成ＲＥＣｌ３·１８Ｃ６·３Ｈ２Ｏ（Ｓ）的反应热及两种配合物的标准生成焓．     

二苯骈－21－冠－7与12－磷钨酸铯配合物的合成及表征

二苯骈－２１－冠－７与１２－磷钨酸铯配合物的合成及表征陈伟，罗良琼（四川联合大学（东区）化学系成都６１００６４）关键词合成，冠醚配合物，１２－磷钨酸铯二苯骈－２１－冠－７（ＤＢ２１Ｃ７）与含简单阴离子的铯盐配合物已有一些研究［１］，但是ＤＢ２１Ｃ７与...     

二苯并18－冠－6辅助钡离子在1，2－二氯乙烷／水微界面转移的伏安研究

应用液／液界面微电极对二苯并１８－冠－６（ＤＢ１８－Ｃ－６）辅助推动Ｂａ~（２＋）在１，２－二氯乙烷／水（ＤＣＥ／Ｗ）界面转移的电化学过程进行了详细探讨，证明该过程遵循ＴＩＣ机理，是受扩散控制的可逆过程。通过转移电流和反应物浓度之间的线性关系，测定了Ｂａ~（２＋）以及用其它方法难以测定的ＤＢ１８－Ｃ－６。     

6，6＇－二（二苯基氧化膦甲基）－1，1＇－氮氧化－2，2＇－联吡啶与硝酸铒配合物的合成与结构

合成了硝酸铒与四功能团含磷萃取剂６，６＇－二（二苯基氧化膦甲基）－１，１＇－氮氧化－２，２＇－联吡啶的配合物。用四圆衍射仪测定了配合物的晶体结构。晶体属单斜晶系，空间群Ｃ２／ｃ，晶体学参数，ａ＝１．９８３０（４）ｎｍ，ｂ＝２．３１３５（４）ｎｍ，ｃ＝１．８６００（３）ｎｍ；β＝９６．１８（２）°，ｚ＝４。配合物中有机配体以四齿形式与中心离子铒配位，金属离子的配位数为８。配位几何构形为稍变形的四方反棱柱。金属离子周围的配位水分子已全部被取代。     

三水合希土氯化物(镨、钆)与18－冠－6配合物的热化学研究

制备了ＲＥＣｌ３．３Ｈ２Ｏ（ＲＥ＝Ｐｒ，Ｇｄ）与１８Ｃ６的固态配合物，其化学组成为：ＲＥＣｌ３，１８Ｃ６．３Ｈ２Ｏ。对其进行了ＩＲ，溶解度、ＤＴＧ和ＴＧ分析，推测了热分解机理，测量了２９８．１５Ｋ时１８Ｃ６及两种配合物在无水乙醇中的积分，及ＲＥＣｌ３，３Ｈ２Ｏ在１８Ｃ６－Ｃ２Ｈ２ＯＨ溶液中的溶解配位热效应，依据本文所设计的热化学循环，求得了ＲＥＣｌ３，３Ｈ２Ｏ（ｓ）与１８Ｃ６（ｓ）生成ＲＥＣｌ３，     

钾（Ⅰ）（4＇－溴苯并－15－冠－5）配合物的研究

合成了两种新型的固体配合物，其组成为Ｋ（ＢｒＢ１５Ｃ５）Ｘ（Ｘ＝ＮＣＳ￣－或Ｐｉｃ￣－）．钾（Ⅰ）离子不仅能与４’－溴苯并－１５－冠－５形成常见的１：２夹心式配合物，而且还能生成稳定的１：１型（Ｍ：Ｌ）固体配合物．     

硫杂冠醚铜(Ⅱ)配合物构象和性质的分子力学研究

用经改进的分子力学方法MPM对一系列硫杂冠醚铜（Ⅱ）配合物进行了研究．对它们的构象和能量的分子力学计算结果表明，在这类配合物中，五员鳌环比六员鳌环稳定，随冠醚环大小和分子内张力的变化，其配合物的结构和性质有规律地变化     

The hydrogen bonding and amino-imino tautomerization of the alkoxy-aminopyridines and amino-methoxypyrimidines with acetic acid The effects of the methoxy group

The hydrogen bonding and amino-imino tautomerization of the systems of 2-amino-3-methoxypyridine (2A3MOP), 2-amino-6-methoxypyridine (2A6MOP), 2-amino-6-n-propoxypyridine (2A6NPOP), 2-amino-6-iso-propoxypyridine(2A6IPOP), 2-amino-4-methoxypyrimidine (2A4MOPM), 4-amino-2-methoxypyrimidine (4A2OPM), 4-amino-6-methoxypyrimidine (4A6MOPM), 2-amino-4-methoxy-6-methylpyrimidine (MMPM), and 2-amino-4,6-dimethoxypyrimidine (DMOPM), with acetic acid (AcOH) in n-hexane at room temperature were investigated by means of the UV absorption and fluorescence spectroscopy. From the UV absorption spectra the presence of the dual hydrogen-bonded complexes that linked by a 1:1 molar ratio with AcOH were found, since the enthalpy changes accompanying the hydrogen bond formation between 2A3MOP, 2A4MOPM, 4A2MOPM, 4A6MOPM, or MMPM, and AcOH were ca. 42.8-61.1kJmol(-1) in n-hexane. The fluorescence spectra of the 2A3MOP/AcOH, 2A4MOPM/AcOH, 4A6MOPM/AcOH, and MMPM/ AcOH systems revealed that the imino-tautomers were produced through double proton transfer in the amino hydrogen-bonded 1:1 complexes in the S1 state, but the imino-tautomer formation for the 4A2MOPM/AcOH system was not found on account of the steric hindrance due to the inversion of the methoxy group in the S1 state. The imino-tautomer for the MMPM/AcOH system fluoresces most intensely among these systems investigated. On the other hand, not only the formation of the corresponding amino dual hydrogen-bonded complex and but also that of imino-tautomer were prevented for the 2A6MOP/AcOH, 2A6NPOPM/AcOH, 2A6IPOP/AcOH, and DMOPM/AcOH systems, because of the steric hindrance of the methoxy group in both the S0 and S1 states. The theoretical approaches by an ab initio molecular orbital calculation were in accord with the experimental results.     

Lanthanide crown ether complexes of p-sulfonatocalix[5]arene

Two types of arrays are formed in water involving aza-crown ethers, p-sulfonatocalix[5]arene and europium(III) ions. One is a co-ordination polymer connecting calixarenes, sodium ions and lanthanide ions based on "ferris wheel" moieties incorporating aza-18-crown-6 and sodium ions. The second structure is a host-guest arrangement with di-protonated diaza-18-crown-6 in the cavity of the calixarenes as part of secondary coordination spheres of aquated europium(iii) ions.     

Combination of size selective binding ability of 18-crown-6 dissolved in aqueous phase and extractive properties of an amic acid; toward enhancement of rare earths separation

The separation of La(III), Eu(III) and Er(III) ions by an amic acid, N,N-dioctyldiglycolamic acid (HL), dissolved in carbon tetrachloride has been improved in the presence of 18-crown-6 (18C6) in aqueous phase as a selective masking agent. The interaction between the studied metal ions and 18C6 resulted a shift in the extraction curve of the studied metal ions versus pH toward higher pH region. The displacement of the extraction curves was more pronounced for lanthanum ions and was varied as La(III) > Eu(III) > Er(III). This order of complexing ability of 18C6 toward the studied ions was attributed to the size adaptation of the ions and that of the crown ether cavity. The stability constants of the lanthanide–crown ether complexes in aqueous phase were evaluated. The influence of temperature on the extraction of studied metal ions from aqueous phase in the absence and the presence of 18C6 was tested in the range 298–308 K. This investigation allowed evaluating the thermodynamic parameters associated with the extraction process and those of the complexation of cations by 18C6 in the aqueous phase.     

Conductance Study of 1 : 1 19-Crown-6 Complexes with Various Mono- and Bivalent Metal Ions in Water

Formation constants (ML) of 1 : 1 19-crown-6 (19C6) complexes with mono- (M+) and bivalent metal ions (M2+) were determined in water at 25 °C by conductometry. The KML value of 19C6 for M+ and M2+ decreases in the order Rb+ K+ > Tl+ > Na+ = Ag+ > Li+ Cs+ and Pb2+ > Ba2+ > Sr2+ > Cd2+ > Ca2+, respectively. The selectivity for the neighboring alkali metal ions in the periodic table is lower for 19C6 than for 18-crown-6 (18C6) except for the case of Rb+ and Cs+. The same is true for the alkaline earth metal ions. Generally, the KML values of 19C6 with M2+ are greater than those with M+. For Na+ and the ions which are smaller in size than Na+ (Li+, Ca2+, Cd2+), the KML value is larger for 19C6 than for 18C6, but the contrary holds for all the other ions of larger sizes than Na+. The limiting ionic molar conductivity (°) of the 19C6–K+ complex in water at 25 °C was determined to be 43. Although 19C6 is larger than 18C6, the 19C6–K+ complex is much more mobile in water than the 18C6–K+ complex.     

A molecular mechanics study of the selectivity of crown ethers for metal ions on the basis of their size

A molecular mechanics (MM) analysis is carried out on complexes of crown ethers CH₂(OCH₂CH₂)_nCH₂O, 12-crown-4 (n=3), 15-crown-5 (n=4), 18-crown-6 (n=5), 24-crown-8 (n=7), and 30-crown-11 (n=9) to determine the nature of the selectivity shown by these ligands for metal ions on the basis of metal ion size. The MM program used is SYBYL, and M-O bonds are represented using a covalent model, i.e. the M-O bonds are modelled with ideal M-O bond lengths and force constants. The previously used technique of calculating strain energy as a function of M-O bond length is used for all the complexes, and also the complexes of the non-macrocyclic polyethylene glycol analogues. It is concluded that the crown ethers fall into three groups with regard to selectivity for metal ions. Group one consists of the smaller macrocycles such as 12-crown-4 and 15-crown-5, where metal ions generally are too large to enter the cavity of the macrocycle, and the metal ion is coordinated lying outside the plane of the donor atoms of the ligand. Here factors that control selectivity are the same as in non-macrocyclic ligands, chiefly the size of the chelate ring. Group 2 contains only 18-crown-6 of the ligands studied here. 18-Crown-6 complexes have three important conformers, one of which, theD _3d , shows sharp size match selectivity, preferring metal ions with M-O bond lengths of about 2.9 . The other two conformers are adopted by metal ions too small for theD _3d conformer, and are more flexible, exerting little size-match selectivity. These other two conformers are of higher energy than theD _3d conformer for metal ions with M-O bond lengths greater than 2.55 . Thus, a genuine size match selectivity is found for K⁺ with 18-crown-6. With an ideal M-O bond length of 2.88 , K⁺ fits the cavity of theD _3d conformer of 18-crown-6 very closely. The third group consists of very large macrocycles such as 24-crown-8 and 30-crown-10. These enfold the metal ion in extremely folded conformations, but may, as does 30-crown-10, exert considerable selectivity for metal ions on the basis of their size by virtue of the conformation resulting in a set of torsional angles in the ring atoms of the macrocycle which confer considerable rigidity on the ligand.     

Conductance Study of Binding of Some Rb+ and Cs+ Ions by Macrocyclic Polyethers in Acetonitrile Solution

A conductance study of the interaction between Rb+ and Cs+ ions and18-crown-6 (18C6), dicyclohexyl-18-crown-6 (DC18C6), dibenzo-18-crown-6 (DB18C6),dibenzo-24-crown-8 (DB24C8), and dibenzo-30-crown-10 (DB30C10) inacetonitrile solution has been carried out at various temperatures. The formationconstants of the resulting 1:1 complexes were determined from the molarconductance-mole ratio data and found to vary in the orderDC18C6 > 18C6 > DB30C10 > DB18C6 DB24C8for Rb+ ion andDC18C6 > 18C6 > DB30C10 DB24C8 > DB18C6for Cs+ ion. The enthalpy and entropy of complexation were determined fromthe temperature dependence of the formation constants. The complexes with the18-crowns are both enthalpy and entropy stabilized while, in the case of largecrown ethers, the corresponding complexes are enthalpy stabilized but entropydestabilized.     

色层法检测王冠化合物对稀土元素的络合能力

本文应用反相纸色层法和静态吸附平衡法检测了王冠化合物与稀土离子之间的络合能力和水相阴离子类型对络合能力的影响。所用的王冠化合物有:B-15-C-5,DB-18-C-6,四氢呋喃丙酮四聚体,DB-18-C-6-甲醛缩聚物和B-15-C-5-甲醛缩聚物。得到如下主要结果:1.不同王冠化合物的络合能力顺序是;B-15-C-5>DB-18-C-6》四氢呋喃丙酮吗聚体,另B-15-C-5-甲醛缩聚物>DB-18-C-6-甲醛缩聚物。2.稀土离子络合能力的顺序是:Sm³⁺Er³⁺=La³⁺(反相纸色层法),Er³⁺>Eu³⁺>La³⁺(吸附平衡法)。3.与不同阴离子缔合的离子对的稳定性顺序是:苦味酸根>三氯代乙酸根>磺基水杨酸根》Cl^-、NO₃^-、ClO₄^-及SO₄⁼。     

Synthesis and rare earth metal ion-sensing properties of aza-crown derivative incorporating with diaryl-1,3,4-oxadiazole

A new fluorescent chemosensor (A18C6-Ox) in which a monoaza-18-crown-6 is linked to a diaryl-1,3,4-oxadiazole fluorophore by a methylene spacer has been synthesized to evaluate binding interaction with the rare earth ions by means of absorption and emission spectrophotometry. Absorption spectra of A18C6-Ox showed a broad band at 289nm and there was no significant change in the presence of Sc3+, La3+, Pr3+, Sm3+, Gd3+, Tb3+, Yb3+ and Lu3+ except for Ce3+ and Eu3+. From the emission spectral change of A18C6-Ox, interaction of the rare earth ions with A18C6-Ox is very strong. The formation of A18C6-Ox complexing with Sc3+, La3+, Pr3+, Sm3+, Gd3+, Tb3+, Yb3+ and Lu3+ leads to an increase in fluorescence intensity of A18C6-Ox, while Ce3+ and Eu3+ ions interact strongly causing fluorescence quenching of A18C6-Ox. In addition, the optimal complexation stoichiometry of the rare earth ions with A18C6-Ox was investigated by the fluorescent titration.     

Competitive Potentiometric Study of a Series of 18-crown-6 with Some Alkali and Alkaline Earth Metal Ions in Methanol Using an Ag+/Ag Electrode

The complexation of some alkali and alkaline earth cations with18-crown-6(18C6), dibenzo-18-crown-6 (DB18C6), dicyclohexyl-18-crown-6 (DCY18C6), and dibenzopyridino-18-crown-6 (DBPY18C6) in a methanol solution has been studied by a competitive potentiometric titration using Ag⁺/Ag electrode as a probe. The stoichiometry and stability constants of the resulting complexes have been evaluated by the MINIQUAD program. The stoichiometry for all resulting complexes was 1:1. The order of stability of Ag⁺ complexes with desired crown ethers varied as DBPY18C6 > DCY18C6 > 18C6 > DB18C6.The stability of the resulting complexes for each of these crown ethers varies in the order ofK⁺ > Na⁺ and Ba²⁺ > Sr²⁺ > Ca²⁺ > Mg²⁺.For each of the used metal ions the major sequence of the stability constants of the resulting complexes varies as DCY18C6 > 18C6 > DB18C6 > DBPY18C6 with minor exceptions.