Porphyrin complexes of the period 6 main group and late transition metals

Metalloporphyrin complexes of the period six metals gold, mercury, thallium, lead and bismuth are often overlooked in favour of their lighter congeners. These complexes exhibit unusual coordination geometries, prominently featuring the metal centre residing out the porphyrin plane. Not only are these compounds chemically interesting, but several applications for these complexes are beginning to emerge. Gold and bismuth porphyrins have medicinal applications including novel chemotherapeutics and sensitizers for α-radiotherapy, while gold porphyrins have applications in materials chemistry and catalysis. This perspective serves to highlight trends in the synthesis and structure of these heavy metal complexes as well as illustrate the considerations necessary for rationally designing elaborate porphyrin architectures.     

DNA modified with metal complexes: Applications in the construction of higher order metal–DNA nanostructures

DNA has recently emerged as a useful building block for higher order nanostructures, such as extended two-dimensional surfaces and discrete two- and three-dimensional structures. Transition metal complexes can introduce functionality to these otherwise passive nanostructures. This review examines the synthetic strategies used to introduce metals in a site-specific manner to DNA: either by attaching preformed metal complexes to DNA, or by metal coordination to unmodified or modified DNA. The applications of metal–DNA complexes in building higher order nanostructures and the utility of attaching luminescent or electrochemical labels are discussed.     

Nucleobase-containing transition metal complexes as building blocks for biological markers and supramolecular structures

The incorporation of metal complexes into nucleobases, nucleosides and nucleotides has provided a focus for the development of many novel compounds with a wide range of applications. In this perspective article the different methods to incorporate transition metal complexes into these species will be described. Applications of these compounds as biological markers, catalysts and how the hydrogen bonding properties may be employed in directing supramolecular assembly in both the solid state and solution will be discussed.     

Bioactive Luminescent Transition‐Metal Complexes for Biomedical Applications

The serendipitous discovery of the anticancer drug cisplatin cemented medicinal inorganic chemistry as an independent discipline in the 1960s. Luminescent metal complexes have subsequently been widely applied for sensing, bio‐imaging, and in organic light‐emitting diode applications. Transition‐metal complexes possess a variety of advantages that make them suitable as therapeutics and as luminescent probes for biomolecules. It is thus highly desirable to develop new luminescent metal complexes that either interact with DNA through different binding modes or target alternative cellular machinery such as proteins as well as to provide a more effective means of monitoring disease progression. In this Review, we highlight recent examples of biologically active luminescent metal complexes that can target and probe a specific biomolecule, and offer insights into the future potential of these compounds for the investigation and treatment of human diseases.     

Applications of luminescent inorganic and organometallic transition metal complexes as biomolecular and cellular probes

The rich photophysical properties of luminescent inorganic and organometallic transition metal complexes, such as their intense, long-lived, and environment-sensitive emission, render them excellent candidates for biological and cellular studies. In this Perspective, we review examples of biological probes derived from luminescent transition metal complexes with a d(6), d(8), or d(10) metal center. The design of luminescent covalent labels and noncovalent probes for protein molecules is discussed. Additionally, the recent applications of these complexes as cellular probes and bioimaging reagents are described. Emphasis is put on the structural features, photophysical behavior, biomolecular interactions, cellular uptake, and intracellular localization properties of luminescent transition metal complexes.     

Solid-state electroluminescent devices based on transition metal complexes

Transition metal complexes have emerged as promising candidates for applications in solid-state electroluminescent devices. These materials serve as multifunctional chromophores, into which electrons and holes can be injected, migrate and recombine to produce light emission. Their device characteristics are dominated by the presence of mobile ions that redistribute under an applied field and assist charge injection. As a result, an efficiency of 10 lm/W--among the highest efficiencies reported in a single layer electroluminescent device--was recently demonstrated. In this article we review the history of electroluminescence in transition metal complexes and discuss the issues that need to be addressed for these materials to succeed in display and lighting applications.     

含硅金属化合物的研究进展

近年来,含硅金属化合物由于在催化工业等领域的广泛应用受到了化学工作者的重视。本文综述了以硅原子或硅杂链为配体的桥形成的金属络合物、金属硅氧烷、硅-金属化合物、金属不饱和硅化物、含硅多金属络合物五种含硅金属化合物的研究进展。最后,并对该领域的研究方向提出了展望。     

Advances in the coordination chemistry of nitrogen ligand complexes of coinage metals

Coinage metals nitrogen chemistry has not been studied extensively until recently. The focus of this review is the base- and halide-free complexes of the monoanionic nitrogen ligands. This review describes how minor ligand modifications can result in a drastic change in the metal–metal interactions in multinuclear compounds. Crystal structures of these complexes show individual complexes, dimers, supramolecular columnar packing or more complex supramolecular aggregates. Bulky substituents on the ligands can prevent intermolecular metal–metal interactions or the formation of supramolecular architectures. The nuclearity and metal–metal interactions in these complexes are controlled by ligand steric and electronic factors and solvent of crystallization. Many classes of nitrogen ligand coordination compounds have given rise to advances in several fundamental and applied research aspects. Recent potential applications of nitrogen ligand complexes are highlighted particularly for those complexes included in this review.     

Decontamination of heavy metal complexes by advanced oxidation processes: A review

Heavy metal complexes with high mobility are widely distributed in wastewater from modern industries, which are more stable and refractory than free heavy metal ions. Their removals from wastewater draw increasing attentions and various technologies have been developed, among which advanced oxidation processes (AOPs) are more effectively and promising. Progresses on five representative types of AOPs, including Fenton (like) oxidation, electrochemical oxidation, photocatalytic oxidation, ozonation and discharge plasma oxidation for heavy metal complexes degradation are summarized in this review. Their rationales, advantages, applications, challenges and prospects are introduced independently. Combinations among these AOPs, such as electrochemical Fenton oxidation and photoelectrocatalytic oxidation, are also comprehensively highlighted. Future efforts should be made to reduce acid requirement and scale up for practical applications of AOPs for heavy metal complex degradation efficiently and cost-effectively.     

Metal centered ligand field excited states: Their roles in the design and performance of transition metal based photochemical molecular devices

Transition metal complexes are vital components in a wide range of photooptical applications; these range from targeted drug delivery to devices for the conversion of solar energy to electrical and/or stored chemical energy. Metal centered (MC) ligand field excited states play important roles in the photophysics of those complexes having partially filled d-orbitals. This review offers a broad perspective on key investigations that have characterized the chemistry and physics of MC excited states in d³ and d⁶ transition metal complexes. It will also illustrate the impact of these excited states on various photooptical applications and highlight efforts to understand, control, and tune these MC excited states in the context of such applications.     

Recent Mechanistic and Synthetic Developments in the Chemistry of Transition‐Metal Vinylidene Complexes

Transition‐metal vinylidene complexes are intermediates in a number of synthetically important transformations of alkynes. Underpinning these applications is the ability of various electron‐rich transition‐metal complexes to effectively facilitate the conversion of alkynes into their vinylidene tautomers. Recent experimental and theoretical studies have provided considerable insight into the mechanisms by which this process occurs and they are detailed herein. In particular, it has been demonstrated that different substituents on both the metal and the alkyne may have profound effects on both the kinetic and thermodynamic profiles of the alkyne/vinylidene tautomerisation. An important finding is that internal alkynes may be employed to prepare disubstituted vinylidene complexes under easily accessible conditions. This discovery brings to light a new facet of the potential synthetic applications of transition metal vinylidene complexes.     

Analytical applications of Raman spectroscopy

In this article interaction of transition metal complexes with DNA and its applications in electrochemical DNA biosensors as hybridization indicator or electroactive marker of DNA are reviewed. Special emphasis has been given to the efforts for the development of new transition metal complexes and their interaction to DNA. DNA and polymers covalently conjugated with transition metal complexes were also reviewed.     

双桥连二环戊二烯基金属有机化合物的研究进展

综述了双桥连二戊二烯基金属有机化合物的研究进展，根据桥链以及金属原子 的不同，分别讨论了它们的合成、结构及在催化烯烃聚合上的应用。     

Pincer‐Type Complexes for Catalytic (De)Hydrogenation and Transfer (De)Hydrogenation Reactions: Recent Progress

Pincer complexes are becoming increasingly important for organometallic chemistry and organic synthesis. Since numerous applications for such catalysts have been developed in recent decades, this Minireview covers progress in their use as catalysts for (de)hydrogenation and transfer (de)hydrogenation reactions during the last four years. Aside from noble‐metal‐based pincer complexes, the corresponding base metal complexes are also highlighted and their applications summarized.     

Recent progress of luminescent metal complexes with photochromic units

Photo-responsive molecules have been studied extensively because of their light irradiation abilities that enable modulation of certain physical and chemical properties in emerging molecular electronic and photonic devices. For advanced photonic applications, photochromic metal complexes that have photochromic units as the photo-responsive ligand are highly desirable, as they allow improvement of the photochromic properties and their photo-switching functionality. This article focuses on recent progress in luminescent metal complexes with photochromic units. Luminescence-switching properties of photochromic metal complexes depend on characteristic electronic transitions. The electronic transitions of photochromic metal complexes can be divided into three categories: (1) π–π* transition of the ligand, (2) metal to ligand charge transfer (MLCT) in transition-metal complex, and (3) f–f transition in lanthanide complex. Luminescence modulation using various metal complexes with photochromic units has been studied extensively in recent years, and various applications for future molecular switching devices are expected in the field of advanced photonics. Based on the literature and our studies on luminescent metal complexes with photochromic units, we report on the recent progress of luminescent metal complexes with photochromic units.     

Studies of metal chelates with the novel ligand 2,2,7-trimethyl-3,5-octanedione

The synthesis of the novel ligand 2,2,7-trimethyl-3,5-octanedione, H(tod), is described, as well as the preparation of some of the transition metal and lanthanide complexes containing the anion of this unsymmetrical beta-diketone ligand. The structure of Cu(tod)₂ has been determined by X-ray crystallography to be square-planar with the isobutyl groups cis to each other. Thermogravimetric analyses indicate that several of these metal complexes are volatile and thermally stable compounds. Metal complexes containing this ligand also show unusually high solubilities in non-polar solvents such as n-hexane. The properties of these compounds indicate that they may be useful for vapour-plating of metals, as fuel additives, and in other applications.     

Electrochemical Modified Electrodes Based on Metal‐Salen Complexes

Abstract

A general view of the electroanalytical applications of metal‐salen complexes is discussed in this review. The family of Schiff bases derived from ethylenediamine and ortho‐phenolic aldehydes (N,N′‐ethylenebis(salicylideneiminato)—salen) and their complexes of various transition metals, such as Al, Ce, Co, Cu, Cr, Fe, Ga, Hg, Mn, Mo, Ni, and V have been used in many fields of chemical research for a wide range of applications such as catalysts for the oxygenation of organic molecules, epoxidation of alkenes, oxidation of hydrocarbons and many other catalyzed reactions; as electrocatalyst for novel sensors development; and mimicking the catalytic functions of enzymes. A brief history of the synthesis and reactivity of metal‐salen complexes will be presented. The potentialities and possibilities of metal‐Salen complexes modified electrodes in the development of electrochemical sensors as well as other types of sensors, their construction and methods of fabrication, and the potential application of these modified electrodes will be illustrated and discussed.     

Coordination chemistry of corroles with focus on main group elements

The discovery of facile methodologies for the synthesis of triarylcorroles initiated extensive research on the corresponding metal complexes, ranging from elucidation of their fundamental physical properties to utilization of their chemical reactivity for many applications. This review focuses on the coordination chemistry of main group elements chelated by tetradentate and trianionic 5,10,15-triarylcorroles, which led to the elucidation of unique photophysical, crystallographic and electrochemical characteristics of these complexes. The facile access to a variety of complexes in which these and other properties can be relatively easily tuned allows for the introduction of metallocorroles as key components in advanced systems, such as for photovoltaic cells and imaging procedures in living organism.     

Synthesis,characterization and polymerization of acetylacetate,acetylacetamide or acetylacetanilide substituted cyclic imino ethers,new metal chelating monomers and polymers

New cyclic imino ether monomers, functionalized with acetylacetoxy, acetylacetamide, or acetylacetanilide moieties are described for the first time. These monomers readily form metal complexes. Also, it is shown that these monomers may be cationically homo‐ or copolymerized with other cyclic imino ethers, to provide polymers having metal complexing ability. The monomers have potential applications in a wide variety of applications.     

Chiral organometallic half-sandwich complexes with defined metal configuration

Chiral organometallic half-sandwich complexes with stereogenic metal atoms are close relatives of chiral organic compounds with stereogenic carbon atoms. Similarities and differences between these two classes of compounds are outlined. Some representative metal complexes are discussed in an introductory section followed by a more detailed treatment of the available strategies to control the metal configuration by means of chiral auxiliaries. Special sections are devoted to the discussion of the configurational stability of chiral-at-metal complexes and their applications in stoichiometric and catalytic stereoselective reactions.