Encapsulation of Eu(TTA)(3) into MCM-41 mesoporous molecular sieve by sol-gel method

The rare earth complex Eu(TTA)(3) was successfully encapsulated into MCM-41 mesoporous molecular sieve by the addition of the complex into the sol-gel mixture for the synthesis of MCM-41 mesoporous material under microwave radiation. The as-synthesized MCM-41-hosted Eu(TTA)(3) mesophase was confirmed to possess hexagonally ordered mesostructure and a uniform crystal. size of about 30 nm with XRD and HRTEM techniques. Moreover, the IR spectrum, photoluminescence effect and fluorescence lifetime of the Eu(TTA)(3)/MCM-41 hybrid were also studied. An increase in Stokes' shift and no change in luminescence lifetime were observed to the resultant mesophase in comparison with Eu(TTA)(3) in ethanol solution.

An encapsulation of the rare earth complex in modified mesoporous molecular sieve MCM-41

The encapsulation of a rare earth (RE) complex Eu(DBM)(3)phen in modified S1-MCM-41 with 3-aminopropyltriethoxysilane is reported for the first time. The luminescence intensity of the RE complex in the modified Si-MCM-41 is about 9 times as strong as in unmodified Si-MCM-41 and the luminescence of the RE complex in the modified SI-MCM-41 has good color purity.

Eu(TTA)_3/MCM-41介孔复合体的溶胶凝胶法组装

利用溶胶 凝胶法将稀土配合物Eu(TTA) 3 组装到MCM 41介孔分子筛的孔道中 ,并初步认定客体分子Eu(TTA) 3 是以加合物形式包裹于表面活性剂胶束中。该法制得的介孔复合体Eu(TTA) 3/MCM 41,用XRD、HRTEM技术证实具有短程有序的、规整的六方介孔结构和大小分布均匀的纳米晶粒。对其光致发光和荧光寿命的研究发现 :与乙醇溶液中相比 ,Eu3 +的荧光寿命没有发生改变 ,但Stokes位移却明显增大 ;复合体中 ,能量是从主体MCM 41传递到客体Eu(TTA) 3 上。

Preparation, characterization and luminescent properties of MCM-41 type materials impregnated with rare earth complex

Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.

Encapsulation of fluorescein into MCM-41 mesoporous molecular sieve by a sol-gel method

MCM-41-hosted fluorescein mesophase was prepared by addition of the dye into the sol-gel mixture for the synthesis of MCM-41 mesoporous molecular sieve under microwave radiation. The as-synthesized organo-silica-surfactant material possessed hexagonal mesostructure with short-range symmetry and a uniform nanosize of about 30 nm. Furthermore, fluorescence spectrum, increase in lifetime and lack of aggregation at high concentration were discussed in terms of the effect of the host-guest interaction on these properties. (C) 2001 Published by Elsevier Science B.V.

新型无机-有机杂化中孔发光材料(phen)_2Eu/MCM-41的合成与表征

合成出了担载稀土有机配合物的无机 -有机杂化中孔发光材料 ( phen) 2 Eu/MCM-4 1 ,用 X射线衍射、红外光谱、荧光光谱和紫外 -可见漫反射光谱对所得样品进行了表征 ,并与相应的纯稀土配合物进行了比较 .结果表明 ,所得杂化材料具有典型的中孔材料 MCM-4 1的结构 ,且经组装后孔结构保持不变 ,在紫外光照射下 ,发出稀土离子的特征谱线 ,但与纯稀土配合物相比 ,其激发光谱发生蓝移 ,稀土 Eu3+ 所处的格位对称性降低 ,荧光寿命延长 .另外 ,对光谱性质进行了讨论 .

A novel catalyst for clean production of diphenols - Ferric trisacetylacetonate MCM-41

Ferric trisacetylacetonate has been deposited within the zeolite MCM-41 and the product characterized by XRD and IR. In water at pH 7 it catalyzes the oxidation of phenol by H2O2, giving 58% conversion in 1 h at 50 degrees C: products are catechol (66%), hydroquinone (27%) and benzoquinone (7%). Other oxidants and solvents are much less effective. UV-VIS spectra suggest a radical substitution mechanism, and a pollution-free process for phenol hydroxylation is now possible.

Iron(II)-8-quinolinol/MCM-41-catalyzed phenol hydroxylation and reaction mechanism

Iron(II)-8-quinolino/MCM-41 is prepared. Its catalysis is studied in phenol hydroxylation using H2O2 (30%) as oxidant. The experiment shows that Iron(II)-8-quinolinol/MCM-41 has good catalytic activity and desired stability. Based on cyclic voltammetry, ESR, and UV-visible spectra studies of iron(II)-8-quinolinol complex in liquid phase, a radical substitution mechanism is proposed and used to demonstrate the experimental facts clearly. (C) 1997 Academic Press.

八羟基喹啉铁(Ⅱ)/MCM-41对苯酚羟化的催化作用

利用ＭＣＭ－４１中孔分子筛为载体，制备了负载型八羟基喹啉铁（Ⅱ）／ＭＣＭ－４１（简记为Ｆｅ（Ⅱ）－Ｑｘ／ＭＣＭ－４１）催化剂．ＸＲＤ，ＩＲ证明八羟基喹啉铁（Ⅱ）配合物成功地负载于ＭＣＭ－４１分子筛中．考察了八羟基喹啉铁（Ⅱ）／ＭＣＭ－４１对苯酚羟化反应的催化作用，和未负载的配合物相比，苯酚的转化率、对苯二酚的选择性以及Ｈ２Ｏ２的利用率都有显著的提高．同时也探讨了温度、反应介质及介质ｐＨ值对苯酚羟化反应的影响．结果表明，随着温度的提高，苯酚的转化率增加，但温度太高，易导致副产物增多；有机溶剂不利于羟化反应的进行，水是实验条件下苯酚羟化反应的最佳反应介质；在一定程度上，ｐＨ值越低，越有利于反应活性的提高，若ｐＨ值太低，活性反而下降，ｐＨ值升高不利于苯酚羟化反应的进行．该催化剂也具有较高的稳定性.

Immobilization of the heteropoly acid (HPA) H4SiW12O40 (SiW12) on mesoporous molecular sieves (HMS and MCM-41) and their catalytic behavior

Supported catalysts, consisting of SiW12 immobilized on hexagonal mesoporous silica (HMS) and its aluminum-substituted derivative (MCM-41) with different loadings and calcination temperatures, have been prepared and characterized by X-ray diffraction, FT-IR and NH3-temperature programmed desorption. It is shown that SiW12 retains the Keggin structure on the mesoporous molecular sieves and no HPA crystal phase is developed, even at SiW12 loadings as high as 50 wt%. In the esterification of acetic acid by n-butanol, supported catalysts exhibit a higher catalytic activity and stability and held some promise of practical application. In addition, experimental results indicate that the loaded amount of SiW12 and the calcination temperatures have a significant influence on the catalytic activity, and the existence of aluminum has also an effect on the properties of supported catalysts.

Hydroxylation of phenol by iron(II)-phenanthroline(Phen)/MCM-41 zeolite

MCM-41 zeolite and Tron (II)-Phen/MCM-41 zeolite have been prepared and characterized by XRD, IR, NH3-TPD, HET and UV-Vis. The Iron( II)-Phen/MCM-41 zeolite+30% H2O2 system is capable for catalyzing hydroxylation of phenol.

Hydroxylation of phenol by iron(II)-phenanthroline(Phen) MCM-41 zeolite

MCM-41 mesoporous molecular sieve and iron(II)-Phen/MCM-41 have been prepared and characterized by XRD, IR, NH3-TPD, BET and UV-Vis. The iron(II)-Phen/MCM-41 molecular sieve + 30% H2O2 system is capable of performing hydroxylation of phenol.

铁1,10-菲咯啉/MCM-41催化苯酚羟化反应的研究

MCM-41分子筛是最近美国Mobil公司开发出的一种新材料,其孔径范围在2.0～25nm之间,具有较大的Si/Al比和大的比表面积及孔隙率,孔道大小均匀.其对弱极性的环状及芳族化合物具有较大的吸附能力.自这种新型分子筛合成以来,才开始应用于石油炼制及烯烃裂解,歧化的研究.至今还没有关于将MCM-41作为载体,用于负载金属配合物催化剂的报道.本文利用自己合成的MCM-41分子筛作为载体,制成了负载铁的1,10-菲咯啉配合物催化剂(简记FePhen/MCM-41),并将其应用于苯酚的羟化反应,发现其对苯酚的羟化反应具有较好的催化性能.1 实验部分1.1 FePhen/MCM-41的制备将参考文献[3]制得的MCM-41分子筛,取5g放入200mL0.05mol/L的[Fe(Phen)_3]Cl_2乙醇溶液中,室温搅拌24h,抽滤,所得固体用乙醇洗涤3次,以除去MCM-41分子筛表面和孔道内结合不牢的金属配合物.利用原子吸收光谱分析仪,测得负载催化体系中铁元素的含量为0.65%.1.2 MCM-41分子筛及FePhen/MCM-41的表征

小型桡足类种群动力学研究

小型桡足类在生态系统中的重要作用近年来得到了广泛的关注，在近岸生态系统中，小型桡足类起着相当重要的作用。但关于小型桡足类种群动力学的研究在国内还处于起步阶段，因此我们选取了国内沿岸海域常见优势种小拟哲水蚤、双刺纺锤水蚤、太平洋纺锤水蚤及强额拟哲水蚤等四种小型桡足类为研究对象，探讨其种群动力学相关方面的变动机制。本文在2005年10月－2006年9月选取胶州湾为主要的研究海域，进行了一周年的小型桡足类的采样和培养实验研究。在胶州湾，小拟哲水蚤（Paracalanus parvus）全年出现，其种群数量变动呈现双峰型，在夏季（6月和8月）达数量高值，在冬季（1月）有一个小的高峰。种群数量在4月达全年最低值，在7月份数量也有一个明显的数量降低。从空间分布上来讲，该水蚤在冬季主要以CV期桡足幼体存在于湾南和湾外区域，湾北数量很少；从春末开始，各期幼体开始在各海区广泛分布。小拟哲水蚤在胶州湾几乎全年产卵（2月份除外），但较高的产卵率主要集中在春末到秋初，最大产卵率出现在5月，达27.9 eggs female-1d-1。总体来讲，在胶州湾小拟哲水蚤的产卵率与温度、叶绿素及体长均呈显著正相关，但与盐度呈负相关关系。从不同的区域来看，胶州湾湾北区域小拟哲水蚤产卵率较高，最高值出现在湾北6月份，产卵率达到了60.8 eggs female-1d-1。大于10 eggs female-1d-1的产卵率在湾北持续了6个月（4－9月），在湾口持续了5个月（4－8月），而在湾外只持续了3个月（5－7月）。小拟哲水蚤生物量在6月份达到最高值（6.15 mg C m-3），在4月达到全年最低值（0.028 mg C m-3）。次级生产的变动从4月到9月与生物量的变动趋势完全相似，但冬季生物量的高峰并没有伴随次级生产的高峰值，分析其原因是由于冬季低的生长率所致。小拟哲水蚤在整个胶州湾平均的年次级生产为158.41 mg C.m-3yr -1。强额拟哲水蚤（Paracalanus crassirostris）在胶州湾只在夏末到秋季出现，最大数量出现在8月份。从强额拟哲水蚤的分布区域来看，从湾内到湾外有递减趋势。在2006年9月份，只有湾北有部分种群，其他区域几乎没有该种出现。该种最大产卵率出现在8月，达11.2 eggs female-1d-1。强额拟哲水蚤生物量的变动与次级生产的变动趋势相似，最大值也都出现在8月份。该水蚤在胶州湾平均年次级生产仅为2.12 mg C m-3yr-1。双刺纺锤水蚤(Acartia bifilosa)在胶州湾是全年出现，其种群数量在5－6月份突发性增加达全年最高值（>8000 ind. m-3），之后又急剧下降。从该种的区域分布来看，5－6月份数量的高峰主要出现在湾北区域，7月份虽然各区域数量均下降，但大部分种群集中在湾外区域。双刺纺锤水蚤在胶州湾几乎全年产卵（1－2月除外），产卵率的最高值出现在4月，达16.5 eggs female-1d-1。4月份雌体高的产卵率为5月份种群数量的大量增加提供了补充。双刺纺锤水蚤生物量与次级生产的变动趋势一致，在5－6月份达到高值，在秋冬季次级生产较低。双刺纺锤水蚤在整个胶州湾平均的年次级生产为114.61 mg C m-3yr-1。太平洋纺锤水蚤（Acartia pacifica）在胶州湾季节性出现，在冬春季节消失，从夏季开始出现。该种在5月零星出现，种群数量在6月份开始增多，到7月份达到最高值2356 ind. m-3，之后在8月数量锐减至196 ind. m-3。从区域分布来看，该水蚤在胶州湾只出现在湾北和湾南区域，湾外区域几乎没有，而且呈现湾北到湾南递减的趋势。6月份数量大部分出现在湾北区域，到7月份才有一部份在湾南出现。太平洋纺锤水蚤在其出现季节均产卵，最大产卵率出现在6月份，达37.17 eggs female-1 d-1，部分补充了7月份太平洋纺锤水蚤种群数量的大量增加。太平洋纺锤水蚤生物量与次级生产的变动趋势相似，在7月份达到了最高值，在11月达到最低值。太平洋纺锤水蚤在胶州湾平均的年次级生产为45.63 mg C m-3yr-1。胶州湾四种小型桡足类总的年次级生产为~320 mg C m-3 yr-1。

Synthesis and characterization of manganese-modified MCM-41

Manganese-modified mesoporous MCM-41 molecular sieves were synthesized at the absence of alkaline metal ions under mild alkaline condition using cetylpyridinium bromide surfactant as a template, and characterized with X-ray diffraction, N-2 adsorption, transmission electron microscopy, electron spin resonance (ESR), and nuclear magnetic resonance (NMR) spectroscopies. The synthesized MnMCM-41 has a high pore volume of 1.30 cm(3) g(-1) with a corresponding surface area of 1510 m(2) g(-1). The ESR and Si-29 MAS NMR spectra revealed the presence of framework manganese ions in either the as-synthesized or calcined forms. (C) 2002 Elsevier Science B.V. All rights reserved.