稀土与染料的相互作用

本文用可见吸收光谱、核磁共振谱、红外光谱等分析方法,研究了Nd、Eu与阳离子染料、酸性染料、活性染料及直接染料之间的相互作用。结果表明稀土与大多数染料之间没有形成稳定的配合物,在中性或酸性条件下与含磺酸基的染料之间只形成磺酸盐,与含羧酸基的染料之间形成羧酸盐。只有与酸性媒介染料之间形成稳定的配合物,其结构与铬及其配合物相似。     

低能离子与生物有机小分子相互作用机制的初步研究

利用低能离子束(N^+,Ar^+离子)辐照固态羧酸钠(甲酸钠)、(乙酸钠)、(苯甲酸钠)和固态嘧啶碱基两类样品,经电子顺磁共振谱(EPR)、富里叶红外光谱(FT-IR)的检测,结果发现,三种低能离子辐照后的甲酸钠样品中产生了[COO]^.^-自由基和亚甲基(CH2),氮离子辐照乙酸钠和苯甲酸钠样品后,形成了新的化学基团氰基(CN);同时,结合茚三酮反应,证明了辐照后的羧酸钠和碱基样品中还含有新的基团氨基(NH2),给出了氨基的产生量与注入离子的剂量的相关曲线。     

聚酰胺胺树状大分子与Cu2+相互作用的研究

研究了聚酰胺胺树状大分子的代数、4．0代聚酰胺胺树状大分子与Cu^2＋摩尔比、溶液的pH值、反应时间和温度对4．0代聚酰胺胺树状大分子与Cu^2＋相互作用的影响。结果表明当聚酰胺胺树状大分子存在时,配合物水溶液的最大吸收波长出现了蓝移。当4．0代聚酰胺胺树状大分子和Cu^2＋摩尔比由1：10变为1：30时,配合物水溶液在610nm处出现新的吸收主峰,并且发生红移。当溶液的pH值降到3．0左右时,4．0代聚酰胺胺树状分子不能与Cu^2＋络合,Cu^2＋被释放出来,这为聚酰胺胺树状分子的循环使用提供了理论依据。温度升高可使配合物的吸收光谱在可见光区的强度增加,但时间对配位体系影响很小。     

树枝状尼龙6的合成与研究

用单羧基封端的尼龙6分别与树枝状聚酰胺-胺(PAMAM)的G1代和G2代外围活泼氨基进行缩聚反应,合成出具有规整结构的由核心向外发散增长的树枝状尼龙6,采用红外光谱、扫描电镜、DSC和TGA对缩聚物进行了分析。     

热处理对尼龙6及其与聚酰胺嵌段共聚物共混体系晶体熔融行为和结晶结构的影响

采用溶液共混-共沉淀的办法获得尼龙6及聚酰胺嵌段共聚物/尼龙6共混体系粉末,样品在260℃下熔融之后经程序降温的方法得到非淬火样品,然后分别在190℃下高温退火不同时间(0~48 h),采用示差扫描量热仪(DSC)、广角X射线衍射仪(WAXD)、偏光显微镜(POM)等表征手段研究热处理对体系晶体熔融行为和结晶结构的影响.结果表明,(1)在相同的热历史条件下,嵌段共聚物的存在影响了尼龙6的结晶行为及结晶结构;(2)退火处理对两种样品有着不同的影响,对于尼龙6体系,退火处理促进了非晶相向晶相的转变,大大提高样品的结晶完善程度和结晶度;对于共混体系,退火处理同样促进了非晶相向晶相的转变,同时形成新的α型和γ型结晶,体系的结晶完善程度明显提高,退火48 h后,结晶度比原始样品提高约84%.     

聚酰胺-胺树状高分子与稀土离子络合的荧光光谱研究

合成了4.0代聚酰胺-胺(PAMAM)树状分子,用荧光分光光度法研究了4.0代PAMAM树状分子与Sm3 、Dy3 、Ce3 的络合作用.结果表明,反应时间、PAMAM物质的量、反应体系pH都会影响PAMAM对Ce(Ⅲ)、Sm(Ⅲ)及Dy(Ⅲ)离子的配位作用,对端氨基树状高分子主要存在RE-N4和RE-N2两种配位方式;随着稀土离子的加入,各种配位方式的相对比例会发生变化;pH对配位方式也有较大的影响.该研究为制备尺寸可控的PAMAM树状高分子封闭的稀土原子簇提供了理论基础.     

稀土离子及其配合物与磷脂脂质体的相互作用

用核磁共振(NMR)方法研究了稀土离子及其配合物与二棕榈酰磷脂酰胆碱(DPPC)和鞘磷脂(SPM)脂质体的相互作用.磷脂极性头平行于膜平面.稀土离子与磷脂极性头P—O键键合,与经典模型不同,键合后极性基团仍平行于膜平面,而不是垂直于膜平面.稳定的稀土配合物对磷脂脂双层结构影响很小.将稀土离子引入磷脂脂质体和小分子配体的混合物中,稀土首先与小分子配体配位.     

土壤中腐殖酸与稀土离子作用的傅里叶变换红外光谱

采用NaOH碱提法提取和纯化了黑土中胡敏酸（humic acid,HA)用傅里叶变换红外光谱（FTIR）研究了HA与La^3 、Ce^3 、Cd^3 和Y^3 4种稀土离子作用前后的光谱特征。结果表明,HA与稀土离子作用后的红外光谱中归属于COO^-1600cm^-1、1400cm^-1处的振动吸收峰增强,表明腐殖酸与稀土离子之间发生了配合作用。     

稀土离子特性与稀土功能材料研究进展

稀土元素是一个包含了由钪、钇与镧系共17种元素的系列统称,它们既具有本质上的物理化学相似性,也具有各自独特和多样的电子结构。 从化学水平上讲,稀土离子的特性决定了稀土永磁、磁致冷、超导、热释电、光学制冷、非线性光学、催化等高新技术应用的本质;从材料水平上讲,稀土功能材料是实现这些技术应用的基础。 从科技发展要求来讲,稀土功能材料的研发是实现稀土资源高质量发展的最重要途径。 本文从稀土离子特性出发,利用轨道杂化模型构建稀土离子与稀土功能材料之间的基本关系,总结了近年来不同应用领域中稀土离子在稀土功能材料的组成设计与性能优化方面的研究进展。     

姜黄素及其改性产物与皮胶原作用研究

我国使用天然染料历史悠久,但随着近代化学工业的发展,出现了合成染料,合成染料以其丰富多彩的色彩和优良的染色牢度而得以广泛应用,天然染料则受到冷落.     

谷胱甘肽与衡土离子作用的13^C NMR研究

本文利用顺磁稀土离子的诱导化学位移变化的性质, 研究了多官能团配体谷胱甘肽(GSH)与稀土的配位作用。在水溶液中GSH通过分子两端的羧基负离子与稀土形成遥爪配位结构。谷氨酸和甘氨酸羧基与Eu^3+的配位稳定常数分别为12.5±0.1L.mol和100.0±0.5L/mol。从13^C化学位移的pH变化曲线求得谷氨酸和甘氨酸羧基解离的pK~a值分别为2.20±0.02和3.50±0.04。对Dy^3+、Ho^3+、Er^3+、Tm^3+和Yb^3+作用下, GSH的13^C位移数据分析表明, 配体与这些离子形成同构的配合物, 分子两端羧基均可能以双齿形式与稀土配位。     

Thermal Decomposition Studies of Mixed Rare Earth Hydrogen Selenite Crystals

Mixed rare earth hydrogen selenite crystals, neodymium praseodymium hydrogen selenite (Nd_xPr_1−x(HSeO₃)(SeO₃)⋅2H₂O), Neodymium samarium hydrogen selenite (Nd_xSm_1−x(HSeO₃)(SeO₃)⋅2H₂O) and praseodymium samarium hydrogen selenite (Pr_xSm_1−x(HSeO₃)(SeO₃)⋅2H₂O) were prepared by gel diffusion technique. Simultaneous thermogravimetric and differential thermal analysis were carried out on the grown crystals. Decomposition is observed to occurs in six steps, which gives the evidence of successive losses of H₂O and SeO₂. The final product due to decomposition is a mixed rare earth oxides. FT-IR spectrum of the crystal samples heated at different temperatures complemented to the TG-DTA results. This revised version was published online in July 2006 with corrections to the Cover Date.     

Optically hybrid lanthanide ions (Eu3+, Tb3+)‐centered materials with novel functional di‐urea linkages

The synthesis of 3‐(triethoxysilyl)‐propyl isocyanate (TEPIC) modified by (3‐aminopropyl)triethoxysilane (APS) and the preparation of the corresponding organic–inorganic molecular‐based hybrid material with the two components equipped with covalent bonds is described. The coupling agent moiety is a convolution of TEPIC and APS through ? NHC(?O)NH? groups, which is applied to coordinate to RE³⁺ and further formed Si? O backbones after hydrolysis and polycondensation processes. For comparison and luminescence efficiency purposes, we added 2,2‐bipyridyl to the above hybrids in order to increase the conjugating effects and sensitize rare earth ions emissions. Luminescence spectra were utilized to characterize the photophysical properties of the hybrid material obtained, and the above spectroscopic data reveal that the triplet energy of 2,2‐dipyridyl in this favorable hybrid system matches with the emissive energy level of RE³⁺. In this way, the intramolecular energy transfer process took place within these molecular‐based hybrids and strong green and red emissions of RE³⁺ have been achieved. Copyright © 2005 John Wiley & Sons, Ltd.     

Interaction between spin-labelled penicillins and lanthanide ions

The penicillin (1b) [spin-labelled with a nitroxide group] has been prepared by reacting 6-amino-penicillanic acid (1e) with 3,5-dibromo-4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl (2). Penicillin (1b) is a potential probe for proteins (e.g. penicillinases) which bind penicillins. Because it is intended to use paramagnetic metal ions as additional probes in studies of proteins with (1b), an investigation has been carried out of the interactions of (1b) and the related ester (1d) with a series of lanthanide ions. It is shown that a direct interaction between the nitroxide group of (1b) [or (1d)] and the metal ion leads to contact quenching of the EPR spectrum of (1d).     

镧系元素对Pd/Al2O3的修饰及其与丙烯腈气相加氢的关联

用浸渍法制备了镧系元素(Ce,La,Sm)修饰的低负载Pd(0.05 w.t%)/A l2O3催化剂,并应用于丙烯腈选择性加氢反应,实验结果表明:这种方法制备的催化剂对丙烯腈具有很好的选择性,镧系元素的添加大大促进了催化剂的活性和稳定性。XRD的测试结果表明稀土元素铈的添加减弱了Pd和载体A l2O3之间的相互作用,从而导致了Pd从载体表面游离出来。从TEM照片上可以看出催化剂颗粒尺寸的变化。XPS的测试结果表明用镧系元素修饰的Pd的结合能向较高能级发生了转移,从而使得钯被还原为零价。     

稀土元素与NEB二元配合物的pH电位法分析

氨三乙氧基三苯甲酸(ＮＥＢ)(ＮＥＢ·ＨＣｌ的分子结构式见下图)作为有立体选择性的配体,它与铀酰离子ＵＯ2(Ⅱ)配位作用已有报导[1]。在对ＮＥＢ质子化常数及二元体系Ｍ(Ⅱ)-ＮＥＢ·ＨＣｌ(Ｍ=Ｃｄ、Ｃｏ、Ｎｉ、Ｃｕ和Ｚｎ)配合物的稳定常数测定的基础上[2],本文在25℃及离子强度为0 2ｍｏｌ/ＬＫＮＯ3的条件下,用精密ｐＨ电位法考察二元体系ＲＥ(ＩＩＩ)—ＮＥＢ(ＲＥ=Ｌａ→Ｎｄ,Ｓｍ→Ｌｕ,Ｙ)中存在的配合物物种及其稳定常数。ＮＥＢ·ＨＣｌ结构式1　实验部分1 1　试剂和仪器ＮＥＢ·ＨＣｌ(Ｈ3Ｌ·ＨＣｌ,Ｌ3-=Ｃ27Ｈ24ＮＯ9)…     

The interaction of Co ions and sodium deoxycholate micelles

To mimic the interaction between divalent metal ions and bile slats in vivo, two groups of coordination complex compounds, crystalline and gel-like, were synthesized in vitro by mixing the aqueous solutions of CoCl₂ with sodium deoxycholate (NaDC) at various concentrations. Structures and compositions of the compounds were investigated using FT-IR, EXAFS, XRD as well as elemental and ICP analysis, respectively. Then the interaction of Co²⁺ with deoxycholate in solution was observed by laser light scattering (LLS), Transmission electronic microscope techniques and ICP analysis. Conclusions are (1) the crystalline complexes, Co (DC)₂·3H₂O were obtained by reaction of Co²⁺ with mono-molecules of NaDC, and the gel-like complexes, Na_nCo_m(DC)_n+2m formed by reaction of Co²⁺ with NaDC micelles. The gel-like complexes exhibit the non-stoichiometric character; (2) the coordination structures of carboxyl groups with Co²⁺ were different between the crystalline and gel-like complexes. In Co(DC)₂·3H₂O complex, the carboxyl groups of deoxycholate coordinated with Co²⁺ in chelating and pseudo-chelating modes, but that in bridge mode in the case of Na_nCo_m(DC)_n+2m complexes. The non-stoichiometric complexes of Na_nCo_m(DC)_n+2m are formed with a macromolecular structure through the Co²⁺ bridges; (3) NaDC can increase the solubility of Co(DC)₂·3H₂O in aqueous solution, and larger micelles (30-80 nm diameter) formed in the supernate. It is a mixed micelle formed by Co²⁺ ions bridges connecting with NaDC simple micelles. So these micelles are a new kind of micelle containing two kinds of metal ions; (4) these results are in agreement with those formed under physiological conditions in that the different states such as gel, precipitate, micelles of various structures are present in bile of gallbladder. An ideal model of the interaction between Co²⁺ and bile salts in vivo has been proposed.