双冠醚研究(Ⅴ)——Schiff碱型和仲胺型双-(苯并-18-冠-6)对碱金属苦味酸盐的萃取性质

用两类结构不同的Schiff碱型、仲胺型双-(苯并-18-冠-6)在氯仿-水体系中对碱金属苦味酸盐进行萃取,测量了配合物组成比和萃取平衡常数。     

Ion-pair extraction of uranyl ion from aqueous medium using crown ethers

Ion-pair extraction behaviour of uranyl ion from aqueous solutions was studied at pH 3.0 employing crown ethers viz. benzo 15 crown 5 (B15C5), 18 crown 6 (18C6), dibenzo 18 crown 6 (DB18C6), and dibenzo 24 crown 8 (DB24C8) in chloroform as the organic phase and picric acid as the organophilic counter anion. The stoichiometry of the extracted species corresponded to [UO₂(crown ether)_n]²⁺·[pic⁻]₂ where n=1.5 for benzo 15 crown 5 and 1 for 18 crown 6 as well as dibenzo 18 crown 6. Adducts of DB24C8 could not be observed as practically no extraction was possible using this reagent. The separation behaviour of fission products from an irradiated uranium target was also studied. An interesting observation on the separation of trivalent lanthanides from uranyl ion is reported.     

Synthesis and Characterization of Two [2]Catenanes Based on Phenylene-diacetylene Crown Ethers

Two charged donor-acceptor [2]catenanes were synthesized by the cyclization of the π-acceptor 1,1 ＇-[1, 4-phenylenebis-（methylene）]bis（4,4＇-bipyridinium）bis（hexafluorophosphate）（2） and bis（bromomethyl）benzene with the templates of the π-donor phenylene-diacetylene crown ethers la and lb in the yields of 31%, 35%, respectively. The mass spectra, 1H and 13C NMR spectra confirm that the phenylene-diacetylene crown ethers, with a nonaromatic ~r-system, successfully template the cyclization of CBPQT4＋. The X-ray crystallography analysis shows that the CBPQT4＋ ring encircles around the phenylene motif of the crown ethers, leaving the 1,3-butadiyne fragment out of the cavity of CBPQT4＋ ring. The mechanically interlocked structure of [2]catenanes was stabilized by the cooperative effects of π-stacking and hydrogen bonding interactions.     

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⁼。     

含二苯酮基光敏性冠醚的研究

光敏冠醚、苯甲酰苯井-15-冠-5(BPC)和双(4-苯并-15-冠-5)甲酮(CBPC),用光谱方法和动力学方法进行了研究,吸收光谱和发射光谱数据表明,BPC和CBPC的最低激发态具有ππ^*特性,它们的光化学性质和烷氧基取代的二苯酮相似,在紫外光照射下,BPC和CBPC很容易和叔胺进行光反应生成自由基碎片,光还原过程用吸收光谱测定进行了跟踪,这些光敏冠醚BPC和CBPC,配合叔胺可用作烯类光聚合的引发剂,测得的聚合速度(R_p)和[BPC]^0.17[TEA]^0.29及[MMA]^0.81成正比。     

Synthesis and fluorescence behaviour of crown and azacrown ethers carrying the dansyl fluorophore as a pendant in acetonitrile solution

The influence of Li⁺, Na⁺, K⁺, Cs⁺, Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Pb²⁺ and Al³⁺ ions on the spectroscopic properties of the dansyl group covalently linked to crown ether or diazacrown ethers was investigated by means of absorption and emission spectrophotometry. Interaction of the alkali metal ions with all fluoroionophores studied is weak, while alkaline earth metal ions interact strongly causing about 50% quenching of dansyl fluorescence of A21C5-Dns and A₂18C6-Dns. The Cu²⁺, Pb²⁺ and Al³⁺ cations interact very strongly with dansyl chromophore regardless the crown ether type, causing a major change in absorption spectrum of the chromophore and forming non-fluorescent complexes. The Co²⁺, Ni²⁺, Zn², Mg²⁺ and Ag⁺ cations interact moderately with all fluoroionophores studied causing about 20% of fluorescence quenching of dansyl, except for a strong dansyl fluorescence quenching of 15C5-Dns by Co²⁺ ion. The quenching efficiency of didansylated fluoroionophores by the alkali metal ions and alkaline earth metal ions is weaker than monodansylated ones.     

Cleavage of different ether bonds in butyl glycidyl ether and allyl glycidyl ether by K, K(15-crown-5)2

The kind of substituent in alkyl glycidyl ethers affects the course of their reaction with K⁻, K⁺(15-crown-5)₂. The cyclic oxirane ring is exclusively cleaved in the case of butyl glycidyl ether whereas the presence of the unsaturated allyl group in the glycidyl ether molecule unexpectedly prefers the scission of the linear ether bond. In both the systems organometallic intermediates are formed. They react with crown ether causing its ring opening. Allylpotassium formed from allyl glycidyl ether reacts also with another glycidyl ether molecule; the oxirane ring is opened in this case.     

Dissociation characteristics of [M + X]+ ions (X = H,Li, Na,K) from linear and cyclic polyglycols

The unimolecular reactions of protonated and metalated polyglycols with kiloelectronvolt translational energies have been studied by collisionally activated dissociation and neutralization-reionization mass spectrometry. The former method provides information on the ionic dissociation products, whereas the latter allows for the identification of the complementary neutral losses. Protonated linear polyglycols mainly undergo charge-initiated decompositions that lead to eliminations of smaller oligomers. On the other hand, protonated crown ethers (“cyclic” polyglycols) favor charge-induced reactions that proceed by cleavages of two ethylene oxide units in the form of 1,4-dioxane. Replacement of one O by NH in the crown ether dramatically changes its unimolecular chemistry; now, charge-remote 1,4-eliminations from ring-opened isomers are preferred. Charge-remote reactions are also the major decomposition channels of all metalated precursors studied. The linear polyglycols decompose primarily by 1,4-H₂ eliminations and to a lesser extent by homolytic cleavages near chain ends. The reverse is true for metalated crown ethers, which preferentially produce distonic radical cations by the loss of saturated radicals; these reactions are proposed to involve prior rearrangement to open-chain isomers. The nature of the metal ion (Li⁺, Na⁺, or K⁺) does not greatly affect the unimolecular chemistry of the cationized polyglycol. In general, metalated precursors form many abundant fragment ions over the entire mass range; hence, collisional activation of such ions at high kinetic energy should be particularly useful for structure elucidations.     

冠醚化合物对乳剂晶体外延生长的调变作用

本工作研究了冠醚化合物在外延乳剂生长过程中的调变作用。结果表明,1,4,7,10,13,16-六氧杂环十八烷对AgBr八面体乳剂无侵蚀作用,对非同晶系晶体之间的外延不起调变作用。1,7,10,16-四氟-4,13-二氮代杂环十八烷均使AgBr八面体乳剂的棱角产生了不同程度的侵蚀,可充当不同晶系晶体外延生长的调变剂,对晶体的溶解侵蚀能力依2S-18-C-6,2N-18-C-6,18-C-6的次序降低。这与它们同Ag⁺络合能力的强弱一致。2S-18-C-6,2N-18-C-6仅对非同晶系晶体之间的外延起调度作用,而对同晶系晶体的外延不起调查作用。冠醚化合物对晶体外延生长的调变作用与冠醚化合物对晶体的络合溶解作用有关。     

Synthesis of tripodal aza crown ether calix[4]arenes and their supramolecular chemistry with transition-, alkali metal ions and anions

Tripodal aza crown ether calix[4]arenes, 5a, 5b, 6a and 6b, have been synthesized. The structure of protonated 5a was elucidated by X-ray crystallography to be a self-threaded rotaxane. Complexation studies of 5a and 5b towards anions using Na⁺ as countercation were carried out by ¹H NMR titration in dimethylsulfoxide-d₆ and the mixture of chloroform-d and methanol-d₄, respectively. Ligands 5a and 5b were able to form 1:1 complexes with Br⁻, I⁻ and NO₃⁻ and the complexation stability varied as follows: NO₃⁻>I⁻>Br⁻. The effect of countercation on anion complexation was also investigated. The results showed that the association constants of 5a towards Br⁻ in the presence of various cations varied as K⁺>Bu₄N⁺>Na⁺. The enhancement in anion complexation ability of 5a may result from the rearrangement of the tripodal ammonium unit in the presence of K⁺. The neutral forms, 6a and 6b, were able to form complexes with transition metal ions such as Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺. The stability of the complexes followed the sequence: Ni²⁺2+Cu²⁺Zn²⁺. Compounds 6a and 6b may, therefore, potentially be used as either transition metal ion or anion receptors that can be controlled by pH of the solution.     

冠醚对生物化学影响的研究(Ⅲ)——五种冠醚化合物对小麦幼苗根系吸收与运转42K、24Na、45Ca离子的影响

本文用放射性同位素⁴²K、²⁴Na、⁴⁵Ca作示踪,配以P^K、P^Na离子选择电极测量溶液的电导率和电位变化。研究五种冠醚化合物对南大八号小麦幼苗根系吸收与运转无机离子(K⁺、Na⁺、Ca^艹)的作用。实验结果表明,五种冠醚化合物对小麦幼苗根系具有不同程度的促进吸收和加速运转K⁺、Na⁺、Ca^艹的作用,其中以1号冠醚化合物作用最为明显,在K⁺、Na⁺、Ca⁺艹>中对K⁺的作用最为突出。     

Cation-π Interactions:Synthesis and Crystal Structure of Complex:[Na(DB18C6)]2[Pd(SCN)4]

The cation-π interactions have attracted much attention as an important noncovalent binding force. We have synthesized and characterized the first example[K(DB 18C6)]₂[Pd(SCN)₄] which exist K⁺-π interactions in crown ether compounds^[1]. However,the reported Na+ complexes structurally characterized by X-ray diffraction analysis have so far been limited to a few compounds. We now report the structure of complex:[Na(DB18C6)]₂[Pd(SCN)₄] which also exist Na⁺-n interactions.     

Conformational analysis of 12-crown-3 and sodium ion selectivity of electrodes based on bis(12-crown-3) derivatives with malonate spacers

A conformational analysis was performed on two crown ethers (12-crown-3 and 12-crown-4) using a combination of semi-empirical and ab initio methods. The lowest conformations of 12-crown-3 and 12-crown-4 were found to have exodentate C_3v and C₂ structure, respectively. In the case of the sandwich-type complexation, the nucleophilic cavity of 12-crown-3 rather than that of 12-crown-4 seemed to be optimal for complexation with the Na⁺ ion. Four new bis(12-crown-3) derivatives (1–4) were examined as potential sodium ion-selective ionophores in poly(vinylchloride) (PVC) membrane electrodes. The ion-selective electrode (ISE) based on di(1,5,9-trioxacyclododecanylmethyl) 2-dodecyl-2-methylmalonate (1) had the highest selectivity for the sodium ion among the alkali and alkaline earths studied. The sodium ion selectivity of the ISE based on bis(12-crown-3) derivative 1 was superior to that of the ISE based on the bis(12-crown-4) analogue.     

冠醚化合物的合成——ⅩⅣ.二茂铁硫冠醚的合成及其银离子选择电极的研究

本文合成了两种类型6个二茂铁硫冠醚1—6,其中4—6是一类新型缩醛硫冠醚。将冠醚2—6作为传感活性物质研制成PVC膜银离子选择电报,其中以用冠醚4的电极性能最佳,对一价和二价干扰离子的选择性,远优于文献[1]结果。     

一种冠醚金属卟啉化合物的合成及其阴离子识别机制

本文合成了一种金属冠醚卟啉化合物并提出了一种基于该化合物的阴离子识别机制,为阴离子的可视化识别提供了一种简便的思路。     

4-甲基苯并-15-冠-5对某些镧系放射性核素的萃取

本文研究了4-甲基苯并-15-冠-5三氯甲烷溶液从苦味酸水溶液中对某些镧系放射性核素(¹⁴⁴Ce、¹⁴⁷Nd、^152+154Eu、¹⁷⁰Tm和¹⁶⁹Yb)的萃取。从斜率分析得出,被萃取状态为1:2:3(金属离子/冠醚/苦味酸根)络合物。在25℃,测定了三价镧系元素的苹取常数(K_ex),得到下列次序:Nd³⁺>Eu³⁺>Ce³⁺>Tm³⁺>Yb³⁺。结果表明,Nd³⁺的离子大小(r=0.995)比其它镧系元素可能更接近4-甲基苯并-15-冠-5环孔的大小。 为了将镧系元素与锕系元素作比较,还测定了4-甲基苯并-15-冠-5对Th⁴⁺、UO₂²⁺和Am³⁺的萃取率,所得到的萃取率次序为Th⁴⁺>Am³⁺UO₂²⁺。实验证明,4-甲基苯并-15-冠-5将可能是溶剂萃取法分离铀和钍的有用试剂。 溶剂和添加剂影响萃取实验表明,在有机相添加正丁醇或异戊醇,或者以高极性的溶剂(例如,硝基苯)替代三氯甲烷,都能显著地增加对镧系元素的萃取。     

Simultaneous separation of common mono- and divalent cations on silica gel modified with aluminium by non-suppressed ion chromatography with conductimetric detection and nitric acid–15-crown-5 as eluent

The modification of silica gel with aluminium by a coating method was very effective for the preparation of silica-based stationary phases which acted as a cation exchanger under strongly acidic conditions. However, the separation of common mono- and divalent cations (Li⁺, Na⁺, NH₄⁺, K⁺, Mg²⁺ and Ca²⁺) on an aluminium-adsorbing silica (Al-Silica) column was moderate by a conductimetric detection ion chromatography (IC) with strongly acidic eluents. Then, the addition of various crown ethers (12-crown-4, 15-crown-5 and 18-crown-6) in acidic eluent was carried out. As a result, it was found that 15-crown-5 was most effective for the improvement of peak resolution. Excellent separation of these cations was achieved in 20 min by elution with 2 mM nitric acid–2 mM 15-crown-5. The proposed IC was successfully applied to the determination of major cations in various natural waters.     

Aldol-type reactions between trimethylsilyl enol ethers and acetals with the aid of rhodium complex

Aldol-type reactions of trimethylsilyl enol ethers with acetals, ketals, and orthoesters are successfully performed with the aid of a catalytic amount of rhodium complex, Rh₄(CO)₁₂ or [Rh(COD)(DPPB)]⁺ClO₄⁻, underneutral conditions.     

Synthesis of new indolyl crown ethers catalyzed with ferric hydrogensulfate

Efficient reaction of bis-indolyl podand with different aldehydes using Fe（HSO₄）₃ as catalyst to afford the corresponding new indolyl crown ethers is described.The structures of three distinct isomers have been optimized using HyperChem geometry optimizations.Also percentage of each isomer was obtained with ¹H NMR spectroscopy.     

Synthesis and chemistry of the bis(trimethylsilyl)amido bis-tetrahydrofuranates of the group 2 metals magnesium, calcium, strontium and barium. X-ray crystal structures of Mg[N(SiMe3)2]2·2THF and related Mn[N(SiMe3)2]2·2THF

Transamination reactions utilizing the compound mercuric bis(trimethylsilyl)amide, Hg{N(SiMe₃)₂}₂, in tetrahydrofuran (THF), and the metals Na, Mg, Ca, Sr, Ba and Al have been investigated. Thus the THF solvated compounds Na[N(SiMe₃)₂]·THF and M[N(SiMe₃)₂]₂·2THF, M = Mg, Ca, Sr and Ba (1–4), have been prepared. The X-ray crystal structures of 1 and the related manganese compound Mn[N(SiMe₃)₂]₂·2THF (5) are reported. Interaction of the silylamides, 2–4, with a range of crown ethers apparently proceeded with elimination of silylamine, (Me₃Si)₂NH, and novel ring opening of the crown ethers, generating species containing a donor alkoxide ligand with a vinyl ether function, presumably, ---O(CH₂CH₂O)_nCH=CH₂ (n = 3−5). The silylamides 2–4 were also cleanly converted to the corresponding alkoxides (from ¹H NMR data) in reactions with stoichiometric quantities of 3-ethyl-3-pentanol.