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.     

γ-取代-β-二酮二羰基合铑的合成与介晶性

合成了体系中含一个苯环、二个苯环的γ-取代-β二酮二羰基合铑棒状金属有机化合物, 并对其介晶性进行了表征。探讨了分子长宽比、刚性实和结构对液晶性质的影响。同时表明了向列相有机液晶分子的模型设计同样能很好地指导金属有机液晶分子的设计、合成及介晶性行为的研究。     

Predication of second-order optical nonlinearity of [(Bu2t Im)AuX] (X=halogen) using time-dependent density-functional theory combined with sum-over-states method

The dipole polarizability and second-order polarizability of recently synthesized (1,3-di-ter-butylimidazol-2-ylidine) gold complexes [(Bu2t Im)AuX] (X=halogen) were investigated by using time-dependent density-functional theory combined with sum-over-states method. We have discovered that these complexes possess remarkably larger molecular second-order polarizability compared with the organometallic and organic complexes. The value of the second-order polarizability increases in the order of F相似文献   

Manganese(II): the black sheep of the organometallic family

The organometallic chemistry of manganese in the +2 oxidation state is distinct from the organometallic chemistry of a 'typical' transition metal due to a significant ionic contribution to the manganese(II)-carbon bonds. The reduced influence of covalency and the 18-electron rule result in organomanganese(II) cyclopentadienyl, alkyl and aryl complexes possessing reactivity and structural diversity that is unique in organotransition metal chemistry. Recently, this unusual reactivity has resulted in a range of novel applications in selective organometallic and organic synthesis, and polymerization catalysis. This tutorial review summarizes key milestones in the development of manganese(II) organometallics and discusses how some of their current synthetic applications have evolved from many fascinating fundamental studies in the area.     

Triaryl-1,3,5-triazinane-2,4,6-triones functionalized with electron-rich Fe(II) and Ru(II) acetylide complexes: new organometallic octupoles with large hyperpolarizabilities

The synthesis and study of a series of trinuclear organometallic triaryl-1,3,5-triazinane-2,4,6-triones functionalized by d(6)-transition metal acetylides complexes at their periphery are reported. Remarkably large hyperpolarizabilities, far superior to those of related purely organic derivatives, are measured by hyper-Rayleigh scattering (HRS) for these new octupolar chromophores.     

金属有机电致磷光材料研究进展

综述了近几年来用于有机发光二极管中的金属有机电致磷光材料的研究进展, 重点评述了重金属铱配合物、稀土元素配合物和含金属配合物的聚合物磷光材料近年来的研究进展, 展望了金属有机配合物电致磷光材料的发展前景.     

Chiral monomeric organorhenium(VII) and organomolybdenum(VI) compounds as catalysts for chiral olefin epoxidation reactions

Several attempts have been made to transform the organometallic Re(VII) compound MTO and the (MoO₂)²⁺ moiety to chiral epoxidation catalysts by addition of chiral organic ligands. Being very efficient epoxidation catalysts in achiral reactions, it was hoped that these compounds could be transformed into chiral epoxidation catalysts by adding chiral Lewis base ligands. The major flaw of most of these attempts, however, was the weak coordination of the chiral Lewis base ligands to the metal center, which led either to high ees only at the very beginning of the catalytic reaction (low conversion) or to generally low enantiomeric excesses. The heterogenisation of the Mo(VI) complexes was, at least in some cases, successfully achieved but with the same drawbacks with respect to the ees as in the homogeneous phase. Currently, attempts are being made to synthesize organometallic Re(VII) and Mo(VI) complexes with stronger interactions between the metal containing moiety and the chiral ligand(s).     

Oxovanadium(IV) and dioxomolybdenum(VI) salen complexes tethered onto amino-functionalized SBA-15 for the epoxidation of cyclooctene

Oxovanadium(IV) and dioxomolybdenum(VI) salen complexes were firstly tethered onto amino-functionalized mesoporous SBA-15 materials by a stepwise procedure and were screened as catalysts for the epoxidation of cyclooctene. The mesoporous structural integrity throughout the tethering procedure, the successful tethering of the organometallic complexes, the loadings of metal ions and organic ligands as well as the catalyst surface constitution and location of active organometallic species on the SBA-15 support were determined by comprehensive characterization techniques such as XRD, N₂ adsorption/desorption, FT-IR, UV–vis spectroscopy, ICP-AES, XPS and TG/DTA. Catalytic properties in the epoxidation of cyclooctene demonstrate that both tethered oxovanadium(IV) and dioxomolybdenum(VI) catalysts were more active than their respective homogeneous analogue, and the tethered oxovanadium(IV) complex showed the best activity (64.3%) with H₂O₂ as the oxidant and CH₃CN as the solvent.     

Optically active organometallic compounds (a personal account from the inside)

Results of a long experience of our group in Moscow in the area of chiral organometallic stereochemistry are described. They embrace optically active organometallic derivatives of mercury, palladium, platinum, functionalized ferrocenes, ruthenocenes, and cymantrenes as well as less common objects such as organometallic fullerenes and the cyclodextrin-metallocenes inclusion complexes.     

Multiple reactivities of dithranol towards 1-alkynyl Fischer carbene complexes (CO)5MC(OEt)CCPh (M = Cr, W) - Efficient chemical synthesis of aromatic polyketides

Reactions of anti-psoriasis drug dithranol with 1-alkynyl Fischer carbene complexes (CO)₅MC(OEt)CCPh (M = Cr, W) were investigated under controlled conditions in which triethylamine-promoted C-addition, O-addition, electrophilic aromatic substitution, and cyclization consecutively occurred at up to five positions of dithranol. A remarkable solvent effect led to selective formation of polyphenolic organic and organometallic mono- and triscarbene complexes which were efficiently demetalated to the potentially bioactive aromatic polyketides with pyridine-N-oxide. All the organic and organometallic products were characterized by methods including X-ray single crystal structural determinations. These results have revealed the novel multiple reactivities of dithranol which might be associated to its clinical side effect, providing a new synthetic methodology to functionalize dithranol for medical purposes, and chemically synthesize aromatic polyketides.     

液态聚乙二醇作为绿色反应介质在有机反应中的应用*

低分子量的液态聚乙二醇（PEG）作为一种新型的绿色有机反应溶剂正受到人们的极大关注。PEG具有好的热稳定性、不挥发、不易燃、无毒、生物可降解、廉价易得,以及易于回收和循环使用。此外,PEG可以溶解众多的有机化合物和有机金属配合物。因此,PEG作为有机溶剂的替代品和作为均相催化剂的载体已经成功地应用到许多有机反应中,它们包括还原反应、氢化反应、氧化反应、不对称双羟基化反应、Heck反应、Suzuki交叉偶联反应、Michael加成反应、不对称Aldol反应、Baylis-Hillman反应、脂肪酶催化的反应和聚合反应等。本文对这一领域的研究进展作一综述。     

Synthesis and characterization of semicarbazone metal complexes of Sn(IV) and Zr(IV)

Three semicarbazonyl ligands were synthesized and used to form six novel organometallic complexes with Ph2SnCl2 and Cp2ZrCl2. All these complexes were characterized by IR,1H NMR,MS and elemental analysis.     

Protein Staining Agents from Cationic and Neutral Luminescent Iridium(III) Complexes

Seven luminescent iridium(III) complexes were prepared to investigate the relationships between chemical structures and properties of protein staining. For the first time, the effect of the main ligand, the π conjugation effect of the ancillary ligand, and the charge effect of organometallic complexes on protein staining has been revealed. Most importantly, this study gives the first experimental evidence of the potential applications of charge‐neutral organometallic complexes in protein staining, which could open an avenue of exploiting novel protein staining agents in the future.     

Enhancing heterogeneous catalysis through cooperative hybrid organic-inorganic interfaces

Active-site/surface cooperativity can enhance heterogeneous organic and organometallic catalysis. We review the powerful role of the solid surface in this context for generating local acidity and, as an inner-sphere ligand, for stabilizing immobilized supramolecular assemblies and unsaturated organometallic complexes that are often unstable in solution.     

Stable gold(III) complexes with thiosemicarbazone derivatives

Novel thiosemicarbazonato complexes of gold(III) have been prepared from reactions of [Au(damp-C1,N)Cl2(damp- = 2-(N,N-dimethylaminomethyl)phenyl) or [NBu4][AuCl4] with 2-pyridineformamide thiosemicarbazones (HL). The thiosemicarbazones deprotonate and coordinate as mononegative, tridentate NNS ligands to gold to give [Au(Hdamp-C1)(L)]Cl2 or [AuCl(L)]Cl complexes. The organometallic damp- ligand is protonated during the reactions and the Au-N bond is cleaved. The [AuCl(L)]+ cations represent the first gold(III) complexes with thiourea derivatives which are not stabilised by an additional organometallic ligand. Reactions of [NBu4][AuX4](X = Cl, Br) with diphenylthiocarbazone (dithizone) result in reduction of the metal and the formation of gold(I) complexes of the composition [AuX(SCN4-3,4-Ph2)] where SCN4-3,4-Ph2 is 3,4-diphenyltetrazole thione which is formed from cyclisation of dithizone.     

The effect of solvent upon the rates and mechanisms or organometallic rections. : I. General aspects

The data reported to date on the effect of solvent upon the rates and mechanisms of organometallic reactions have been analysed and discussed and indicate that the effect is very complex. The analysis also shows that there is no overall explanation for the effect and that indeed such an explanation seems at present to be non-existent.It is suggested that the problem may be successfully approached through a study of the effect of the solvent upon the redistribution of organic groups between organometallic molecules. In these reactionis, not only the kinetics of the reactions in various solvents should be studied but also identification of the organometallic complexes is essential as well as the electronic structures and geometries of the complexes in the crystalline phase and in solution.     

The story of silica-supported Os3(CO)12 a molecular approach to heterogeneous catalysis

The surface organometallic chemistry can be defined as the study of the reactivity of organometallic complexes, in particular molecular metals carbonyl clusters, with the surface of microporous metal oxides and, by extension, of zeolites.     

Application of size exclusion chromatograph (sec) to organometallic compounds

The utility of modern size-exclusion chromatography for the separation and identification of organometallic compounds is described with examples from studies on low-valent complexes of nickel and iron.     

Synthesis,Structure and Reactivity of Sulfur-Rich Cyclopentadienyl-Transition Metal Complexes: Sulfur Chemistry from an Organometallic Point of View

Metal-sulfur centers play an important role in the activity of metalloproteins in enzymatic catalysis and the activity of metal sulfides as heterogeneous catalysts. The systematic search for M? S model compounds led to the discovery of an interesting and novel structural chemistry, which stems from the numerous coordination possibilities of sulfur ligands. The intention of this review article is to present and outline new approaches to sulfur chemistry from the organometallic point of view. Reactive cyclopentadienyl-transition metal fragments incorporate elemental sulfur to give polynuclear sulfur-rich complexes, which can contain either mono-, di- or polysulfido ligands or several such ligands in combined form. The versatile structural chemistry of the complexes formed and their reactivity towards organic, inorganic and organometallic compounds are discussed, and examples of some simple and rational procedures for their synthesis starting from cyclopentadienylcarbonyl- and cyclopentadienylhydrido-complexes are outlined. Their reactivity is manifested in numerous metal- and ligandcentered reactions. Finally the, albeit far less extensive, complex chemistry of the other chalcogens (O, Se, Te) is also considered for comparison, thus providing a more detailed survey of particular aspects of this area of chemistry.     

Ligand acyle et ligand alkoxycarbonyle: couplage carbone-carbone ou isomérie cycle-chaîne sur l’exemple des complexes octaédriques du fer du type cis-Fe{[C(O)]xR} {[C(O)]yR′}(CO)4; x,y = 0,1; R ou R′ = CH3, OCH3

This paper concerns the analogies and the differences of behaviour between organometallic ligands and their organic homologues. The study of the carbon-carbon coupling process inducing the formation of mono or bis carbonylated organic compounds, as well as the ring-chain isomerization giving rise to five membered metallacyclic complexes, were realized on a homogeneous series of iron octahedral complexes bis substituted by two carbonylated organic ligands.