可见光铋系光催化剂的研究进展

当前工业发展导致了严重的能源和环境危机,光催化为这一难题提供了有效的解决方案.然而在实际应用中,传统氧化物光催化剂宽的带隙限制了它的可见光吸收,于是窄带隙光催化剂成为了研究的热点.其中铋系光催化剂以其高的可见光光催化活性引起了人们的广泛关注.因此本文介绍了铋系光催化剂的种类、制备、形貌、复合、性能等方面的研究现状,并展望了含铋可见光催化剂发展前景.     

铋基金属有机框架的合成与应用

金属有机框架(MOFs)材料因其丰富的拓扑结构和有序的孔洞结构被广泛关注,近年来人们按照其不同的应用前景分别进行了综述。尽管金属中心与有机框架材料的结构及性能有着密切联系,目前针对某种特定中心金属的金属有机框架材料的梳理还较少。金属铋是唯一一种具有较大丰度、低毒性的绿色重金属元素,铋基金属有机框架(Bi-MOFs)也因此在MOFs中脱颖而出,并具有广泛的应用。由于铋盐易水解的特性,在水相中合成铋基金属有机框架材料一直是一个挑战,所以对于Bi-MOFs的开发仍然处于开始阶段。本文介绍了近年来有关Bi-MOFs常用的合成配体以及一般的合成方法,综述了Bi-MOFs在光、电催化等领域的研究进展及其在药物载体、气体吸附剂及电极材料方面的应用概况。对存在的问题进行总结并提出可能的解决方法,对未来研究和应用提出展望,以推动Bi-MOFs材料的进一步研究与运用。     

有机小分子电致发光研究进展

有机电致发光具有发光亮度和发光效率高,材料易加工等传统的无机和液晶显示材料无可比拟的优点,并且可以通过改变分子结构或掺杂调谐发光的颜色.本文评述了近年来有机小分子电致发光材料的研究进展,简要介绍了有机电致发光的原理及其广阔的应用前景.     

有机钛氢化物的化学

本文综述了有机钛氢化物化学的最近进展,包括:合成方法,反应及其在有机合成中的应用。     

用于烯烃化学的新型有机铼催化剂

德国慕尼黑工业技术大学Herrmann教授最近发展了以甲基三氧化铼(Ⅶ)作为均相或异相催化剂广泛应用于烯烃复分解、烯烃氧化和醛转化为烯烃等几个过程。这些过程可用于制备某些商品重要的树脂如聚链烯(polyalkenomer)以及官能团烯烃、桥氧化物、二醇等精细化学品甲基三氧化鳞(MTO,CH_3ReO_3)是最     

钯或镍催化的有机镁及有机锌的不对称交叉偶联反应

综述了钯或镍的手性配合物催化的有机金属试剂与芳基及烯基卤化物的不对称交叉偶联反应,着重介绍了手性配体的发展及其对反应产物ee值的影响。对一些已研究得较清楚的反应的可能立体识别机理也作了介绍。     

铋系光催化剂的形貌调控与表面改性研究进展

铋系光催化剂是一类重要的可见光光催化剂,但块体铋系化合物的光催化性能并不理想,需进行改性增强。形貌调控和表面改性是增强铋系光催化剂性能的两种有效方法。本文对近年来铋系化合物光催化剂形貌调控和表面改性方面的研究报道进行综述总结,介绍通过超薄纳米片制备、晶面比例调控、分级结构和空心结构构筑、官能团和纳米微粒修饰表面、表面缺陷调控以及表面原位转化形成金属铋和含铋化合物纳米颗粒等方法增强铋系光催化剂性能的研究情况,对各种方法的特点及其在增加光吸收、有效分离和利用光生载流子方面的作用机制进行讨论,并对铋系光催化材料的形貌调控与表面改性的未来发展趋势及所面临的挑战进行分析总结。     

有机荧光材料研究进展

对三类主要的有机荧光材料－－具刚性结构的芳香稠环化合物，具共轭结构的分子内电荷转移化合物及某些金属配合物尤其是稀土金属配合物近二十年来的研究与应用进行了综述，引用文献48篇。     

有机小分子催化合成高聚物的研究进展

综述了有机小分子催化剂在高分子合成上应用的研究进展,着重分析催化剂结构与催化效能、单体的选择性以及聚合物的性质之间的关系。     

铋、铈钼酸盐催化剂的丙烯选择氧化动力学研究

本文目的在于研究稀土对钼酸铋的丙烯选择氧化影响,不同比例的催化剂呈现了比较复杂的动力学行为,随着催化剂组成变化,氧反应级数可由零级经过0.5级直至无一定反应级数,对丙烯的反应级数也随组成改变有很大变化,为解释这一现象,本文提出了统一反应机理,即随着催化剂组成变化,催化剂表面活性中心由晶格氧经历吸附原子态氧至吸附分子态氧变化,通过X光、红外及其它实验结果表明,预期这样的活性中心变化是由于铈的存在形成了钼酸铈晶相,破坏了钼酸铋晶体形成而促使钼酸铋更加分散缘故。     

Synthesis and catalytic application of Pd complex catalysts: Atom‐efficient cross‐coupling of triarylbismuthines with haloarenes and acid chlorides under mild conditions

Palladium‐catalysed cross‐coupling reactions are some of the most frequently used synthetic tools for the construction of new carbon–carbon bonds in organic synthesis. In the work presented, Pd(II) complex catalysts were synthesized from palladium chloride and nitrogen donor ligands as the precursors. Infrared and ¹H NMR spectroscopic analyses showed that the palladium complexes were formed in the bidentate mode to the palladium centre. The resultant Pd(II) complexes were tested as catalysts for the coupling of organobismuth(III) compounds with aryl and acid halides leading to excellent yields with high turnover frequency values. The catalysts were stable under the reaction conditions and no degradation was noticed even at 150°C for one of the catalysts. The reaction proceeds via an aryl palladium complex formed by transmetallation reaction between catalyst and Ar₃Bi. The whole synthetic transformation has high atom economy as all three aryl groups attached to bismuth are efficiently transferred to the electrophilic partner.     

Nickel‐Catalyzed Amination of Aryl Chlorides with Ammonia or Ammonium Salts

The nickel‐catalyzed amination of aryl chlorides to form primary arylamines occurs with ammonia or ammonium sulfate and a well‐defined single‐component nickel(0) precatalyst containing a Josiphos ligand and an η²‐bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts.     

Pd‐Catalyzed Synthesis of α‐Aryl Vinylphosphonates via Suzuki Arylation of α‐Phosphonovinyl Nonaflates

The first palladium‐catalyzed method for the arylation of α‐phosphonovinyl nonaflates is described. Using a catalyst comprised of Pd(OAc)₂ and SPhos, terminal and internal α‐aryl vinylphosphonates could be efficiently accessed under mild conditions. The reaction features a broad coupling partner scope and tolerates many functional groups.     

Peripheral Arylation of Subporphyrazines

Peripherally hexaarylated subporphyrazines (SubPzs) have been prepared through a Pd‐catalyzed, CuTC‐mediated coupling of a hexaethylsulfanylated subporphyrazine with arylboronic acids. The introduced aryl substituents strongly influence the electronic properties of the subporphyrazine through effective conjugative interaction. Aryl rings endowed with π‐electron‐donating groups at the para positions produce a remarkable perturbation of the electron density of the SubPz macrocycle. This is reflected through significant redshifts of the SubPz CT and Q‐bands, together with increase of the molar absorptivity of the former, with respect to those exhibited by the hexaphenyl‐SubPz 2 a . Moreover, the trend in the first SubPz reduction potentials correlates with the Hammett constants (σ_p) corresponding to the para substituents of the aryl. The domed, extended SubPz π‐system self‐assembles in the solid state to form a dimeric capsule that houses a solvent molecule.     

Catalytic C?C,C?N,and C?O Ullmann‐Type Coupling Reactions

Copper‐catalyzed Ullmann condensations are key reactions for the formation of carbon–heteroatom and carbon–carbon bonds in organic synthesis. These reactions can lead to structural moieties that are prevalent in building blocks of active molecules in the life sciences and in many material precursors. An increasing number of publications have appeared concerning Ullmann‐type intermolecular reactions for the coupling of aryl and vinyl halides with N, O, and C nucleophiles, and this Minireview highlights recent and major developments in this topic since 2004.