铽β-二酮配合物复合离子凝胶的合成及其发光性质的研究

离子凝胶是一种将离子液体固定在Si-O基质凝胶材料中的新型离子液体固态材料。首先通过溶胶-凝胶法合成均匀透明的离子凝胶材料,然后利用离子液体这一良好溶剂及其在凝胶材料中的可循环性,通过提取离子液体及再吸附稀土铽配合物与离子液体的溶液,实现铽配合物在离子凝胶材料中均匀稳定的掺杂。合成了两种铽β-二酮配合物复合离子凝胶材料并研究材料光致发光性能,发现复合材料中铽配合物保持了Tb(Ⅲ)的特征发射,其荧光寿命在复合材料中略变短,该复合材料方法简单,合成条件温和且环保,材料的合成为稀土配合物的应用提供了又一类新型复合材料。     

两步溶胶-凝胶法于SiO2/聚合物杂化基质中原位合成铕的三元配合物及其发光性质

采用两步溶胶－凝胶过程制备了含铕的三元配合物的凝胶。荧光激发光谱证实于ＳｉＯ２基质中原位合成了铕的配合物。含铕配合物的杂化材料发出铕的特征荧光，与相应的纯配合物溶于乙醇相比，铕离子具有较长的荧光寿命。     

二甲基甲酰胺存在下溶胶-凝胶法于TiO_2基质中原位合成铕三元配合物及发光性质

在二甲基甲酰胺存在下, 采用溶胶凝胶法于ＴｉＯ２ 基质中原位合成了铕ＴＴＡＰｈｅｎ 三元配合物, 此结果并由荧光激发光谱和红外光谱得到证实。含铕配合物的ＴｉＯ２ 凝胶发出铕的特征谱线, 且与相应的纯配合物溶于乙淳中相比, 具有较长的荧光寿命。考察了掺杂浓度对发光强度的影响。     

一种有机酰腙类配体及其金属凝胶的结构及性能

设计合成了一种带有长链烷基和配位基团的新型有机配体2-吡啶甲醛-4'-十二烷氧基苯甲酰腙(简称L),并采用核磁(1H-NMR)、红外(FTIR)、电喷雾质谱(ESI-MS)和元素分析确认其结构.在乙醇和水的混合溶剂中,配体L可使溶剂凝胶化,并可与多种金属离子(Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ)和Cu(Ⅱ)作用,形成金属凝胶.采用扫描电镜分析表明,L自身形成的凝胶及金属凝胶的微观形貌均为相互搭接的纤维状结构.采用紫外光谱分析表明在乙醇溶液中L分子形成了聚集体.采用平板流变仪分析表明引入金属离子可提高凝胶的强度.进一步合成了L与Cu(Ⅱ)的配合物,通过对比配合物与金属凝胶的红外光谱和紫外光谱,证明金属凝胶中配体L与金属离子间形成了配位作用.     

掺Eu及Ag微粒的SiO2凝胶在多孔阳极氧化铝中的荧光增强

近年来,将稀土配合物掺杂于溶胶－凝胶（Sol-gel)基质中及在溶胶－凝胶制备过程中原位（In stitu)合成稀土配合物已有报道^[1]。溶胶－凝胶基质使掺杂分子和外界隔绝,形成一种很好的保护基质,而渗杂的光活性物质,由于受到笼效应的影响,掺杂分子之间相互孤立,减小了聚集体的生成和浓度猝灭^[2]。在溶胶－凝胶中掺杂镧系离子,尤其掺杂Eu^2 和Sm^2 等二价离子已成为研究热点,它们在光学存储^[3]、固态激光^[4]、绿光发光材料、药物学上的X射线无机发光材料等方面具有潜在应用前景。二价镧系离子（如Eu^2 ）通常是由三价离子（Eu^3 ）在加热条件下,经短波光还原或电化学还原产生的,而在溶胶－凝胶中既可有效地还原Eu^3 ,也可将Eu^2 固定在光学透明凝胶中^[5]。国内有关凝胶中掺杂稀土离子的荧光现象虽报道很多^[6],但将凝胶固定在多孔基底上却未见报道。多孔阳极氧化铝具有规则的六边形孔状结构,还可以根据需要制成不同的形状,在其为模板制备金纳米线^[7],由于溶胶可渗入几个至十个纳米深的孔道中,在多孔基底上用溶胶－凝胶法制作的薄膜能增强荧光现象并没有较好的重现性。     

溶胶-凝胶法制备稀土铽配合物掺杂的发光薄膜

采用溶胶－凝胶法原位制备了稀土配合物掺杂的发光薄膜，薄膜透明均一。结果表明用原位合成法，可以将难溶性稀土羧酸类配合物有效地掺杂到溶胶基质中，荧光光谱分析表明，所得到的薄膜材料在紫外激发下发射出铽离子的特征发射线。     

微凝胶增强两性复合水凝胶的制备与性能

将核壳微凝胶包埋在两性基质中,制备了复合水凝胶(CAH)。 研究发现,利用微凝胶与聚合物链之间的物理缠结作用,可以使复合凝胶具有致密的网络结构,力学性能显著提高;复合凝胶对pH和离子强度敏感,呈现出典型的两性聚电解质凝胶的溶胀行为。 同时微凝胶的存在和特殊的复合结构,可赋予CAH两性凝胶基质所不具有的响应性,并实现在高温下快速响应。     

SiO2凝胶中间甲基苯甲酸铕-邻菲罗啉配合物的热稳定性及发光性能

溶胶-凝胶法(sol-gel)以其温和的反应条件和灵活多样的操作方式成为制备新型荧光材料的合适方法,它可以在低温下制备均匀掺杂光学活性物质的高熔点氧化物玻璃,为无机玻璃在激光、非线性光学技术领域的应用开拓了新的思路,也为许多新型光学材料的应用开发和改良提供了新的途径.很多稀土有机配合物具有很好的发光性能,但因其热稳定性较差而限制了它们的实际应用.近年来已有含稀土二元配合物凝胶发光性能的研究报道[1～4],本文采用溶胶-凝胶法将铕-间甲基苯甲酸-邻菲罗啉三元配合物引入SiO2基质中制成新的透明复合发光材料,对其热稳定性和发光…     

测定高分子聚合物-金属配合物稳定常数及平均配位数的新方法

建立了基于化学平衡理论模型以及凝胶过滤色谱(GFC)-电感耦合等离子体质谱(ICPMS)联用技术的高分子聚合物-金属配合物稳定常数、平均配位数测定新方法。以聚乙烯亚胺(PEI)和Cu2+为例,对形成的PEI-Cu配合物稳定常数、平均配位数进行测定,以0.02 mol·L-1 HAc-NaAc为流动相,凝胶色谱柱分离大分子PEI-Cu配合物以及Cu的小分子配合物、游离态离子,最后用ICPMS测定不同形态金属元素的浓度;利用建立的化学平衡理论模型,计算PEI与金属离子形成配合物的稳定常数、平均配位数,测得25℃,pH4.1~5.3时,PEI-Cu配合物稳定常数为109.6~1010.7,平均配位数为1.0~1.3。建立的在线分离、测定方法具有快速、准确的特点,为高分子聚合物-金属配合物的研究提供新的技术手段。     

SiO2凝胶中铕（铽）—间甲基苯甲酸—邻菲呤啉配合物的热稳定性及发光性能研究

采用溶胶－凝胶法,以掺杂方式制备了含有铕（铽）－间甲基苯甲酸－邻菲咯啉配合物的SiO2凝胶复合发光体,研究了其热分解曲线,激发光谱和发射光谱,并与固体粉末进行了比较,讨论了将配合物引入该凝胶后对其热稳定性及发光的影响。     

Preparation et etude des proprietes complexantes de polycondensats contenant des diazapolyoxamacrocycles dans la chaine principale

Some diazapolyoxamacrocycles have been polycondensed with different difunctional compounds to give polymers and gels. Their synthesis and their complexing properties towards alkali metals and calcium cations are reported.     

Complexation behaviour of radiation synthesized poly(vinylbenzyltrimethylammonium chloride) and its gel with potassium hexacyanoferrates (II, III) and potassium persulfate in aqueous medium

High energy gamma radiation has been used to synthesize linear poly(vinylbenzyltrimethylammonium chloride) (PVBT) as well as crosslinked PVBT gels. Complexation behaviour of linear and crosslinked PVBT with K₂S₂O₈, K₃[Fe(CN)₆] and K₄[Fe(CN)₆] have been studied by viscometry, turbidity and equilibrium swelling measurements. The stoichiometry of the complex formed was found to be a function of charge on the anions of complexing species. Crosslinked poly(vinylbenzyltrimethylammonium chloride) gels were found to desorb some of the embedded water when swollen gels were placed in these salt solutions. Existence of strong ionic interactions between polymer chains and complexing salts was confirmed by changes in equilibrium swelling of complexed crosslinked matrices as well as in the stoichiometry of linear PVBT complexes in presence of strong electrolytes like NaCl.     

Preparation and evaluation of a novel chiral stationary phase based on covalently bonded chitosan for ligand-exchange chromatography

A novel chiral stationary phase based on chitosan covalently bonded onto silica gels has been prepared and used for the separation of various alpha-amino acid enantiomers as well as alpha-hydroxycarboxylic acid enantiomers by chiral ligand-exchange chromatography with copper(II) as a complexing ion. The methanol content and copper(II) ion concentration in the eluent affected retentivity and enantioselectivity. Furthermore, a plausible chiral recognition mechanism for resolution of alpha-amino acids was proposed.     

The drawing behavior of Y-Ba-Cu-O sol from non-aqueous solution by a complexing process

A complexing process is developed to prepare Y-Ba-Cu-O superconducting fibers. The process is not identical to typical sol-gel processes; here the resulting gel network is built up by hydrogen bonding linkage among complexing species in non-aqueous solution. Cu acetate, [Cu(OAC)₂], Ba methoxyethoxide [Ba(ORE)₂] and Y acetate [Y(OAC)₃] are used as precursors for preparing homogeneous gels while -methacrylic acid (HOAA) and diethylenetriamine (DETA) as complexing agents, and methoxyethanol (REOH) as solvent. Fibers drawn from a sol obtained through reduced pressure present no or little deformation at 80°MoC via adjusting the amount of DETA and HOAA. Cu(OAC)₂, Ba(ORE)₂ and Y(OAC)₃ in the complexing process have been demonstrated to form gels without hydrolysis and condensation at ambient atmosphere. The relationships between the drawing behavior of sols and gel structure with different amounts of DETA and HOAA are suggested. The concentration region of drawing the gel fibers with no or little deformation heated at 80°MoC is also found.     

Nano-biomachine from actin and myosin gels

We introduce here an ATP (adenosine triphosphate)-fueled nano-biomachine constructed from actin and myosin gels. Various types of chemically cross-linked actin gel, which are tens of times larger in size than native actin filaments (F-actin), were formed by complexing with cation-polymers and placed on a chemically cross-linked myosin gel. By adding dilute solution of ATP, they moved along the myosin gel with a velocity as high as that of native F-actin by coupling to ATP hydrolysis. Formation mechanism and structure of actin complexes as well as those of myosin gels were studied in detail and elucidated with the specific characteristics of the motility. These results demonstrate that one can construct nano-biomachines fueled by chemical energy of ATP with controlled motility. The text was submitted by the authors in English.     

Use of New Chiral Hydrophilic Gels dor the Direct Resolution α-Aminoacids by High Pressure Liquid Chromatography

Abstract

Total resolution of α-aminoacids was achieved by H P L C using porous gels based on acrylamide grafted with chiral substituents (L-α aminoacids) and complexed with metal ions.

We discuss the influence of the structure of the gel (porosity, hydrophilicity and coordination affinity), of the kinetics of the ligand exchange, of the nature of the complexing ion and of the chiral graft.     

Novel anion receptors: hybrid materials based on quaternary ammonium salts for selective extraction of dichromate ions

Novel hybrid materials were obtained by modification of three (poly)amine-appended mesoporous silica gels. For all matrices of different side chain lengths, the process proceeded with excellent modification rates. The free analogues of these hybrid materials, podand-type receptors, were also prepared employing a very similar procedure. The organosilicas synthesized were characterized by NMR, infrared spectroscopy, and semi-empirical methods. Their anion exchange properties were conveniently investigated using precise, but also time and cost-efficient titration experiments, and the products were found to be powerful complexing agents for dichromate ions.     

Preparation and Optical Characterization of Organoeuropium-Doped Silica Gels

Gels have been investigated as potential matrices for rare earth luminescence. The use of complexing ligands in the sol-gel synthesis of the rare-earth doped glasses has been suggested to improve the rare earth ion luminescence properties in these matrices due to the changes in the local environment experienced by the rare earth ion. In this work, transparent Eu3+-doped gels were prepared from Si(OCH3)4 and fluorinated and/or complex-forming Eu3+ precursors (Eu(fod)3, (CF3 SO3)3Eu, (CF3CO2)Eu · 3H2O, Eu(thd)3 and Eu(acac)3). Results of emission, fluorescence line narrowing and lifetimes studies of Eu3+-doped gels derived from Si(OCH3)4 and fluorinated/chelate Eu3+ precursors are presented. The results were interpreted in terms of the evolution of the Eu3+ fluorescence in systems varying from solutions to the gels densified to 800°C. Analysis of the fluorescence decays of the 5D0 state suggests that the use of the fluorinated Eu3+ precursors reduces the hydrophobic content in the silica gels matrices. FLN studies indicate that Eu3+ clustering occurred in all densified samples.     

A new way to prepare tin oxide precursor polymeric gels

Transparent tin oxide gels are elaborated in the isopropoxide/toluene/isopropanol system. The gelation occurs at room temperature without any acid or base additions. The formation of the SnO₂ precursor gels polymeric network is evidenced by Fourier transform infrared spectroscopy. The gelation time is studied as a function of the complexing ratio R = [acac]/[Sn(OR)₄], the hydrolysis ratio W = [H₂O]/[Sn(OR)₄], the concentration of tin oxide precursor C = [Sn(OR)₄], and the volume fraction of toluene P = (toluene volume) / (total solvent volume).     

Synthesis and characterisation of copper(II) hydroxide gels

The formation of copper(II) hydroxide gels from aqueous precursors requires very critical conditions. Gels have been obtained by adding ammonia to aqueous solutions of copper(II) acetate, in the presence of a small amount of sulphate ions. Other salts (chloride, nitrate, sulphate) or bases (NaOH, KOH) lead to precipitation rather than gelation. These gels are actually made of an intimate mixture of acetate-based organic/inorganic polymers and nanometric posjnakite crystals Cu₄(OH)₆(SO₄) · H₂O. Acetate ions and ammonia can be partially removed upon washing, which after drying leads to crystalline copper(II) hydroxide needles deposited on a strongly oriented layer of posjnakite crystals. A theoretical model based on the electronegativity equalisation principle is used to describe these experimental results. It provides a better understanding of the role of complexing anions during the formation of condensed phases.