RING OPENING COPOLYMERIZATION OF SUCCINIC ANHYDRIDE-ETHYLENE OXIDE BY Al(Ⅲ) ORGANOMETALLIC CATALYSTS

Ring opening copolymerization of succinic anhydride (SA) with ethylene oxide (EO)was successfully carried out by using a series of aluminum-based catalyst in 1,4-dioxane at62±2℃. The results showed that in-situ AlR_3-H_2O (R=ethyl, iso-butyl) catalysts gavehigher molecular weight (M_w～10~4), while Al(OR)_3 catalysts gave the higher alternatingcopolymer structure with slightly lower molecular weight. The in-situ AlR_3-H_2O systemshave been evaluated in more detail for the reaction which showed the optimum H_2O/Almolar ratio to be 0.5. The copolymers with different composition (F_(SA)/F_(EO)= 36/64to 45/55 mol/mol) were synthesized by using different monomer feed ratio. The melt-ing point (T_m), glass transition temperature (T_g) and enthalpy of fusion (ΔH_f) of thesecopolymers are depended on the copolymer composition and in the range of 87～102℃,-12～-18℃, and 37～66J/g, respectively. The second heating scan of DSC also in-dicated that the higher alternating copolymer was more easily recrystallized. The onsetdecomposition temperature was more than 300℃ under nitrogen and influenced by thecopolymer composition.

Novel organometallic aromatic polyester based on ferrocene

A novel polyester containing ferrocenyl was prepared by low-temperature interface polycondensation of 1,1'-ferrocenedicarboxylic acid chloride with 4-(4-hydroxyphenyl)-2,3-phthalazin-1-one(DHPZ),which is a twisted non-coplanar heterocyclic bisphenol-like monomer.The newly generated polymer was evaluated based on characterization of its solubility,viscosity measurements,elemental analysis,FTIR spectroscopy,differential scanning calorimetric and thermogravimetric studies.

X—RAY STRUCTURE OF A SEMICONDUCTING ORGANOMETALLIC SALT,[FeCp(Tol)]_2[Ni(mnt)_2]

The title compound was prepared and characterized.Its crystal Structure was determined by X—ray diffraction analysis,and consists of segregated cation and an- ion stacks in the perpendicular directions.Crystal data:monoclinic,P2_1/c,Mr=765.21, a=7.882(2)b=15.526(4),c=13.736(2)β=99.87(2)~0,V=1656.0(6)~3,Ac =1.53g/cm^3,Z=2,F(000)=780,R=0.040 and R_w=0.056.

Surface Organometallic Chemistry——Surface Supported Triruthenium Ketenylidene Clusters and Their Performance in ^(13)CO Isotopic Exchange and Alkylation Reactions

Recently, metal clusters supported on some solids which simultaneously exhibit many excellent properties of both metal clusters and supports have been intensively studled. Such surface organometallic chemistry, which concerns the synthesis, structure, reactivity and catalytic activity of surface-supported organometallfc compounds is a new

Studies on the Thin Film of TiO_2, Fe_2O_3 and SnO_2 by the Organometallic-CVD Technique

Pure TiO;,Fe;O;and SnO;are wide-bandgap semiconductors.Their films have high transparency in visible spectral region.These oxide films have been applied to electronics,optoelectronics, solar cells and display devices.A variety of techniques including reactive sputtering,reactive evaporation, ion-beam evaporation and chemical vapor deposition, and hydrolyses of the respective halides or alkoxides have been employed for the growth of thin films of TiO;,Fe;O;and SnO;.In

Chemoinformatic Resources for Organometallic Drug Discovery

Medicinal Organometallic Chemistry keeps contributing to drug discovery efforts including the development of diagnostic compounds. Despite the limiting issues of metal-based molecules, e.g., such as toxicity, there are drugs approved for clinical use and several others are under clinical and pre-clinical development. Indeed, several research groups continue working on organometallic compounds with potential therapeutic applications. For arguably historical reasons, chemoinformatic methods in drug discovery have been applied thus far mostly to organic compounds. Typically, metal-based molecules are excluded from compound data sets for analysis. Indeed, most software and algorithms for drug discovery applications are focused and parametrized for organic molecules. However, considering the emerging field of material informatics, the objective of this Commentary we emphasize the need to develop cheminformatic applications to further develop metallodrugs. For instance, one of the starting points would be developing a compound database of organometallic molecules annotated with biological activity. It is concluded that chemoinformatic methods can boost the research area of Medicinal Organometallic Chemistry.

Properties, Characterizations and Applications of Organometallic Surfactants—A Review

This review focuses on organometallic surfactant frameworks considering their wide applications. Organometallic surfactants have grown from being used as dewaxers in complex industrial processes to the production of nanoparticles and for use in many drug delivery applications. Their properties such as self assembly, forming supramolecular structures are outstanding, providing for their myriad industrial usage. In this review, an account of properties, preparation techniques, characterisation techniques and uses of organometallic surfactants are covered.

Synthesis, characterization and photophysical properties of quinolin-8-olato chelated osmium(II) organometallics bearing a pendant imine-phenol motif and electrogeneration of trivalent analogue

The reaction of Os(RL1)(PPh3)2(CO)Br, 1b, with qui-nolin-8-ol (HQ), 2, has furnished complexes of the type [Os(RL2)(PPh3)2(CO)(Q)], 3, in excellent yield (RL1 is C6H2O-2-CHNHC6H4R(p)-3-Me-5, RL2 is C6H2OH-2-CHNC6H4R(p)-3-Me-5 and R is Me, OMe, Cl). In this process, quinolin-8-olato (Q) undergoes five-membered chelation, the iminium-phenolato function tautomerizing to the imine-phenol function. The trans geometry of the Os(PPh3)2 fragment is consistent with the occurrence of a single 31P resonance near –6.0 ppm in 3. In dichloromethane solution, 3 displays a quasireversible 3+/3 couple near 0.40 V vs. SCE (3+ is the osmium (III) analogue of 3). Coulometrically generated solutions of 3+ displays a strong absorption near 340 nm, 415 nm and 500 nm and are one-electron paramagnetic (low-spin d5, S = 1/2) and show rhombic EPR spectra in 1:1 dichloromethanetoluene solution at 77 K with g values near 2.44, 2.20, 1.83. Distortion parameters using the observed g values have been computed. Solutions of 3 absorb near 420 nm and emit near 510 nm at 298 K and 580 nm at 77 K. The fluorescence is believed to originate from the 3MLCT state.

Two-Dimensional Organometallic TM3–C12S12 Monolayers for Electrocatalytic Reduction of CO2

Organometallic nanosheets are a versatile platform for design of efficient electrocatalyst materials due to their high surface area and uniform dispersion of metal active sites.In this paper,we systematically investigate the electrocatalytic performance of the first transition metal series TM3–C12S12 monolayers on CO2 using spin-polarized density functional theory.The calculations show that M3–C12S12 exhibits excellent catalytic activity and selectivity in the catalytic reduction in CO2.The main reduction products of Sc,Ti,and Cr are CH4.V,Mn,Fe and Zn mainly produce HCOOH,and Co produces HCHO,while CO is the main product for Ni and Cu.For Sc,Ti,and Cr,the overpotentials are>0.7 V,while for V,Mn,Fe,Co,Ni,Cu,Zn,the overpotentials are very low and range from 0.27 to 0.47 V.Therefore,our results indicate that many of the M3–C12S12 monolayers are expected to be excellent and efficient CO2 reduction catalysts.

Crystal Structure of Organometallic Complex[Zn (pom)_2I_2]

The title complex [Zn (pom)_2I_2] (pom = 3-Methyl-4-Nitropyridine-1Oxide), C_(12)H_(12)N_4O_6I_2Zn, M_r= 627. 43, triclinic, space group P1, a= 11. 301 (2), b=13. 561(2) , c=6. 792(1) A, α=101. 29(1), β=96. 87(2), γ= 107. 13(1)°, V=957. 80(62) A￣3, Z=2, D_c=2. 175 g/cm￣3, λ(MoKa)=0. 71069 A, μ=45. 4 cm(-1),F (000) = 592, T= 296K, R(R_w) is 0. 068 (0. 078) for 2556 observed unique reflections. The structure of the complex is isolated and three-dimensional.

An Ultralong Low-Temperature Phosphorescent Pentagonal-Prismatic Organometallic Cylinder Featuring Pentaphenylpyrrole-N-Heterocyclic Carbenes

A pentagonal-prismatic cylinder[Ag5(L)2](PF6)5 obtained from the pentaphenylpyrrole-bridged pentaimidazolium salt H5-L(PF6)5 and AgI ions was determined by X-ray diffraction analyses.The target organometallic cylinder not only exhibited enhanced fluorescence emission in dilute solution at room temperature but also showed an improved phosphorescence ratio compared with the free precursor and maintained a long lifetime(1.39 s)in the solid state at 77 K.Furthermore,the experimental results and DFT calculations confirmed that the formation of the organometallic cylinder promoted intersystem crossing.Meanwhile,the frontier orbitals of[Ag5(L)2](PF6)5 showed the main contribution of building block PPP as the luminescence source of[Ag5(L)2](PF6)5 by a modest heavy-atom effect.These results provide a strategy for constructing enhanced phosphorescent emission and long lifetime organometallic supramolecular phosphorescent materials.

Radical organometallic nanocages with redox switchable poly-NHC ligands

Developing discrete radical organometallic nanocages is essential for fabricating functional materials.In this study,we construct a series of poly-NHC-based(NHC=N-heterocyclic carbene)organometallic nanocages 3a-3c with different sizes by employing redox-active bis(triarylamine)derivatives with differentπ-conjugated spacers as building blocks.The varied sizes of nanocages 3a-3c modulate the distance of the redox-active centers and reversibly convert them to radical nanocages 3a^(2+)-3c^(2+)through chemical and electrochemical oxidation.Radical nanocages 3a^(2+)-3c^(2+)display clear bond and angle alteration and retention of their three-dimensional topologies.This work not only merely proves that these nanocages are excellent stimulus-responsive materials but also opens a door to the rational design of novel radical organometallic nanocages.

In Situ Supramolecular Polymerization via Organometallic-Catalyzed Macromolecular Metamorphosis

Integrating catalytic reactions with molecular assembly is a promising means of achieving controllable supramolecular polymerization.We report herein a novel and controllable method for in situ supramolecular polymerization via organometallic-catalyzed macromolecular metamorphosis.To this end,covalent polymers with polypentenamer backbones and pendant supramolecular motifs are designed and synthesized.By depolymerizing the polymers with Grubbs catalysts,the supramolecular motifs can be gradually released from the polymers to the solution.Supramolecular polymerization occurs when a critical concentration is reached.The supramolecular polymerization process was readily controlled by varying the rate of the depolymerization reaction.This work presents a novel approach that uses organometallic catalysis to transform covalent polymers into supramolecular polymers.It offers a new means of constructing complex molecular systems in a controllable manner.

Modification of the adsorption and catalytic properties of micro-and mesoporous materials by reactions with organometallic complexes

This review describes the work of two laboratories in the field of the modification of micro-and mesoporous molecular sieves through reactions with organometallic complexes.The modification of zeolites can occur inside the pore channels or on the external surface,depending on the size of the organometallic complex.When the modification occurs on the external surface,it results in a decrease of the pore entrance,which will lead in turn to a modification of the sorption properties of the zeolite,by decreasing the rate of the adsorption(mainly by a kinetic control).Such a material can be also used in catalysis,because the external acid sites,which are responsible for side-reactions,have been removed upon grafting.When small organometallic complexes are used,they can fill the channels and cages of the zeolite and react with internal hydroxyl groups.Due to the high acidity of zeolites,the reaction occurs very easily(for example at-100℃ on faujasite),in contrast to what is observed on the external surface,therefore leading to high metal loadings.In that case,the modification of the sorption properties will be mainly related to a thermodynamic control.The resulting materials can be useful in catalysis,by combining the activity of the organometallic complex and properties(for example shape-selectivity) of the zeolite.Modification of mesoporous molecular sieves occurs always in the pores and results in altering of the sorption properties of the solid,by changing the interaction type between the sorbent and the sorbate.For example the sorption isotherm of alkanes is changed from type II to type III according to the IUPAC nomenclature.

POLYMERIZATION OF LACTIC O-CARBOXYLIC ANHYDRIDE USING ORGANOMETALLIC CATALYSTS

The ring-opening polymerization of 5-methyl-1,3-dioxolane-2,4-dione（lactic O-carboxylic anhydride,LacOCA） using organometallic complexes,including Co（Ⅲ） complexes with Schiff base ligands,Tin（Ⅱ） alphatates and Al（Ⅲ） complexes with Schiff base ligands,was explored.The polymerization was carried out by treatment of the organometallic complexes with LacOCA in toluene under mild conditions.The corresponding poly（lactic acid） was characterized by spectroscopy and thermal analyses,which revealed insight into the structure of the effective catalyst for the polymerization of LacOCA.

Study of Direct Synthesis of Organometallic Polymer Films and Their Conduction Properties

It is generally necessary to prepare an organometallic polymer in two steps: first synthesizing the organometallic monomer, and then polymerizing it. However, problems still remain in the syntheses of organometallic monomers and their stability. The monomers available for organometallic polymerization are limited. To solve the problem of scarcity of monomers, we have developed a new method of preparing

The synthesis and characterization of organometallic copolymers with Mn-Re binuclear transition-metal group in the side chain

Novel organometallic copolymers with Mn-Re binuclear transition-metal groups in the side chain are synthesized and characterized. The structure and properties of the copolymers are characterized by GPC, DSC, TG, NMR, FT-IR, UV-Vis spectra and elemental analysis. The glass transition temperature and UV-Vis spectra properties of these three organometallic copolymers are found to be different from the normal polystyrene. New synthetic strategy for the synthesis of or-ganometallic copolymer is developed.

Functional Organometallics

1 Results The lecture will address aspects of functional organometallics related to the development of novel organometallic materials.In chromium complexes of fused arenes-regio-and diastereoselectively accessible by chromium-templated benzannulation of arylcarbenes by alkynes[1]-a haptotropic migration of the chromium fragment along the π-face of fused arenes is controlled by both thermodynamics and the substitution pattern of the arene and the metal coligand sphere,and can be applied towards an organo...

Surface Organometallic Chemistry for Single-site Catalysis and Single-atom Catalysis

Although driven by different research interests,single-site catalysts and single-atom catalysts are both believed to be model systems bridging homogeneous and heterogeneous catalysis.The two concepts are similar but different.In this review,we will first explain the difference between single-atom catalysis and single-site catalysis,in terms of their goals,synthetic methods and coordination structures of corresponding catalysts.Then,we will introduce the surface organometallic chemistry method,a method traditionally used for synthesizing single-site catalyst.We will explain why it might benefit the single-atom catalysis community.At last,the choice of support to accommodate the method for synthesizing single-atom catalysts will be discussed.

Fabrication of stable organometallic halide perovskite NWs based optoelectronic devices

Organometallic halide perovskite materials have triggered global attention in recent years due to their exciting and optimistic high performance energy conversion properties(high luminescence efficiency and tremendous optical absorption ability[1,2]).These interesting photovoltaic properties together make them a promising candidate for high performance optoelectronic