Jun Peng

Bio: Jun Peng is an academic researcher from Northeast Normal University. The author has contributed to research in topics: Polyoxometalate & Isostructural. The author has an hindex of 37, co-authored 215 publications receiving 5522 citations. Previous affiliations of Jun Peng include Chinese Academy of Sciences.

Assembly of the Highest Connectivity Wells-Dawson Polyoxometalate Coordination Polymer: the Use of Organic Ligand Flexibility

Abstract: Through tuning the length of flexible bis(triazole) ligands and different metal ion coordination geometries, four Wells-Dawson polyoxoanion-based hybrid compounds, [Cu6(btp)3(P2W18O62)]·3H2O (1) (btp = 1,3-bis(1,2,4-triazol-1-y1)propane), [Cu6(btb)3((P2W18O62)]·2H2O (2), [Cu3(btb)6(P2W18O62)]·6H2O (btb = 1,4-bis(1,2,4-triazol-1-y1)butane) (3), and [Cu3(btx)5.5((P2W18O62)]·4H2O (btx = 1,6-bis(1,2,4-triazol-1-y1)hexane) (4), were synthesized and structurally characterized. In compound 1, the metal-organic motif exhibits a ladder-like chain, which is further fused by the ennead-dentate [P2W18O62]6− anions to construct a 3D structure. In compound 2, the metal-organic motif exhibits an interesting Cu−btb grid layer, and the ennead-dentate polyoxoanions are sandwiched by two Cu−btb layers to construct a 3D structure. Compound 3 exhibits a (42·62·82) 3D Cu−btb framework with square and hexagonal channels arranged alternately. The hexa-dentate polyoxoanions incorporate only into the hexagonal channels. In compoun...

Tuning the Dimensionality of the Coordination Polymer Based on Polyoxometalate by Changing the Spacer Length of Ligands

Abstract: Through tuning the spacer length of flexible bis(triazole) ligands, three Keggin anion-based coordination polymers with different dimensionalities, [Cu4(H2O)4(bte)2(HPMoVI10MoV2O40)]·2H2O (1) (bte = 1,2-bis(1,2,4-triazol-1-yl)ethane), [Cu(btb)][Cu2(btb)2(PMo12O40)] (2) (btb = 1,4-bis(1,2,4-triazol-1-y1)butane), and [Cu5(btx)4(PMoVI10MoV2O40)] (3) (btx = 1,6-bis(1,2,4-triazol-1-y1)hexane), were synthesized and structurally characterized. Compound 1 exhibits a ladder-like chain, in which the polyoxometalate (POM) anions act as the “middle rails” of the ladder. The bte ligand with shortest spacer length acts as not only the bridging linker but also the chelator, which terminates the dimensional extension. Compound 2 exhibits a 2D POM-based framework, containing POM/Cu/btb grid-like layers. In compound 3, there exist three sets of (123)(121)2 2D Cu-btx frameworks to generate a 3-fold interpenetrating structure, into which the hexadentate POM anions are inserted to construct a 3D structure. The structural anal...

Assemblies of Copper Bis(triazole) Coordination Polymers Using the Same Keggin Polyoxometalate Template

Abstract: Four inorganic−organic hybrid compounds, [CuI4(bte)4(SiW12O40)] (1), [CuII2(bte)4(SiW12O40)]·4H2O (2) [bte = 1,2-bis(1,2,4-triazol-1-yl)ethane], [CuI4(btb)2(SiW12O40)]·2H2O (3), and [CuII2(btb)4(SiW12O40)]·2H2O (4) [btb = 1,4-bis(1,2,4-triazol-1-yl)butane], were hydrothermally synthesized through use of the same Keggin polyoxometalate as the template and tuning the molar ratio of the bis(triazole) ligand to the CuII ion. The ratio of the bis(triazole) ligand to CuII has a crucial influence on the structures of this series. Single-crystal X-ray diffraction analyses indicate that compound 1 is constructed by tetranuclear ring-connecting chains and polymerized [Cu(bte)]+ chains, between which SiW12 anions are inserted to form a three-dimensional (3D) structure. Compound 2 shows a (44·62) two-dimensional grid sheet. The discrete SiW12 anions are sandwiched by the sheets, just like “hamburgers”. Compound 3 presents channel-like [Cu2(btb)]2+ polymerized chains, which are further connected by SiW12 anions to con...

High-Dimensional Assembly Depending on Polyoxoanion Templates, Metal Ion Coordination Geometries, and a Flexible Bis(imidazole) Ligand

Abstract: By introducing the flexible 1,1‘-(1,4-butanediyl)bis(imidazole) (bbi) ligand into the polyoxovanadate system, five novel polyoxoanion-templated architectures based on [As8V14O42]4- and [V16O38Cl]6- building blocks were obtained: [M(bbi)2]2[As8V14O42(H2O)] [M = Co (1), Ni (2), and Zn (3)], [Cu(bbi)]4[As8V14O42(H2O)] (4), and [Cu(bbi)]6[V16O38Cl] (5). Compounds 1−3 are isostructural, and they exhibit a binodal (4,6)-connected 2D structure with Schlafli symbol (34·42)(34·44·54·63)2, in which the polyoxoanion induces a closed four-membered circuit of M4(bbi)4. Compound 4 exhibits an interesting 3D framework constructed from tetradentate [As8V14O42]4- cluster anions and cationic ladderlike double chains. There exists a bigger M8(bbi)6O2 circuit in 4. The 3D extended structure of 5 is composed of heptadentate [V16O38Cl]6- anions and flexural cationic chains; the latter consists of six Cu(bbi) segments arranged alternately. It presents the largest 24-membered circuit of M24(bbi)24 so far observed made of bbi mo...

pH-Dependent Assembly of Hybrids Based on Wells-Dawson POM/Ag Chemistry

Abstract: Four new hybrids based on the Wells-Dawson polyoxometalate [P2W18O62]6− (P2W18), {[Ag(bipy)]2[P2W18O62]}·2[H2bipy]·4H2O (1), {[Ag(bipy)]4[P2W18O62]}·2[Hbipy] (2), K[P2W18O62]·2.5[H2bipy]·2H2O (3), and [P2W18O62]2·[H2bipy]4·[Hbipy]4·3H2O (4), were hydrothermally synthesized and structurally characterized by routine techniques and single-crystal X-ray diffraction. Compounds 1 and 2 are isolated at lower pH values. 1 represents a 3D (4,4)-net structure with NbO topology, in which the P2W18 clusters are modified by four Ag−N coordination polymeric chains, and 2 exhibits a 3D (3,4)-net structure with the (92·12)(8·104·12)(32·102·112)(3·6·102·122) topology, in which Ag-bipy layers are intercalated by the dimer of P2W18 clusters in a staggering mode, and the P2W18 clusters show the highest coordination number to date. By increasing the pH value, compounds 3 and 4 are obtained as supramolecular compounds. Their structural differences reveal that the pH value of the reaction system is the key factor influencing th...

Synthesis of Light-Emitting Conjugated Polymers for Applications in Electroluminescent Devices

Abstract: A review was presented to demonstrate a historical description of the synthesis of light-emitting conjugated polymers for applications in electroluminescent devices. Electroluminescence (EL) was first reported in poly(para-phenylene vinylene) (PPV) in 1990 and researchers continued to make significant efforts to develop conjugated materials as the active units in light-emitting devices (LED) to be used in display applications. Conjugated oligomers were used as luminescent materials and as models for conjugated polymers in the review. Oligomers were used to demonstrate a structure and property relationship to determine a key polymer property or to demonstrate a technique that was to be applied to polymers. The review focused on demonstrating the way polymer structures were made and the way their properties were controlled by intelligent and rational and synthetic design.

Polyoxometalate clusters, nanostructures and materials: From self assembly to designer materials and devices

Abstract: Polyoxometalates represent a diverse range of molecular clusters with an almost unmatched range of physical properties and the ability to form structures that can bridge several length scales. The new building block principles that have been discovered are beginning to allow the design of complex clusters with desired properties and structures and several structural types and novel physical properties are examined. In this critical review the synthetic and design approaches to the many polyoxometalate cluster types are presented encompassing all the sub-types of polyoxometalates including, isopolyoxometalates, heteropolyoxometalates, and reduced molybdenum blue systems. As well as the fundamental structure and bonding aspects, the final section is devoted to discussing these clusters in the context of contemporary and emerging interdisciplinary interests from areas as diverse as anti-viral agents, biological ion transport models, and materials science.

Polyoxometalates: Building Blocks for Functional Nanoscale Systems

Abstract: Polyoxometalates (POMs) are a subset of metal oxides that represent a diverse range of molecular clusters with an almost unmatched range of physical properties and the ability to form dynamic structures that can range in size from the nano- to the micrometer scale Herein we present the very latest developments from synthesis to structure and function of POMs We discuss the possibilities of creating highly sophisticated functional hierarchical systems with multiple, interdependent, functionalities along with a critical analysis that allows the non-specialist to learn the salient features We propose and present a "periodic table of polyoxometalate building blocks" We also highlight some of the current issues and challenges that need to be addressed to work towards the design of functional systems based upon POM building blocks and look ahead to possible emerging application areas

Hybrid Organic−Inorganic Polyoxometalate Compounds: From Structural Diversity to Applications

Abstract: Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments. They exhibit a great diversity of sizes, nuclearities, and shapes. They are built from the connection of {MOx} polyhedra, M being a d-block element in high oxidation state, usually VIV,V, MoVI, or WVI.1 While these species have been known for almost two centuries, they still attract much interest partly based on their large domains of applications. They play a great role in various areas ranging from catalysis,2 medicine,3 electrochemistry,4 photochromism,5 to magnetism.6 This palette of applications is intrinsically due to the combination of their added value properties (redox properties, large sizes, high negative charges, nucleophilicity...). Parallel to this domain, the organic-inorganic hybrids area has followed a similar expansion during the last 10 years. The concept of organic-inorganic hybrid materials * To whom correspondence should be addressed. E-mail: dolbecq@ chimie.uvsq.fr. Chem. Rev. 2010, 110, 6009–6048 6009