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1.
Ligands in coordination chemistry and homogeneous catalysis are traditionally “static” spectators that do not actively participate in the catalytic cycle. However, such classic systems do not provide additional “handles” that could facilitate or trigger alternative productive reaction pathways. Recent advances in the use of novel nitrogen‐centered pincer systems have unveiled interesting opportunities for cooperative catalysis. The chemistry of pyridine‐derived, neutral ligands is discussed, with a specific focus on their non‐innocent behavior and potential as facilitators for metal‐mediated organic transformations. This overview should provide inspiration and an incentive to incorporate non‐innocent ligands and their metal complexes within old and new homogeneously catalyzed reactions.  相似文献   

2.
自然界在漫长的进化过程中创造了大量具备优异特性的天然材料,为人工材料的设计和制备以及相关学科的发展提供了源源不断的灵感来源.得益于材料科学和微加工制造工艺的飞速发展,受自然界天然材料启发而构建的仿生材料受到科研界的广泛关注并随之蓬勃发展.基于精细的形貌加工和组分设计,仿生材料已经被赋予自适应、自修复、自清洁以及雾收集等...  相似文献   

3.
Dearomatized N-heterocycles are an important class of structural motifs for organic synthesis and chemical biology. The catalytic dearomative reduction of unactivated N-heteroarenes using silicon and/or boron-containing compounds as a reductant is one of the most straightforward alternatives to hydrogenation. However, thus far, there are few reported examples on the catalytic reduction of N-heteroaromatic compounds with silane or borane reducing agents. This Review presents recent advances in the catalytic reduction of unactivated N-heteroarenes by hydrosilanes, hydroboranes, silaboranes, and diboranes. The focus is on the chemical reactivity and selectivity of transition-metal or metal-free organocatalyst systems. In addition, the working modes of these catalysis will be described primarily on the basis of experimental mechanistic insight.  相似文献   

4.
Exploring bioelectroanalysis and bioelectrocatalysis in non-aqueous systems are essential for bridging the gap between laboratorial and industrial scale. Bioelectrodes based on carbon nanomaterials, such as carbon nanotubes and graphene, have been designed and fabricated with biocompatible surface functionalities. This review presents recent advances in regulation of a biocompatible microenvironment of enzyme electrodes in non-aqueous systems. We summarize the modification strategies to facilitate electron transfer and promote enrichment of hydrophobic analytes. We focus on the mining and modification for robust oxidoreductases from extremophiles to explore the biosensors in extreme conditions. Challenges and future prospects for bioelectrodes in non-aqueous systems are discussed.  相似文献   

5.
Sequence-defined polymers can be programmed to self-assemble into precise nanostructures for applications in biosensing, drug delivery, optics, and molecular computation. Inspired by the natural self-assembly processes present in biological protein and DNA systems, sets of molecular design rules have emerged across materials classes as instructions to build a variety of tunable structures. This review highlights recent advances in self-assembled sequence-defined and sequence-specific polymers across peptides, peptoids, DNA, and non-biological synthetic materials, with a focus on synthesis, assembly processes and overall structure. Specifically, these self-assembled structures are free-floating, as such constructs can potentially serve as a platform for the aforementioned applications. Emphasis is placed on the molecular design of polymers that self-assemble into zero-dimensional, one-dimensional, two-dimensional, or three-dimensional nanostructures. With the development of automated syntheses and increasing control over self-assembly, future work may focus on emerging classes of compatible hybrid materials with exciting directions toward new architectures and applications.  相似文献   

6.
The development of new materials based on hydroxyapatite has undergone a great evolution in recent decades due to technological advances and development of computational techniques. The focus of this review is the various attempts to improve new hydroxyapatite-based materials. First, we comment on the most used processing routes, highlighting their advantages and disadvantages. We will now focus on other routes, less common due to their specificity and/or recent development. We also include a block dedicated to the impact of computational techniques in the development of these new systems, including: QSAR, DFT, Finite Elements of Machine Learning. In the following part we focus on the most innovative applications of these materials, ranging from medicine to new disciplines such as catalysis, environment, filtration, or energy. The review concludes with an outlook for possible new research directions.  相似文献   

7.
8.
Diabetes mellitus (DM) is the most prevalent non‐contagious disease, which has affected a large number of people all over the world. Among all treatments known to have a positive influence in the control of DM, insulin therapy is the most common and effective one. Nowadays, various methods of insulin delivery are under investigation, which are able to reach a plausible bioavailability with ignorable side effects instead of insulin injection. This article presents a comprehensive review of the insulin therapy approach with a focus on modified methods in insulin delivery strategies and current advances in engineered insulin delivery systems.  相似文献   

9.
Mesoscopic aggregate is important to transfer or even amplify the molecular information in macroscopic materials. As an important branch of aggregate science, aggregation-induced emissive luminogens (AIEgens) often show slight or even no emission in solutions but exhibit bright emission when they aggregate, which open a new avenue for the practical applications. Due to the flexible and rotor structure of AIEgens, the aggregate structure of AIEgens is highly sensitive to the surrounding microenvironment, resulting in adjustable optical properties. Fibers integrated of a multiplicity of functional components are ideal carriers to control the aggregation processes, further assembly of fibers produces large-scale fabrics with amplified functions and practical values. In this Concept article, we focus on the latest advances on the synergy between “AIE+Fiber” for the boosted performance that beyond AIE, and their applications are presented and abstracted out to stimulate new ideas for developing “AIE+Fiber” systems.  相似文献   

10.
Unconventional detection methods for microfluidic devices   总被引:2,自引:0,他引:2  
The direction of modern analytical techniques is to push for lower detection limits, improved selectivity and sensitivity, faster analysis time, higher throughput, and more inexpensive analysis systems with ever-decreasing sample volumes. These very ambitious goals are exacerbated by the need to reduce the overall size of the device and the instrumentation - the quest for functional micrototal analysis systems epitomizes this. Microfluidic devices fabricated in glass, and more recently, in a variety of polymers, brings us a step closer to being able to achieve these stringent goals and to realize the economical fabrication of sophisticated instrumentation. However, this places a significant burden on the detection systems associated with microchip-based analysis systems. There is a need for a universal detector that can efficiently detect sample analytes in real time and with minimal sample manipulation steps, such as lengthy labeling protocols. This review highlights the advances in uncommon or less frequently used detection methods associated with microfluidic devices. As a result, the three most common methods - LIF, electrochemical, and mass spectrometric techniques - are omitted in order to focus on the more esoteric detection methods reported in the literature over the last 2 years.  相似文献   

11.
《Progress in Surface Science》2007,82(7-8):407-434
Recent advances in synthetic methods and analysis techniques provide a basis for the construction and characterization of organized arrays of molecular switches and motors on surfaces. Among them, molecular systems that can be controlled by light are particularly promising because of their ease of addressability, fast response times and the compatibility of light with a wide range of condensed phases. The aim of this contribution is to highlight selected recent advances in building functional monolayers of light-activated molecules. Special focus is given to monolayers of molecules whose collective switching properties have been harnessed to produce macroscopic effects. The design, structure, and function of monolayers composed of bistable photochromic switches, which can control chirality, wettability, conductivity and self-assembly are described. A recent report on the successful demonstration of light-driven rotary motors functioning while grafted on gold surfaces will also be discussed, followed by a brief conclusion.  相似文献   

12.
The volatile compounds present in wines are responsible for the quality of the wine aroma. The analysis of these compounds requires different analytical techniques depending on the type of compounds and their concentration. The importance at sensorial level of each compound should be evaluated by using olfactometric techniques and reconstitution and omission studies. In addition, wine aroma is influenced by other factors such as wine matrix, which could affect the compounds’ volatility, decreasing or increasing their concentration in the headspace above the wine. Moreover, when a wine is consumed, several oral physiological variables could affect aroma perception. The focus of this review is to outline the most recent advances in wine aroma analysis and the most innovative techniques in trying to elucidate the main factors that influence wine aroma perception during consumption.  相似文献   

13.
The present review presents the state of the art of the developments, key strategies and analytical applications of chemiluminescence detection coupled to CE (CE‐CL). Different parts considering the most common CL systems have been included, such as the tris(2,2′‐bipyridine)ruthenium(II) system, the luminol and derivatives reaction, the peroxyoxalate CL or direct oxidations. New advances in homemade configurations and applications in different fields such as clinical, pharmaceutical, environmental and food analysis have been included. The focus is on studies which appeared from 2000 to the end of 2009.  相似文献   

14.
Self-assembled polymeric systems have played an important role as templates for nanofabrication; they offer nanotemplates with different morphologies and tunable sizes, are easily removed after reactions, and could be further modified with different functional groups to enhance the interactions. Among the various self-assembled polymeric systems, block copolymer supramolecular assemblies have received considerable attention because of the inherent processing advantages. These supramolecular assemblies are formed by the non-covalent interactions of one of the blocks of the block copolymer with a low molar-mass additive. Selective extraction of the additive leads to porous membranes or nano-objects which could then be used as templates for nanofabrication leading to a variety of ordered organic/inorganic nanostructures. In this feature article, we present an over-view of the recent developments in this area with a special focus on some examples from our group.  相似文献   

15.
The past decade has seen growing interest in the investigation of self-assembling nanostructures, particularly in aqueous solution. In this context, polypeptide-based copolymers show considerable promise as building blocks that allow enhanced control over intra- and intermolecular interactions, in concert with stable, yet modifiable, secondary and tertiary structures. We will focus here on the most recent advances in the formation of micelles and vesicles from peptide–polymer conjugates or from copolypeptide systems, and on the capacity of these structures to manifest stimuli-driven variation in size and shape. We will also discuss a new generation of materials based on protein-like copolymers that offer precise control over molecular composition and structure along with predetermined biological functionality.  相似文献   

16.
Research for materials offering efficient hydrogen storage and transport has recently received increased attention. Metal organic frameworks (MOFs) provide one promising group of materials where several recent advances were reported in this direction. In this computational study ab initio methods are employed to study the physisorption of hydrogen on conjugated systems. These systems are used as models for the organic linker within MOFs. Here, we focus on the adsorption sites related to the organic linker with special attention to the edge site, which was only recently reported to exist as the weakest adsorbing site in MOFs. We also investigate chemically modified models of the organic connector that result in enforcing this adsorption site. This may be crucial for improving the uptake properties of these materials to the goal defined by DOE for efficient hydrogen transport materials.  相似文献   

17.
18.
Mechanochromic organic materials are a typical class of stimuli materials that has response to external physical stimuli such as shearing, grinding, and compressing etc. Organic compounds with mechanochromic characters in solid forms have attracted significant attention in the past decades due to their potential applications in sensors and memory devices. Diamond anvil cell is an emerging technology that can provide isotropic pressure in a tiny place. Thus a new stimuli method can be applied in investigating optical variation of mechanochromic materials. In this review, we focus on mechanoluminescence systems that are responsive to isotropic compression under high pressure and summarize the recent advances on organic materials studied by the diamond anvil cell.  相似文献   

19.
Platinum group metal (PGM) nanoparticles (NPs) have been investigated in a variety of research fields such as catalysis and electronics. Alloying has been recognized as one of the most efficient ways of improving or creating properties in metals. Among the types of alloys, solid-solution alloy NPs have the advantage of being capable of continuously changing their properties by tuning their composition. However, synthesizing PGM solid-solution alloy NPs with any combination and composition is not an easy task owing to the metallurgical aspects. In this minireview, the focus is on recent advances in PGM-based solid-solution alloy NPs, and in particular those with immiscible alloy systems. Concepts, synthesis, and properties of the alloy NPs are introduced, and the existing challenges and future perspectives are discussed.  相似文献   

20.
Droplet microfluidics for the study of artificial cells   总被引:1,自引:0,他引:1  
In this review, we describe recent advances in droplet-based microfluidics technology that can be applied in studies of artificial cells. Artificial cells are simplified models of living cells and provide valuable model platforms designed to reveal the functions of biological systems. The study of artificial cells is promoted by microfluidics technologies, which provide control over tiny volumes of solutions during quantitative chemical experiments and other manipulations. Here, we focus on current and future trends in droplet microfluidics and their applications in studies of artificial cells.  相似文献   

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