异硫氰酸荧光素后修饰的金属有机三元环光解水制氢（英文）

将具有N、O、P三齿配位点的直线型双臂席夫碱配体L1与钴离子配位自组装得到一例[3+3]金属-有机三元环Co-L1。在该配体的苯环侧链上引入易于修饰的NH2基团,通过组装后修饰的方法把光活性的异硫氰酸荧光素(FITC)分子以共价键方式键合到金属-有机三元环上,并将其用于可见光下的光解水制氢。该体系属于无须引入额外光敏剂的双组分放氢体系。与传统的三组分体系相比,在同等金属催化剂和光敏剂浓度下,组装后修饰的金属配合物催化剂Co-L3具有更高的光催化活性,转换数(TON)可以达到80,大约是Co-L1光催化效率的30倍。     

修饰NADH模拟物的金属-有机三元环光催化制氢（英文）

将含有不同还原型烟酰烟腺嘌呤二核苷酸(NADH)活性中心模拟物的有机配体H_2L~1和H_2L~2与钴离子配位自组装获得2例具有氧化还原活性且带有正电荷的金属-有机大环Co-L~1和Co-L~2。选择阴离子型钌基光敏剂[Ru(dcbpy)_3]~(4-)(dcbpy=2,2′-联吡啶-4,4′-二羧酸)作为光敏中心,金属-有机大环结构作为质子还原催化剂,通过静电作用力将光敏中心封装在其空腔内部以加速光诱导电子转移(PET)过程,构建了人工光合成体系并应用于光解水制氢研究。相比于未修饰NADH模拟物的金属-有机大环Co-L~3以及未修饰NADH模拟物但配位环境相同的单核催化剂Co-L~4,由Co-L~1和Co-L~2构建的金属-有机大环主客体超分子体系的光催化产氢效率分别提高1.6和6倍,可能是由于NADH活性中心模拟物的引入以及主客体超分子体系的形成有利于光敏中心与催化中心之间的光致电子转移过程。     

修饰NADH模拟物的金属-有机三元环光催化制氢

将含有不同还原型烟酰烟腺嘌呤二核苷酸(NADH)活性中心模拟物的有机配体H₂L¹和H₂L²与钴离子配位自组装获得2例具有氧化还原活性且带有正电荷的金属-有机大环Co-L¹和Co-L²。选择阴离子型钌基光敏剂[Ru(dcbpy)₃]^4-(dcbpy=2,2′-联吡啶-4,4′-二羧酸)作为光敏中心,金属-有机大环结构作为质子还原催化剂,通过静电作用力将光敏中心封装在其空腔内部以加速光诱导电子转移(PET)过程,构建了人工光合成体系并应用于光解水制氢研究。相比于未修饰NADH模拟物的金属-有机大环Co-L³以及未修饰NADH模拟物但配位环境相同的单核催化剂Co-L⁴,由Co-L¹和Co-L²构建的金属-有机大环主客体超分子体系的光催化产氢效率分别提高1.6和6倍,可能是由于NADH活性中心模拟物的引入以及主客体超分子体系的形成有利于光敏中心与催化中心之间的光致电子转移过程。     

基于非贵金属镍的金属有机大环的光解水放氢性能

将具有NN（氮氮）双齿配位点的席夫碱配体L2（L2=1,4-苯二-2''-吡啶腙）与镍构筑得到一例[2+2]型金属有机大环[Ni₂（L2）₂（CH₃CN）₄]（ClO₄）₄·4CH₃CN（2）,并将其用于可见光条件下的光解水产氢研究。该非贵金属光催化体系由催化剂、光敏剂（荧光素,Fl）和电子牺牲剂（三乙胺）三部分组成。相比于具有相同配位环境的单核配合物[Ni（L1）₂（CH₃CN）₂]（ClO₄）₂（1,L1=3-甲酰基苯-2''-吡啶腙）,金属有机大环2作为催化剂具有较高的光催化活性,其产氢TON值可以达到3 100 mol_H2·mol_cat^-1,归因于荧光素分子可能与金属有机大环2形成超分子配合物,提高了光致电子转移效率。     

基于非贵金属镍的金属有机大环的光解水放氢性能

将具有NN(氮氮)双齿配位点的席夫碱配体L2(L2=1,4-苯二-2′-吡啶腙)与镍构筑得到一例[2+2]型金属有机大环[Ni_2(L_2)_2(CH_3CN)_4](ClO_4)_4·4CH_3CN(2),并将其用于可见光条件下的光解水产氢研究。该非贵金属光催化体系由催化剂、光敏剂(荧光素,Fl)和电子牺牲剂(三乙胺)三部分组成。相比于具有相同配位环境的单核配合物[Ni(L_1)_2(CH_3CN)_2](ClO_4)2(1,L1=3-甲酰基苯-2′-吡啶腙),金属有机大环2作为催化剂具有较高的光催化活性,其产氢TON值可以达到3 100 molH_2·molcat-1,归因于荧光素分子可能与金属有机大环2形成超分子配合物,提高了光致电子转移效率。     

利用钴-氨基硫脲类配合物作为氧化还原催化剂光分解水制备氢气

通过将磷配体与氨基硫脲结合进一步增加螯合配体的配位能力,并引入磺酸根增强其水溶性,合成了一个钴配合物Co-NSP(配体HNSP:4-[2-(2-二苯基膦-苯烯基)-氨基硫脲腙] 苯甲酸),利用其氧化还原特性开展均相体系的光驱动从水中制备氢气的研究.新的NSP三齿配体能够稳定低价的金属中心,有助于提升催化剂的催化性能.利用其与荧光素所构筑的光催化体系,在电子牺牲剂三乙胺存在下显示出良好的性能,光照6 h其TON(turnover number)可达2 000 mol H₂每摩尔催化剂.为了研究和比较其性能特点,对这一光催化体系的 荧光滴定和氧化还原性能也进行了较细致的研究.     

利用钴-氨基硫脲类配合物作为氧化还原催化剂光分解水制备氢气

通过将磷配体与氨基硫脲结合进一步增加螯合配体的配位能力,并引入磺酸根增强其水溶性,合成了一个钴配合物Co-NSP(配体HNSP:4-[2-(2-二苯基膦-苯烯基)-氨基硫脲腙]苯甲酸),利用其氧化还原特性开展均相体系的光驱动从水中制备氢气的研究。新的NSP三齿配体能够稳定低价的金属中心,有助于提升催化剂的催化性能。利用其与荧光素所构筑的光催化体系,在电子牺牲剂三乙胺存在下显示出良好的性能,光照6h其TON(turnover number)可达2000molH₂每摩尔催化剂。为了研究和比较其性能特点,对这一光催化体系的荧光滴定和氧化还原性能也进行了较细致的研究。     

双核三螺旋铁配合物的合成和结构

本文选择了2-羟基-1-萘醛与水合肼形成的席夫碱,[(HO)(C₁₀H₆)CH=N-N=CH(C₁₀H₆)(OH)],作为配体,设计组装了双核三螺旋的三价铁配合物。配合物中每一个铁离子以准八面体的配位方式分别与三个NO双齿单元配位, 三个配体分别桥联两个金属形成特定的三螺旋构型。分子内和分子间的π-π堆积作用对螺旋体的形成和堆积方式起着十分重要的作用。作为对照,本文还报道了配体的晶体结构。     

酰胺型配体铜、锌、银配合物的合成、结构及荧光性质

合成并通过单晶衍射表征了5个配合物[CuLCl₂]·CH₃COCH₃（1）、[ZnLCl₂]·CH₃COCH₃（2）、[ZnL（NO₃）₂]·0.5CH₃COCH₃（3）、[AgL₂]ClO₄（4）和[AgL₂]BF₄（5）（L=2-（5-氯-8-喹啉氧基）-1-（吡咯烷-1-基）乙酮）。配合物1和2同构,五配位的中心金属离子采取扭曲的四方锥配位构型,与来自配体L的2个氧原子和1个氮原子及2个氯离子配位。而在配合物3中,锌离子与1个三齿配位的配体L,1个单齿配位的硝酸根和1个双齿配位的硝酸根配位,配位构型为扭曲的八面体。配合物4和5中,中心金属与配体的比例为1∶2。银离子与2个三齿配位的配体L配位,采取扭曲的八面体配位构型。乙腈溶液中,配合物1、2、4和5在410 nm处的最大荧光发射峰与配体L相似。而配合物3由于配体到锌离子之间的能量转移,最大荧光发射峰红移至430 nm。     

二维配位聚合物[Cd(C4O4)(C12N2H8)(H2O)]n的合成、晶体结构与性能研究

本文采用邻菲罗啉和方酸为配体，在水热条件下通过自组装合成了具有二维网状结构的配位聚合物[Cd(C₄O₄)(C₁₂N₂H₈)(H₂O)]_n，并应用X-光衍射技术测定了其单晶结构。结果表明：Cd原子与2个邻菲罗啉氮原子、3个方酸氧和1个水分子配位，生成了六配位扭曲八面体。方酸以少见的μ-1，2，3配位模式桥联3个中心金属离子，并进一步组装成二维网状配位聚合物。对配位聚合物的光学性能及热稳定性做了进一步的研究，实验结果表明：配位聚合物是具有良好热稳定性的强荧光材料，具有潜在的应用前景。     

水溶性Pt(Ⅱ)-Salen配合物的合成、表征和光催化制氢研究

本文合成了一种水溶性的Pt(II)-Salen配合物(Salen=双5-磺酸钾水杨醛合邻苯二胺席夫碱),将其用于光催化制氢.研究发现在光催化制氢体系中仅存在Pt(II)-Salen配合物和三乙胺(TEA)而没有额外加入催化剂时,在可见光照射下有氢气产生.进一步的研究表明,Pt(II)-Salen配合物在体系中既是光敏剂,又是催化剂Pt纳米粒子的前体.同时,制氢体系中除了TEA外没有使用有机溶剂.该结果为简化多组分制氢体系提供了新思路.     

Homogeneous catalytic system for photoinduced hydrogen production utilizing iridium and rhodium complexes

An efficient homogeneous catalytic system for the visible-light-induced production of hydrogen from water utilizing cyclometalated iridium(III) and tris-2,2'-bipyridyl rhodium(III) complexes is described. Synthetic modification of the photosensitizer Ir(C--N) 2(N--N) (+) and water reduction catalyst Rh(N--N) 3 (3+) creates a family of catalysts with diverse photophysical and electrochemical properties. Parallel screening of the various catalyst combinations and photoreaction conditions allows the rapid development of an optimized photocatalytic system that achieves over 5000 turnovers with quantum yields ( (1)/ 2 H 2 per photon absorbed) greater than 34%. Photophysical and electrochemical characterization of the optimized system reveals that the reductive quenching pathway provides the necessary driving force for the formation of [Rh(N--N) 2] (0), the active catalytic species for the reduction of water to produce hydrogen. Tests for system poisoning with mercury or CS 2 provide strong evidence that the system is a true homogeneous system for photocatalytic hydrogen production.     

New pyridinium based ionic dyes for the hydrogen evolution reaction

The presented work comprised the synthesis and characterization of new ionic organic dyes as potential photosensitizer (PS) in the photocatalytic H₂ evolution reaction. The presented dyes are consisting of donor-π-acceptor (D-π-A) structures that are commonly used for organic dyes for organic solar cells. The acceptor is based on a cationic pyridinium moiety. Furthermore, a complex was synthesized, in which a D-π-A photosensitizer is linked as ligand to cobaloxime. The latter is a common proton reduction catalyst. The attached ligand enabled a fast intramolecular electron transfer to the cobalt center. The resulted complex showed high stability and potential in the homogeneous photocatalytic H₂ evolution reaction. Finally, one ionic dye showed a high activity when combined with TiO₂ and Pt in a heterogeneous hydrogen evolution reactions with a TOF of up to 407 h^?1.     

Hydrogen Production on a Hybrid Photocatalytic System Composed of Ultrathin CdS Nanosheets and a Molecular Nickel Complex

The production of clean and renewable hydrogen through water splitting by using solar energy has received much attention due to the increasing global energy demand. We report an economic and artificial photosynthetic system free of noble metals, consisting of ultrathin CdS nanosheets as a photosensitizer and nickel‐based complex as a molecular catalyst. Emission quenching and flash photolysis studies reveal that this hybrid system allows for effective electron transfer from the excited CdS nanosheets to the nickel‐based complex to generate reduced intermediate species for efficient hydrogen evolution. Notably, the unique morphological and structural features of the ultrathin CdS nanosheets contribute to the highly efficient photocatalytic performance. As a consequence, the resulting system shows exceptional activity and stability for photocatalytic hydrogen evolution in aqueous solution with a turnover number (TON) of about 28 000 versus catalyst and a lifetime of over 90 h under visible light irradiation.     

Electrochemical and photochemical hydrogen generation by a water soluble cobalt(II) complex of 2,2-bipyridine

A molecular catalyst based on a cobalt(II) complex, [(bpy)₂Co(SCN)(Cl)] 1, has been prepared by the reaction of 2,2-bipyridine (bpy), CoCl₂·6H₂O, and KSCN. The complex has been investigated for both electrocatalytic hydrogen generation and photocatalytic hydrogen generation from purely aqueous solution. Under photoirradiation with blue light (λ _max = 469 nm), with [Ru(bpy)₃]Cl₂ as a coupled photosensitizer and ascorbic acid (H₂A) as a sacrificial electron donor in pH 5.0 aqueous solution, complex 1 possesses good activity with an initial turnover rate of 2.7 × 10³ mol of H₂ per mole of catalyst for the first 3 h of photolysis. This activity can be sustained for at least 10 h with a turnover number of 1.2 × 10⁴ mol of H₂ per mole of catalyst. Additionally, complex 1 electrocatalyzes hydrogen generation from neutral water (pH 7.0) with a turnover frequency of 809 mol of hydrogen per mole of catalyst per hour at an overpotential of 837.6 mV.     

无氧条件下Pt/TiO2光催化重整降解一乙醇胺水溶液制氢

以一乙醇胺（以下简称乙醇胺）为电子给体,在无氧条件下进行了Pt/TiO2光催化重整制氢的研究.详细讨论了诸多因素如催化剂表面Pt化学状态、Pt担载量、溶液pH值、乙醇胺溶液浓度等对产氢效率的影响,并用XRD、HNMR、XPS等进行了深入表征,探讨了Pt/TiO2光催化重整降解乙醇胺和产氢的反应, 实验表明,利用所制备的光催化剂, 可实现在消除水中有机污染物的同时制取氢气的目标.催化剂表面的Pt以Pt0的化学状态存在, 有利于析氢;溶液pH值和浓度的变化对产生速率也有一定的影响.同时发现Pt/TiO2光催化重整乙醇胺制氢反应的最佳条件是:Pt的最佳担载量约为0.5％～1.0％;乙醇胺溶液最佳浓度约为0.05 mol•L－1;最佳溶液pH值范围为4～10;氨基取代的羰基类化合物是其主要中间产物.     

Cyclodextrin-based systems for photoinduced hydrogen evolution

Light-driven catalytic three component systems for the reduction of protons, consisting of a cyclodextrin-appended iridium complex as photosensitizer, a viologen-based electron relay, and cyclodextrin-modified platinum nanoparticles as the catalyst, were found to be capable of producing molecular hydrogen effectively in water, using a sacrificial electron donor. The modular approach introduced in this study allows the generation of several functional photo-active systems by self-assembly from a limited number of building blocks. We established that systems with polypyridine iridium complexes of general formula [Ir(ppy)(2)(pytl-R)]Cl (ppy, 2-phenylpyridine; pytl, 2-(1-substituted-1H-1,2,3-triazol-4-yl)pyridine) as photosensitizers are active in the production of H(2), with yields that under our experimental conditions are 20-35 times higher than those of the classical system with [Ru(bpy)(3)]Cl(2) (bpy, 2,2'-bipyridine), methyl viologen, and Pt. By investigating different photocatalytic systems, it was found that the amount of hydrogen produced was directly proportional to the emission quantum yield of the photosensitizer.     

利用静电吸引作用提高光催化放氢效率

本文设计合成了两个分别带正电荷和负电荷的Ir(Ⅲ)配合物[Ir(ppy)₂(bpy)]⁺(ppy=2-苯基吡啶,bpy=2,2′-联吡啶)和[Ir(ppy)₂(pbs)]^-(pbs=1,10-菲啰啉-4,7-二苯磺酸钠)作为光敏剂,以[Co(bpy)₃]²⁺为放氢催化剂,比较了Ir(Ⅲ)配合物的光催化放氢效率.发现带负电荷的Ir(Ⅲ)配合物具有更高的光催化放氢效率,带负电荷光敏剂和带正电荷催化剂间的静电吸引可能对放氢效率的提高起到了重要作用.     

方胺功能化荧光金属-有机框架材料的制备及对组氨酸的识别研究

以方胺功能化配体5,5′-[(3,4-二氧环丁-1-烯-1,2-二基)二(氮烷二基)]二间苯二甲酸(H₄L)和六水合硝酸钴为原料, 在碱性条件下通过水热反应制备了一种方胺功能化的金属-有机框架材料(Co-L). X射线单晶衍射结果显示, 该材料是由一维链通过CH…π和氢键相互作用形成的三维网络结构, 在b轴和c轴方向分别存在窗口直径为0.52和0.63 nm的一维孔道. 荧光测试结果表明, Co-L可在20种天然氨基酸中高选择性地检测组氨酸, 并对其检测机理进行了研究.