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1.
臂式冠醚由于其侧臂基团可以不同程度改变冠醚的供电子能力、冠醚环的构象、亲水性等,从而使其与金属离子的络合性能发生变化。以二苯并14-冠-4冠醚(DB14C4)为基础,选取羟基(-OH)、氨基(-NH_2)、羟甲基(-CH_2OH)、氨甲基(-CH_2NH_2)四种侧臂基团,基于密度泛函理论(DFT),在水溶剂模型下,研究了不同侧臂基团对DB14C4与Li(I)络合过程的影响.从结构优化、前线轨道(HOMO、LUMO)及静电势(ESP)、独立梯度函数(IGM)方面进行了分析.结果表明,羟甲基的引入可改善冠醚的配位能力,为高选择性冠醚的设计提供理论支持.  相似文献   

2.
二苯并-18-冠-6-铵与硫氰酸钴配合物的晶体和分子结构   总被引:1,自引:0,他引:1  
樊悦明  周忠远 《化学学报》1986,44(7):699-703
冠醚化合物因具有环状空腔结构的特点而有独特的配位性能.随着冠醚环上杂原子的数目、种类不同(如氧、氮、硫、磷)而有不同的配合能力及其配位本质.除此之外,冠醚环上电子密度分布对配位能力具有重要作用;金属离子的电子结构对配位性质也有很大影响.对于不是很大的冠醚环来说,通常只配位碱金属、碱土金属、镧系、锕系元素,而较难配位过渡金属离子.近年来,有人通过在冠醚环上引进吸电子基团,减低环上氧原子的电子给予体性质,以求改变配位性能.我们感兴趣的是在以普通冠醚为配体时,配合物同时包含有碱金属与过渡金属离子的配位情况与结构.作者曾对18-冠-6在有钾离子与钴离子体系中的配位情况与晶体结构作了报道,本文研究了硫氰酸铵及氯化钴与二苯并-18-冠-6反应生成的配合物结构及其特点.  相似文献   

3.
本文通过双(2-羟基乙基)碲醚与二醇的二对甲苯磺酸酯缩合, 首次合成了一类新型的冠醚-碲杂冠醚及其中一个碲杂冠醚与二氯化铂的配合物,并对碲杂冠醚的合成方法.结构特征以及配位性能等进行了讨论.  相似文献   

4.
通过1H NMR, ESI-MS, 紫外-可见光谱等分析手段研究了两个新的质子化联吡啶盐客体与冠醚二苯并-24-冠-8在溶液中和气态下的包合行为. 研究结果表明, 质子化的联吡啶盐与冠醚主要形成1∶1的超分子包合物, 且存在夹心式的几何结构, 双质子化的联吡啶盐比单质子化的联吡啶盐具有更强的结合冠醚的能力, 其缔合常数分别为200, 116 L•mol-1.  相似文献   

5.
本文对二苯并-18-冠醚-6进行硝化,然后将产物与钾盐反应,生成了二硝基-二苯并-18-冠醚-6-硫氰化钾一水络合物。用元素分析、红外光谱及X光衍射法测定了结构。  相似文献   

6.
二氨基二苯并-14-冠-4的合成与表征   总被引:7,自引:0,他引:7  
二硝基二苯并冠醚;二氨基二苯并冠醚;二氨基二苯并-14-冠-4的合成与表征  相似文献   

7.
亲脂性强的冠醚化合物对金属离子选择性高、络合性能好,是高效率的相转移催化剂。对于二苯并型大环冠醚,在其芳环上引入烷基是增强冠醚脂溶性的一种有效途径;在其冠醚的脂环上引入烷氧基是提高冠醚脂溶性的又一方便的方法。为此,我们将开链冠醚(Ⅰ)与环氧氯丙烷反应得到6-羟基二苯并-16-冠-5(Ⅰ)。(Ⅱ)转化为钠盐。钠盐分别和硫酸二甲酯及7种卤代烃缩合成一组带有6-烷氧基的二苯并型冠醚化合物Ⅲ_(a—h)。反应为:  相似文献   

8.
通过氯甲基化反应,将冠醚二苯并-18-冠-6(DBC)转变为氯甲基化的冠醚(CMDBC),使交联聚乙烯醇(CPVA)微球表面的羟基与CMDBC之间发生亲核取代反应,从而实现冠醚的固栽化,制得了固载有冠醚的功能微球DBC-CPVA.在建立了冠醚DBC固载量测定方法(溴百里香酚蓝-固相萃取法)的基础上,重点研究了主要因素对DBC固栽化过程的影响规律.结果表明:反应温度与溶剂性质对DBC在CPVA微球上的固载化反应有较大的影响,在70℃极性较强的N,N-二甲基甲酰胺(DMF)溶剂中,可制得冠醚DBC固载量为1.72 mmol/g的DBC-CPVA功能微球.  相似文献   

9.
含二苯并-18-冠-6冠醚环的偶氮型液晶冠醚的合成   总被引:3,自引:0,他引:3  
含二苯并-18-冠-6冠醚环的偶氮型液晶冠醚的合成;偶氮型;冠醚;热致性液晶;合成  相似文献   

10.
以二甘醇和邻苯二酚为原料制得二苯并-18-冠-6;以多聚磷酸为催化剂和溶剂,将二苯并-18-冠-6与叔丁醇反应实现叔丁基化;利用正庚烷重结晶对叔丁基化反应产物进行纯化,得到4,4′-二叔丁基二苯并-18-冠-6和4,5′-二叔丁基二苯并-18-冠-6两种对称的二叔丁基二取代苯并冠醚产品.利用红外光谱和核磁共振谱表征了二叔丁基二取代苯并冠醚产物的结构。  相似文献   

11.
由三价轻稀土、钇(Ⅲ)和铈(Ⅳ)的硝酸盐分别与2,3,11,12-四苯基-1,4,7,10,13,16-六氧-2,11-十八环二烯反应,合成了相应的六种固体络合物,並进行了元素分析,IR、NMR、TG、DTA、电导及溶解度等性质的研究。  相似文献   

12.
The reaction of Ln(NO3)3·6H2O (Ln=La, Ce, Pr or Nd) with a sixfold excess of Ph3PO in acetone formed [Ln(Ph3PO)4(NO3)3]·Me2CO. The crystal structure of the La complex shows a nine-coordinate metal centre with four phosphine oxides, two bidentate and one monodentate nitrate groups, and PXRD studies show the same structure is present in the other three complexes. In CH2Cl2 or Me2CO solutions, 31P NMR studies show that the complexes are essentially completely decomposed into [Ln(Ph3PO)3(NO3)3] and Ph3PO. Similar reactions in ethanol gave [Ln(Ph3PO)3(NO3)3] only. In contrast for Ln=Sm, Eu or Gd, only the [Ln(Ph3PO)3(NO3)3] are formed from either acetone or ethanol solutions. For the later lanthanides Ln=Tb–Lu, acetone solutions of Ln(NO3)3·6H2O and Ph3PO gave [Ln(Ph3PO)3(NO3)3] only, even with a large excess of Ph3PO, but from cold ethanol [Ln(Ph3PO)4(NO3)2]NO3 (Ln=Tb, Ho–Lu) were obtained. The structure of [Lu(Ph3PO)4(NO3)2]NO3 shows an eight-coordinate metal centre with four phosphine oxides and two bidentate nitrate groups. In solution in CH2Cl2 or Me2CO the tetrakis-complexes show varying amounts of decomposition into mixtures of [Ln(Ph3PO)3(NO3)3], [Ln(Ph3PO)4(NO3)2]NO3 and Ph3PO as judged by 31P{1H} NMR spectroscopy. The [Ln(Ph3PO)3(NO3)3] also partially decompose in solution for Ln=Dy–Lu, forming some tetrakis(phosphine oxide) species.  相似文献   

13.
A series of new complexes of formula Ln(acac)_s(Ph_3PO)_3 (where Ln~(3+)=Nd~(3+), Sm~(3+), Eu~(3+), Tb~(3+), Ho~(3+)) have been prepared and characterized. The coordination of two ligands with lanthanide ions are studied by IR spectra, ~1H, ~(13)C, ~(31)P-NMR and metal-ligand charge tranafer tranaition is also discussed via electronic adaorption and luminescence spectroscopy.  相似文献   

14.
LnCl3 (Ln=Nd, Gd) reacts with C5H9C5H4Na (or K2C8H8) in THF (C5H9C5H4 = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C5H9C5H4)LnCl2(THF)n (orC8H8)LnCl2(THF)n], which further reacts with K2C8H8 (or C5H9C5H4Na) in THF to form the litle complexes. If Ln=Nd the complex (C8H8)Nd(C5H9C5H4)(THF)2 (a) was obtained: when Ln=Gd the 1 : 1 complex [(C8H8)Gd(C%H9)(THF)][(C8H8)Gd(C5H9H4)(THF)2] (b) was obtained in crystalline form.

The crystal structure analysis shows that in (C8H8)Ln(C5H9C5H4)(THF)2 (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η5), cyclooctatetraenyl (η8) and two oxygen atoms from THF are coordinated to Nd3+ (or Gd3+) with coordination number 10.

The centroid of the cyclopentadienyl ring (Cp′) in C5H9C5H4 group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd3+ (or Gd3+). In (C8H8)Gd(C5H9C5H4)(THF), the cyclopentyl-cyclopentadienyl (η5), cyclooctatetraenyl (η8) and one oxygen atom are coordinated to Gd3+ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd3+, which is almost in the plane (dev. -0.0144 Å).  相似文献   


15.
通过水热反应合成5种结构新颖的配聚物:{[Ln_2(1,3-bdc)_3(H_2O)_4](DMF(H_2O}_n[Ln=Pr(1),Nd(2),Gd(3)]和{[Ln_4(1,3-bdc)_6(H_2O)_4(DMF)](DMF(2H_2O}_n[Ln=Er(4),Ho(5)](1,3-bdc:间苯二甲酸,DMF:N,N-二甲基酰胺)。通过单晶X射线衍射、红外光谱、紫外-可见-近红外(UV-Vis-NIR)光谱、荧光光谱等技术手段对产物的结构和性能进行了表征。结果表明,配聚物1~3是同构的,属单斜晶系,P2(1)/n空间群;配聚物4、5是同构的,属三斜晶系,P-1空间群。在晶体中,间苯二甲酸根采用多样的配位模式,使配聚物呈现多维的结构。除配聚物4,其余均呈现Ln(Ⅲ)的特征NIR发光,并与其UV-Vis-NIR吸收光谱相关联。  相似文献   

16.
《Liquid crystals》2001,28(2):279-285
Rare-earth complexes of mesomorphic Schiff 's bases, 4-[(alkylimino)methyl]-3-hydroxyphenyl 4-alkyloxybenzoates, were synthesized. Whereas the ligands LH display a nematic and/or a smectic C phase, the metal complexes show a viscous smectic A phase and decompose at the clearing point. The mesophase was investigated by hot-stage polarizing optical microscopy, by differential scanning calorimetry and by high temperature X-ray diffraction. Two types of complex were found, [Ln(LH)3 (NO3)3] and [Ln(LH)2L(NO3)2], depending on the ligand or the central metal ion. The first coordination sphere of the rare-earth ion in these metallomesogens is comparable to that in the structure of complexes with 4-alkoxy-N-alkyl2-hydroxybenzaldimine ligands.  相似文献   

17.
A new family of heteropolytungstate complexes (NH4)21[Ln(H2O)5{Ni(H2O)}2As4W40O140xH2O(Ln=Y, Ce, Pr, Nd, Sm, Eu, Gd) were prepared by the reaction of Na27[NaAs4W40O140]·60H2O with NiCl2·6H2O and Ln(NO3)3·xH2O at pH≈4.5. The crystal structures of (NH4)21[Gd(H2O)5{Ni(H2O)}2As4W40O140]·51H2O was determined by X-ray diffraction analysis and element analysis. The compound crystallizes in the monoclinic space group P21/n with a=19.754(3), b=24.298(4), c=39.350(6) Å, β=100.612(3)°, V=18564(5) Å3, Z=2, R1(wR2)=0.0544(0.0691). The central site S1 and two opposite sites S2 of the big cyclic ligand [As4W40O140]28− are occupied by one Ln3+and two Ni2+, respectively, each site supply four Od coordinating to metal ion, another one water molecule and other five water molecules coordinate, respectively, to Ni2+and Ln3+. Polyanion [Ln(H2O)5{Ni(H2O)}2As4W40O140]21− has C2v symmetry. IR and UV–vis spectra of [NaAs4W40O140]27− of the title compounds are discussed.  相似文献   

18.
在乙醇水溶液体系中合成了8种新的稀土吲哚-3-乙酸和吲哚-3-丁酸配合物,其通式为Ln(lA)3·2H2O和Ln(IB)3·2H2O(Ln=La,Nd,Sm,Er;IA=C10H8NO2;IB=C12H12NO2)。用元素分析、电导测定、电子吸收光谱、红外光谱、X光电子能谱和热重-差热分析确定了配合物的组成和成键特性。  相似文献   

19.
在酸性介质、含水溶剂中合成了四元混配化合物[Ln(BA)2(NO3)(phen)]2(BA=苯甲酸根;Ln=La,Ce,Pr,Nd,Sm,Eu,Dy,Gd,Tb,Er),用元素分析、IR、DTA-TG等方法对配合物进行了表征.研究了配合物的顺磁性能和荧光性能.镨配合物的单晶衍射结果表明,配合物属三斜晶系,双核,Pr3+的配位数为9,4个BA呈二种配位方式,丰富了四元配合物的结构表现形式.  相似文献   

20.
轻稀土硝酸盐及其水合物制备的研究   总被引:21,自引:1,他引:20  
在文研究了轻稀土硝酸盐及其水合物的几种制备途径,并研究了高水合物的干燥条件。提出了制取Ln(NO2)3·nH2O(Ln=La,Pr,Nd,Sm;n=6,5,4,2,1)和La(NO3)3的实验方法。  相似文献   

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