探求纳米科技新路径——记南京工业大学先进化学制造研究院执行院长陈虹宇

相较于大多数人运用已知的纳米结构去拓展应用,陈虹宇眼下的工作则是在扩充纳米合成能力的"工具箱",进一步推动纳米研究向复杂结构的发展。他是世界上少数几个"为了纳米合成而合成"的人,本着化繁为简、阐明原理机制的原则,致力探索纳米领域合成方法学的新篇章。     

铁酸锌纳米晶的制备及其防辐射性能的分析

研究纳米铁酸锌合成及防辐射性能;防辐射性能是现代防辐射材料发展历程中标准的重要衡量方法;传统的防辐射方法多采用化学共沉淀法和微乳液法单分子前驱体法,合成效果差,导致材料的防辐射性能不达标;提出一种纳米铁酸锌合成及防辐射性能评判方法,采用共沉淀法和溶溶剂热法相结合制备铁酸锌纳米晶体,合成后,利用红外光谱仪(FT-IR)、X射线衍射(XRD)、透射电子显微镜(TEM)和扫描电子显微镜对纳米级Zn Fe2O4晶体的晶体结构和形貌进行了研究,最后,将材料合成到纺织物上,测试材料的防辐射性能,结果显示,采用基于纳米铁酸锌合成的防辐射材料,防辐射性能远远优于传统合成方法合成的材料,具有非常广泛的防辐射应用价值。     

表面活性剂在纳米材料合成与制备中的应用

本文主要介绍了近几年表面活性荆在合成与制备纳米粉体材料、纳米复合材料、纳米结构材料中的应用.     

新型含氮、硫、氧配体及其超分子化合物的设计合成

以结构化学指导新型金属 有机纳米器件的合理合成和物理性能研究,探索它们的自组装规律,共设计合成了 1 2个含N、S及COO- 基团的具有不同对称性和立体选择性的新颖大骨架多官能团柔性配体,以及由它们与金属离子自组装合成了 1 8个新型金属 有机纳米笼、纳米管和配位聚合物,开辟了一条合成金属 有机纳米器件的新途经。其中,一个具有Oh对称的金属纳米笼,笼内体积超过 1 0 0 0 A3,可以同时容纳多种离子和小分子,是目前已测定单晶结构的金属纳米笼中容量最大的一个。而用金属离子把纳米管串联成的金属 有机纳米管则是国际上首例报道的结构有序无机 有机纳米管阵列;并创新性的采用低温溶剂热法合成了一个新颖的具有半导体和顺磁性质的Ni 巯基嘧啶二维层状聚合物和两个二维折叠格子状化合物;另外,用巯基嘧啶作为难溶盐CuCN的溶解模板,得到了国际上首例六角形CuCN大环化合物和另外一个新颖的类石墨层状CuCN化合物.　　过渡金属与多官能团配体通过配位键来驱动和引导自组装,形成具有均一尺寸和特定形状的金属 有机纳米器件,是当今化学与材料领域研究的前沿之一。而通过设计合成具有特定对称性和立体选择性的有机配体,并把它们与金属离子自组装形成具有纳米尺寸和特殊功能的纳米球和纳米管,更是在纳米科技、     

微结构决定的具有均一米状形貌的新奇银纳米颗粒的高产率合成

物理所／北京凝聚态物理国家实验室徐红星研究组的梁红艳同学和王文忠教授首次用多羟基醇还原法合成了一种外形为纺锤状的银纳米颗粒（Ag Nanorice）,并与李建奇研究组的杨槐馨副研究员合作,发现这种银纳米颗粒为六方相和立方相交生形成,内部存在孪晶,堆垛层错,多重调制等多种缺陷结构,并且缺陷密度在银纳米颗粒的不同部位有着明显区别,这种微结构突破了传统银纳米颗粒常规的单晶、孪晶特性,决定了具有均1米状形貌的新奇银纳米颗粒的高产率合成。该项研究的意义不仅为有效调制表面等离子体共振特性提供了新的纳米结构,而且这种堆垛结构可能打破晶体生长时晶体结构对形貌的限制．为设计合成所需形貌晶体带来曙光。     

ZnO光阳极在染料敏化太阳能电池中的形貌研究进展

介绍了应用于染料敏化太阳能电池(DSSC)中不同形貌Zn O光阳极,讨论了不同方法合成的Zn O纳米粒子、纳米片、纳米线、纳米棒、纳米管、纳米纤维、纳米带、纳米花等光阳极形貌对DSSC光伏性能的影响,并展望了Zn O光阳极今后研究趋势。     

纳米金刚石提纯技术研究进展

爆轰法合成的纳米金刚石中含有大量的无定型碳、纳米石墨颗粒、金属、金属氧化物及其他外来元素。纳米金刚石规模化生产时,需选择性的去除产品中的非金刚石碳及其他杂质。本文概述了目前纳米金刚石的常用提纯技术,并对该技术的发展方向进行了探讨。     

一维纳米材料的光电性能研究

纳米技术是20世纪80年代中期诞生并正在不断崛起的新兴科学技术,近年来纳米线、纳米棒、纳米带、纳米管等一维纳米结构成为研究的焦点.本文在对一维纳束材料种类和合成的研究的基础上,对其光电性能做出了一定的分析.     

过渡金属原子簇化学研究

本文介绍了国家自然科学基金重大项目“过渡金属原子簇化学研究”的意义、背景、研究内容和研究进展以及今后的设想。其中研究进展主要是:系统地研究了若干系列簇合物的反应规律,使“活性元件组装”由设想发展为合成方法,在国际上率先提出了[Mo_3S_3]~(6+)簇环体系中存在的类芳香性概念:在国际上首次合成及表征了数百种过渡金属同核及异核新簇合物(例如含钼、钨、铁、铜、钴、镍、钒及稀土等系列的新型簇合物),对钴、铒和铁羰基簇合物二元复合体系的双金属协同效应及稀土-过渡金属簇合物的新体系等的研究。     

钼、铁、硫等原子簇化合物的合成化学与结构化学

中科科学院福建物质结构研究所卢嘉锡教授及其研究集体完成的“钼、铁、硫等原子簇化合物的合成化学与结构化学”研究项目,获得了第六次(1993)国家自然科学奖二等奖。卢嘉锡及其研究集体对过渡金属原子簇化合物,尤其是钼硫、铁硫、钼铁硫等簇合物进行了大量系统深入的研究工作,合成出类立方烷、双类立方烷、线型和三角形等多种结构类型的过渡金属簇合物200多个。通过X射线衍射等手段进行结构表征,总结出若干类型簇合物的化学特征,并采用多种谱学实验手段研究其物理化学性能,同时选择某些有典型意义的簇合物对其化学性能进行系统的研究。     

论产业集群的创新优势

本文认为，产业集群是规模变小的国家创新体系。在经济全球化背景下，产业集群不仅没有被套球化的浪潮淹没，反而不断涌现和发展壮大，关键在于产业集群拥有的创新优势。产业集群的创新优势表现为相互作用的行为主体间优越的学习能力。产业集群创新优势的实现主要通过地方环境的孵化作用、知识技能的扩散集聚作用以及跨国公司的催生作用等。在此基础上，提出产业集群创新优势培育的政策建议。     

Technological agglomeration and the emergence of clusters and networks in nanotechnology

Research and development at the nanoscale requires a large degree of integration, from convergence of research disciplines in new fields of enquiry to new linkages between start-ups, regional actors and research facilities. Based on the analysis of two clusters in nanotechnologies (MESA+ (Twente) and other centres in The Netherlands and Minatec in Grenoble in France), the paper discusses the phenomenon of technological agglomeration: co-located scientific and technological fields associated to coordinated technology platforms to some extent actively shaped by institutional entrepreneurs. Such co-location and coordination are probably a pre-requisite for the emergence of strong nanoclusters.     

硒催化羰基化反应若干进展

采用廉价的催化剂代替昂贵的金属,低成本的一氧化碳代替氢气乃至光气,一直是人们追求的目标.综述了非金属硒在含碳、氮、氧、硫类有机化合物中的催化羰基化反应,以及在Se/CO/H2 O体系中一些有机化合物的高选择性还原反应,介绍了近期的一些新进展.催化剂量的硒在温和条件下,即可活化一氧化碳而直接进行羰基化和还原反应,特别是发展了将硝基化合物的还原羰基化与胺的氧化羰基化相结合,合成一系列精细化学品和生物化学品.催化剂硒在催化反应中表现出反应过程相转移的特性,兼具了多相催化与均相催化的优点,是反应过程相转移概念中的典型实例.硒催化反应的特点是反应物转化率高,反应选择性专一,原子经济性高,对环境友好,且可部分替代光气合成法     

Unleash electron transfer in C–H functionalization by mesoporous carbon-supported palladium interstitial catalysts

The functionalization of otherwise unreactive C–H bonds adds a new dimension to synthetic chemistry, yielding useful molecules for a range of applications. Arylation has emerged as an increasingly viable strategy for functionalization of heteroarenes which constitute an important class of structural moieties for organic materials. However, direct bisarylation of heteroarenes to enable aryl-heteroaryl-aryl bond formation remains a formidable challenge, due to the strong coordination between heteroatom of N or S and transitional metals. Here we report Pd interstitial nanocatalysts supported on ordered mesoporous carbon as catalysts for a direct and highly efficient bisarylation method for five-membered heteroarenes that allows for green and mild reaction conditions. Notably, in the absence of any base, ligands and phase transfer agents, high activity (turn-over frequency, TOF, up to 107 h⁻¹) and selectivity (>99%) for the 2,5-bisarylation of five-membered heteroarenes are achieved in water. A combination of characterization reveals that the remarkable catalytic reactivity here is attributable to the parallel adsorption of heteroarene over Pd clusters, which breaks the barrier to electron transfer in traditional homogenous catalysis and creates dual electrophilic sites for aryl radicals and adsorbate at C2 and C5 positions. The d-band filling at Pd sites shows a linear relationship with activation entropy and catalytic activity. The ordered mesopores facilitate the absence of a mass transfer effect. These findings suggest alternative synthesis pathways for the design, synthesis and understanding of a large number of organic chemicals by ordered mesoporous carbon supported palladium catalysts.     

完全有序的全同金属纳米点阵列的生长与研究

利用“幻数稳定团簇 模板”方法在半导体Si(111)衬底上第一次成功地外延生长出了尺寸相同、空间分布均匀的金属纳米团簇阵列。这种方法适用于不同的金属,制备出的纳米团簇阵列热稳定性非常高。用扫描隧道显微镜(STM)原位分析结合第一性原理计算确定了纳米团簇的原子结构以及阵列的形成机理。     

Altering the rate-determining step over cobalt single clusters leading to highly efficient ammonia synthesis

Activation of high-energy triple-bonds of N₂ is the most significant bottleneck of ammonia synthesis under ambient conditions. Here, by importing cobalt single clusters as strong electron-donating promoter into the catalyst, the rate-determining step of ammonia synthesis is altered to the subsequent proton addition so that the barrier of N₂ dissociation can be successfully overcome. As revealed by density functional theory calculations, the N₂ dissociation becomes exothermic over the cobalt single cluster upon the strong electron backdonation from metal to the N₂ antibonding orbitals. The energy barrier of the positively shifted rate-determining step is also greatly reduced. At the same time, advanced sampling molecular dynamics simulations indicate a barrier-less process of the N₂ approaching the active sites that greatly facilitates the mass transfer. With suitable thermodynamic and dynamic property, a high ammonia yield rate of 76.2 μg h^–1 mg and superior Faradaic efficiency of 52.9% were simultaneously achieved.     

CMC聚合物对重金属离子的吸附性能

通过正交试验得出制备羧甲基纤维素(CMC)聚合物的最佳工艺条件:丙烯酸(AA)/羧甲基纤维素=10,引发剂(硫酸铵)和交联剂(N,N'-亚甲基双丙烯酰胺)用量分别为单体的0.0014倍和0.0015倍.吸胀平衡后,将CMC聚合物在400~450℃下完全灰化16h,消解并用火焰原子吸收法测定聚合物对Zn2+、Cu2+、Pb2+、Cd2+、Cr2+、Ni2+和Mn2+的吸附性能.结果表明,CMC聚合物对重金属离子具有一定的吸附能力,其吸附量随着溶液pH值和重金属离子质量浓度的增加而增大,当pH为9时达到最大;并且CMC聚合物对Pb2+和Cu2+的吸附量要大于其他金属离子.     

Hierarchically porous metal–organic frameworks: synthetic strategies and applications

Despite numerous advantages, applications of conventional microporous metal–organic frameworks (MOFs) are hampered by their limited pore sizes, such as in heterogeneous catalysis and guest delivery, which usually involve large molecules. Construction of hierarchically porous MOFs (HP-MOFs) is vital to achieve the controllable augmentation of MOF pore size to mesopores or even macropores, which can enhance the diffusion kinetics of guests and improve the storage capacity. This review article focuses on recent advances in the methodology of HP-MOF synthesis, covering preparation of HP-MOFs with intrinsic hierarchical pores, and modulated, templated and template-free synthetic strategies for HP-MOFs. The key factors which affect the formation of HP-MOF architectures are summarized and discussed, followed by a brief review of their applications in heterogeneous catalysis and guest encapsulation. Overall, this review presents a roadmap that will guide the future design and development of HP-MOF materials with molecular precision and mesoscopic complexity.     

手性1-[3,5-双(三氟甲基)苯基]乙醇的合成与拆分

3,5-双三氟甲基苯乙醇是一种重要的手性药物阿瑞吡坦的中间体,目前有多种制备方法.本文综述了手性1-[3,5-双(三氟甲基)苯基]乙醇合成与拆分的研究进展.从化学法和生物法两方面重点介绍了不对称合成制备光学活性1-[3,5-双(三氟甲基)苯基]乙醇的研究现状,概述了外消旋体1-[3,5-双(三氟甲基)苯基]乙醇拆分的方...     

The 2005 Bower Award in science presented to Henri B. Kagan

The scientific theme for the 2005 Bower Award was Chemistry, specifically the field of Catalysis. The Franklin Institute, Philadelphia, Pennsylvania, awarded the 2005 Bower Award and Prize for achievement in Science to Henri B. Kagan for his seminal discovery of fundamental chemical principles that explain the impact of catalyst shape on its effectiveness in controlling chemical reactions, thus greatly simplifying the manufacture of pharmaceutically important compounds. Henri Kagan is widely recognized as a pioneer in the field of asymmetric catalysis. Starting in the early 1970s, his reports of the synthesis of the chiral bidentate diphosphine ligand and the demonstration of its use with soluble rhodium compounds to catalyze the efficient production of large enantiomeric excesses of chiral molecules in asymmetric hydrogenations has had far reaching effects on research in the field asymmetric catalysis. The concept of using chiral bidentate ligands of C2 symmetry has led the way for numerous developments in asymmetric catalysis. Later in 1986 his introduction of the concept and investigations into “nonlinear effects in asymmetric synthesis” using catalysts with chiral ligands that were not optically pure challenged the widely accepted assumption that the enantiomeric excess which is possible correlates linearly with the optical purity of the chiral ligands. He reported the first example in asymmetric catalysis where the optical purity of the product significantly exceeded the optical purity of the chiral ligand.