Synthesis of oligo(p-phenylene vinylene)-porphyrin-oligo(p-phenylene vinylene) triads as antenna molecules for energy transfer

The oligo(p-phenylene vinylene)-porphyrin-oligo(p-phenylene vinylene) (P-OPVn, n=2, 4, where n is the number of phenyl rings) and the complex with Zn²⁺ based on P-OPVn were synthesized for investigating their photophysical properties via UV-vis, voltammetry, steady-state and time-resolved fluorescence spectra. In these molecules two OPV moieties as energy donors were linked to porphyrin center by virtue of Wittig reaction. The detailed studies of photophysical properties indicate that OPV group can act as an antenna unit for effective intramolecular energy transfer.     

草酰胺桥联大环二羰四胺铜(Ⅱ)-钴(Ⅱ)异双核配合物的合成、结构、表征和电化学性质

合成了一种具有草酰胺桥联大环二羰四胺结构的 Cu( ) -Co( )异双核配合物 ,用红外光谱、电子光谱、摩尔电导、热重分析、室温磁矩、循环伏安等对其进行了表征 .初步推定 Cu( ) -Co( )异双核配合物具有草酰胺桥联大环二羰四胺结构 .室温磁矩测定表明 ,通过草酰胺桥联配体金属离子间有一定的反铁磁性自旋偶合作用 .循环伏安法测定了配合物的半波电位 ,实验表明 ,此类配合物能够稳定高价态 Cu( ) ,外延桥基配位对大环内腔 Cu( )离子的氧化还原过程无影响 .单核配合物 X射线晶体衍射研究表明 ,其为单斜晶系 ,空间群 P2 1 /c,a=0 .73 861 (1 5 ) nm,b=2 .1 2 1 1 (4 ) nm,c=0 .95 2 5 0 (1 9) nm,β=94.70 (3 )°,R1 =0 .0 5 1 3 ,w R2 =0 .1 1 77,Z=4.Cu( )处于大环四胺平面正方中心上方 0 .0 3 nm,并具有外延草酰胺桥     

PHOTODESTRUCTION OF BACTERIORHODOPSIN

Abstract— Suspensions of purple membrane fragments showed obvious signs of degradation after illumination with intense pulses of light from 10 ns frequency doubled Nd: YAG laser at 532 nm with intensity densities in excess of 1 MW/cm². Using controlled illumination, a small fraction of the bacteriorhodopsin protein molecules were randomly destroyed in samples with a low salt concentration (12.5 m M ) and pH = 7.9. Calculations using information from the changes in the optical absorbance spectrum and transient changes in the optical absorbance spectrum during the photocycle support a model where one protein molecule of the bacteriorhodopsin trimer is photodestroyed, the other two protein molecules switch to a blue state . In the blue state , the protein molecules have a red shifted absorption, with a peak near 600 nm. The blue state molecules show transient absorption changes at 656 nm that are similar to the native bacteriorhodopsin, except the O state is missing or altered. Additionally, the changes in curvature of the purple membrane fragments that occur during the photocycle of intact protein molecules are severely depressed. The addition of salts to the photodestroyed suspension can change the blue state molecules back to a state with an absorption maximum at 568 nm. The salt ions probably shield the other members of the trimer from the photodestroyed protein. In these reconstituted samples, the O state is observed at 656 nm; however, the membrane bending is not observed.     

Investigation of the Interaction Between N-benzyl Piperidones and Bovine Serum Albumin by Spectroscopic Approaches

Fluorescence and ultraviolet spectroscopies were applied to investigate the interaction between five N-benzyl piperidones (NBP) and bovine serum albumin (BSA) under imitated physiological conditions. The experimental results show that these NBPs have a static fluorescence quenching effect on the endogenous fluorescence of BSA at the temperatures 302 and 310?K. According to the fluorescence quenching theory, the Stern?CVolmer quenching constant (K _SV), the binding constant (K _a), and the number of binding sites (n) were obtained. Also, the effect of substituents on the binding capacity between NBP and BSA is in the order: C₆H₅?<?4-CH₃OC₆H₄?<?4-CH₃C₆H₄?<?2,4-Cl₂C₆H₃?<?4-ClC₆H₄. The corresponding thermodynamic parameters (??G, ??H, and ??S) were obtained at two different temperatures and indicate that hydrogen bonding and van der Waals forces play main roles in stabilizing the BSA?CNBP complex. The binding distance between the tryptophan residue in BSA and NBP was found to be much <7?nm based on the F?rster theory of non-radiation energy transfer. The effect of NBP on the conformation of BSA was analyzed as well by synchronous fluorescence spectroscopy.     

One ligand capable of in situ reaction in a mixed-ligand system with two new different frameworks

The in situ ligand 2,3-pyrazinedicarboxylic acid (2,3-H₂pzdc) mixed with 1,1′-(1,4-butanediyl)bis(benzimidazole) (bbbi) is used to form two coordination polymers ([Cd(2,3-pzdc)(bbbi)] (1) and [Cd₂Cl₃(2-pzc)(bbbi)₂] (2)) under hydrothermal conditions. Complex 1 was obtained in the absence of in situ reaction and 2 was synthesized with 2,3-H₂pzdc in situ generating 2-pyrazinecarboxylate (2-pzc^?). The structural details reveal that 1 has a 3D framework with dia topology, and 2 is a 2D layer structure and develops a 3D supramolecular structure via strong π?π stacking interactions. The ligand effects were compared for the two frameworks. In addition, fluorescence properties and thermal stabilities of 1 and 2 in the solid were studied.     

cis-[（trans-1，2-双（氨甲基）环丁烷）（3-羟基-1，1-环丁烷二羧酸根）合铂（Ⅱ）]的合成和抗癌活性

通过对洛铂和卡铂的结构进行重组和优化,合成了一种新型洛铂衍生物cis-[（trans-1,2-双（氨甲基）环丁烷）（3-羟基-1,1-环丁烷二羧酸根）合铂（Ⅱ）],采用元素分析、红外光谱、质谱和核磁共振表征了其化学结构,并考察了此化合物的水溶性和稳定性。应用标准SRB法测试了目标化合物对人肺癌细胞株（NCI-H460、A549）、人乳腺癌细胞株（DU4475）、人白血病细胞株（Sup-B15）生长的抑制活性,评价了它对人肺癌细胞NCI-H460裸鼠移植瘤的治疗作用。结果表明：目标化合物水溶性好、稳定,对多种癌细胞的生长有明显的抑制活性,IC₅₀均小于10 μmol·L^-1。更重要的是,其体内对人肺癌细胞NCI-H460裸鼠移植瘤的治疗效果明显,与洛铂相当。     

烷氧基菲咯啉设计合成及其氮磷杂配铜光敏剂的光解水制氢性能

以功能化氮配体为导向,以4,7-二苯基-1,10-菲咯啉为原料,经季铵化、氧化、卤化和醚化合成了一类新型的2,9-二烷氧基-4,7-二苯基-1,10-菲咯啉配体5a~5e。再以Xantphos为膦配体,通过原位配位方法合成一系列氮磷杂配铜光敏剂（CuPS A~H）,在均相光解水制氢体系中研究其光敏活性。制氢结果表明,以2,9-二乙氧基为较佳取代基,CuPS D的催化产氢总转换数（TON）可达270。在光电物理性能分析中,发现这类杂配铜配合物都有一个相似的氧化还原电位（E^oxd=-0.8 V,E^red=-1.2 V）。具有乙氧取代基的铜配合物CuPS D相对于其他取代基的铜基配合物,荧光最弱,表明乙氧基有助于提高荧光淬灭效率,增强铜光敏剂的光化学转换能力。     

溶胶凝胶辅助水热可控合成ZnO不同形貌分级结构光催化剂

以Zn(NO₃)₂·6H₂O、柠檬酸和NaOH为原料,采用溶胶凝胶(sol-gel)辅助水热法,仅通过改变水热时间,就可得到片花、棒花及梭状3种不同形貌ZnO分级结构。利用XRD、SEM、UV-Vis DRS、光致发光光谱(PL)和氮低温吸附-脱附等手段对合成的ZnO样品进行了表征。推测了合成条件下不同形貌ZnO分级结构形成的机理。以活性翠兰(KGL)为模拟印染废水,考察了其光催化活性。结果表明,虽然所合成的不同形貌的ZnO样品在光照120 min后均能使KGL降解78%以上,但其中水热4 h得到的片花状ZnO光催化性能最好,可降解99%的KGL,这与其片花状的形貌、较大的比表面积、较多的表面氧缺陷和极性面有关。     

电化学生物传感器在环境监测中的应用及发展前景

简要介绍了电化学生物传感器的工作原理,重点论述了电化学生物传感器在环境监测领域的应用及其研究进展,主要包括水环境污染物和大气污染物的监测,以及农药残留的监测等.同时,对电化学生物传感器的发展方向及前景进行了展望.     

Synthesis of Dispiro[indole‐3,2′‐pyrrolidine‐3′,2″‐pyrrolizine]‐1″,2(1H)‐diones via Azomethine Ylide 1,3‐Dipolar Cycloaddition

The 1,3‐dipolar cycloaddition of azomethine ylide generated in situ from isatin and sarcosine to 2‐arylmethylidene‐2,3‐dihydro‐1H‐pyrrolizin‐1‐ones afforded novel 1′‐methyl‐4′‐(aryl)‐1″H‐dispiro[indole‐3,2′‐pyrrolidine‐3′,2″‐pyrrolizine]‐1″,2(1H)‐diones in good yields. The structures of all the products were characterized thoroughly by NMR, infrared spectroscopy, mass spectrum, and elemental analysis.