聚丁二酸丁二酯/纳米高岭土共混体系结晶及力学性能研究

用熔融共混法制备聚丁二酸丁二酯(PBS)/纳米高岭土(nano kaolin)复合降解材料,利用FTIR、DSC、万能拉力机和SEM对其微观结构、结晶、力学性能及分散性进行研究.FTIR光谱分析结果表明,改性剂与nano kaolin发生了化学键合作用;DSC结果表明,在PBS中加入nano kaolin,提高了结晶起...     

A novel calixsalen macrocycle: metal sensing behavior for Zn2+ and intracellular imaging application

The chiral [3+3] macrocycle 1 which displays a calixarene-like crystal structure has been synthesized. The UV/Vis and fluorescence spectral studies show that 1 and Zn²⁺ have a 1:3 complex stoichiometry. It exhibits high selectivity toward Zn²⁺, but no significant responses toward other competitive cations. The intracellular imaging ability has been tested in HeLa cells using a confocal microscope.     

Salen-based chiral fluorescence polymer sensor for enantioselective recognition of α-hydroxyl carboxylic acids

(R,R)-Salen-based chiral polymer P-1 was synthesized by the polymerization of 5,5'-((2,5-dibutoxy-1,4-phenylene)bis(ethyne-2,1-diyl))bis(2-hydroxy-3-(piperidin-1-ylmethyl) benzaldehyde (M-1) with (1R,2R)-cyclohexane-1,2-diamine (M-2) via nucleophilic addition- elimination reaction, and (R,R)-salan-based polymer P-2 could be obtained by the reduction reaction of P-1 with NaBH(4). (R,R)-Salen-based chiral polymer P-1 can exhibit greater fluorescence enhancement response toward (l)-α-hydroxyl carboxylic acids, and the value of enantiomeric fluorescence difference ratio (ef) can reach as high as 8.41 for mandelic acid and 6.55 for lactic acid. On the contrary, (R,R)-salan-based chiral polymer P-2 shows obvious fluorescence quenching response toward α-hydroxyl carboxylic acids. Most importantly, (R,R)-salen-based polymer P-1 can display bright blue fluorescence color change in the presence of (l)-α-hydroxyl carboxylic acids under a commercially available UV lamp, which can be clearly observed by the naked eyes.     

Coumarin-based chiral fluorescence sensor incorporating a thiourea unit for highly enantioselective recognition of N-Boc-protected proline

New coumarin-based chiral thiourea sensor 1 was found to be an enantioselective fluorescent chemosensor for N-Boc-protected proline. The chiral sensor shows lower background fluorescence, and higher fluorescence enhancement with 18 nm blue shifts. Job plot analysis result indicates that sensor 1 can form a 1 : 1 stoichiometric complex and it could be used as a fluorescence sensor for the determination of enantiomer composition of N-Boc-protected proline.     

An In Situ Generated Achiral Cu(II)‐Containing Polymer Complex Sensor for Enantioselective Recognition Induced from L‐/D‐Histidine Enantiomers

A novel achiral polymer P‐1 is synthesized by the polymerization of (2,5‐bis(octyloxy)‐1,4‐phenylene)diboronic acid ( M‐1 ) with pyridine‐2,6‐diylbis(methanylylidene)bis(4‐iodoaniline) ( M‐2 ) via Pd‐catalyzed Suzuki coupling reaction. The tridentate ligand in the main chain backbone can further coordinate with Cu²⁺ to afford the corresponding achiral copper‐containing polymer complex P‐2 , which selectively responds to L‐/D‐histidine with significant fluorescence enhancement over other amino acids. Interestingly, P‐2 exhibits obvious CD response toward L‐ or D‐histidine compared with its model compound MC , indicating that this kind Cu(II)‐containing polymer complex sensor can be used as an effective chemosensor for enantioselective recognition of histidine enantiomers by means of CD spectroscopy.

     

Novel fluorescent sensor for Ag and Hg based on the BINOL-pyrene derivative via click reaction

A novel BINOL-pyrene derivative sensor 1 for Ag⁺ and Hg²⁺ incorporating the triazole moieties and pyrenes was synthesized via click reaction. Binding of Ag⁺ ion induces the formation of 1:1 Ag⁺-1 chelating complex, and occurs in a ratiometric manner through an enhanced monomer and declining excimer emission, which make it possible to ratiometrically detect Ag⁺. The competitive experiment shows 1 can be used as an Ag⁺ specific fluorescence sensor over a wide range of competing cations. In the meanwhile, the sensor 1 was found to be selectively quenched by only Hg²⁺ at both monomer and excimer emission. Furthermore, we obtained evidences for different fluorescence signaling behaviors with Ag⁺ and Hg²⁺ by ¹H NMR titration experiments.     

双核钯配合物Pd2L2和Pd2L2X2(L=Me2PCH2PMe2;X=F,Cl,Br,I,H)的量子化学理论研究

采用 ab initio HF,MP2方法和密度泛函理论方法,对Pd(0),Pd(Ⅰ)双核配合物Pd2L2和Pd2L2X2(L=Me2PCH2PMe2;X=F,Cl,Br,I,H)的儿何结构和电子结构进行了研究.研究表明Pd2L2中Pd原子间的相互作用丰要来自电子相关效应,Pd2L2X2中Pd原子问的相互作用则主要来自d轨道的成键作用.MP2方法和局域泛函Xa方法能对两类配合物的几何结构给予准确的描述.在Pd2L2中,Pd原子的4d电了组成一一对应的成键、反键轨道,轨道作用相互抵消使Pd原子间仅存在微弱的相互作用.x原子与Pd2L2的作用使Pd-Pd反键轨道电子占据数减少,成键作用加强.两类配合物的Pd-Pd键长与NAO键级之间存在很好的线性关系.还对Pd2L2和Pd2L2X2的低占据电子激发态进行了含时密度泛函理论计算,分析不同配合物的电子跃迁特征,并就卤素配体对Pd2L2X2光谱性质的影响进行了讨论.     

微波诱导等离子体原子吸收光谱法测定Mg,Pb,Zn的研究

微波诱导等离子体(MIP)应用于原子吸收光谱法(AAS)起始于1970年,当时由于灵敏度不高,加之是在减压条件下工作,因而未能引起人们的重视。1988年,本室采用常压Ar—MIP作为AAS的原子化器,用电热进样的方法测定了Cu、Ag、Pb等元素,获得了较好的结果。Ng等人采用气功雾化的进样方法,用MIP—AAS测定了Cu、Mn、Ca等元素,其特征浓度在μg/ml水平。本文是在上述研究的基础上,改用超声雾化方法将样品引入MIP中,用水冷凝和浓H_2SO_4吸收相结合的方法去溶,研究了对Mg、Pb和Zn的测定,并用于实际样品分析,取得了较好的结果。     

乙苯脱氢Fe_2O_3－K_2O系催化剂中晶格氧和钾的助催作用

采用程序升温还原反应（ＴＰＲ）、ＸＰＳ、高温真空ＸＲＤ及活性和比表面测定等方法对单组分Ｆｅ_２Ｏ_３、双组分Ｆｅ_２Ｏ_３－Ｋ_２Ｏ催化剂及工业用ＸＨ－０３催化剂研究晶格氧的性质和钾的助催作用；结果表明，纯Ｆｅ_２Ｏ_３催化剂表面氧种的还原程度差别较大，反应时晶格氧易于失去，造成缺氧而迅速失活，钾的加入使催化剂生成新的Ｋ_２Ｆ_ｅ２Ｏ_４相，其表面氧种的还原性趋向一定的温度范围，晶格氧数量增加，且其稳定性也增加，从而同时促进了氧转移脱氢和直接脱氢反应的活性，因此认为Ｋ_２Ｆｅ_２Ｏ_４可能是活性相，脱氢反应的活性中心应由Ｆｅ~（２＋）、Ｆｅ~（３＋）、还原程度一定的晶格氧和Ｋ~＋组成。     

希土(Ⅲ)噻吩甲酰三氟丙酮和BipyO_2/PhenNO三元配合物的合成和表征

希土（Ⅲ）噻吩甲酰三氟丙酮和ＢｉｐｙＯ２／ＰｈｅｎＮＯ三元配合物的合成和表征成义祥徐端钧徐元植（浙江大学化学系，杭州３１００２７）关键词：希土三元配合物噻吩甲酰三氟丙酮荧光光谱希土与氟代β二酮配合物不仅能提高配合物的分子内能量传递量子产额，同时也...