Synthesis,dynamic light scattering,and luminescence properties of copolymers containing iridium(III) bisterpyridine in the side chain

Supramolecular block‐random copolymers containing [Ir(terpy)₂]³⁺ in the side chain were synthesized via postfunctionalization of a P(S‐b‐AC_terpy) block copolymer. Absorbance and emission spectra compared to a model compound show that the polymer backbone has a minor effect on the polymer absorbance but produces a larger shift for the phosphorescence signals to higher wavelength. Dynamic light scattering of the metal complex containing copolymer studied in various solvents showed monomodal aggregation with decreasing aggregate size as the solvent dielectric constant increased. The copolymer precursor P(S‐b‐AC_terpy) shows multimodal aggregation in different solvents with the major population consisting of single chains. This difference in behavior between the two polymers is attributed to the electrolytic nature of the complex and the amphiphilicity induced by the charged metal complex. Supramolecular copolymers like these will continue to have interesting self‐organizational properties and may find applications in multicomponent systems for photoinduced charge separation processes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1109–1121, 2007     

Characterization of Metallo Bis(terpyridine) Diblock Polymers by Nonaqueous Capillary Zone Electrophoresis

A method of nonaqueous capillary zone electrophoresis (CZE) has been developed to characterize block (co)polymers of poly(ethylene oxide) and poly(styrene) containing metallo bis(terpyridine) complexes as bridging units. Specific CZE separation conditions had to be applied, with barium perchlorate dissolved in N-methylformamide (NMF) as background electrolyte and OV-1701-OH deactivated capillaries. For detection UV absorption was measured at a wavelength of 316 nm. Metallo diblock polymers with molecular weights up to 30,000 Da could be analyzed by the proposed nonaqueous CZE method. Experiments performed with polymeric compounds containing Fe, Ni or Ru as central metal ions showed that their electrophoretic mobilities were independent of the type of metal ion. Therefore, the data on the size of the polymeric compounds could be obtained using just one set of calibration standards. Polydispersities of the samples calculated from the experimental results were in correlation with the polydispersities of the polymers used in the synthesis of the metallo diblock polymers. Several polymeric samples contained metallo mono(terpyridine) complexes as impurities. These by-products could be separated from the main product. With symmetrical diblock polymers only one by-product was detected, while with an asymmetric diblock polymer two types of mono-complexes were found. The amount of the mono-complexes present as impurities was dependent on the type of central metal ion (Ni > Fe >> Ru).     

Photophysical Studies on Terpyridine-Eu3+ Complexes in Sol-Gel Nanocomposite Materials

The luminescence of the terpyridine-Eu³⁺-complex associated with poly(ethyleneoxide) or poly(propyleneoxide) chains has been studied in various fluid or solid environments including silica/poly(alkyleneoxide) nanocomposite materials. Strongly luminescent materials are obtained. Their emission can be tuned by varying the organic/inorganic content and, generally, the structure of the host material. In this respect, the complex luminescence itself is a sensor of the structural aspects of the host material.     

Synthesis of Molecular Wires of Linear and Branched Bis(terpyridine)‐Complex Oligomers and Electrochemical Observation of Through‐Bond Redox Conduction

Films of linear and branched oligomer wires of Fe(tpy)₂ (tpy=2,2′:6′,2′′‐terpyridine) were constructed on a gold‐electrode surface by the interfacial stepwise coordination method, in which a surface‐anchoring ligand, (tpy? C₆H₄N?NC₆H₄? S)₂ ( 1 ), two bridging ligands, 1,4‐(tpy)₂C₆H₄ ( 3 ) and 1,3,5‐(C?C? tpy)₃C₆H₃ ( 4 ), and metal ions were used. The quantitative complexation of the ligands and Fe^II ions was monitored by electrochemical measurements in up to eight complexation cycles for linear oligomers of 3 and in up to four cycles for branched oligomers of 4 . STM observation of branched oligomers at low surface coverage showed an even distribution of nanodots of uniform size and shape, which suggests the quantitative formation of dendritic structures. The electron‐transport mechanism and kinetics for the redox reaction of the films of linear and branched oligomer wires were analyzed by potential‐step chronoamperometry (PSCA). The unique current‐versus‐time behavior observed under all conditions indicates that electron conduction occurs not by diffusional motion but by successive electron hopping between neighboring redox sites within a molecular wire. Redox conduction in a single molecular wire in a redox‐polymer film has not been reported previously. The analysis provided the rate constant for electron transfer between the electrode and the nearest redox‐complex moiety, k₁ (s^?1), as well as that for intrawire electron transfer between neighboring redox‐complex moieties, k₂ (cm² mol^?1 s^?1). The strong effect of the electrolyte concentration on both k₁ and k₂ indicates that the counterion motion limits the electron‐hopping rate at lower electrolyte concentrations. Analysis of the dependence of k₁ and k₂ on the potential gave intrinsic kinetic parameters without overpotential effects: k₁⁰=110 s^?1, k₂⁰=2.6×10¹² cm² mol^?1 s^?1 for [n Fe 3 ], and k₁⁰=100 s^?1, k₂⁰=4.1×10¹¹ cm² mol^?1 s^?1 for [n Fe 4 ] (n=number of complexation cycles).     

Dialing in color with rare earth metals: facile photoluminescent production of true white light

Combining polymeric architectures with metal ions produces hybrid materials with extremely rich properties. We are studying polymers containing terpyridine in the side chain. In this report, the chelation of lanthanide ions, Eu³⁺, Tb³⁺, and Dy³⁺ resulted in metal functionalized copolymers that exhibited excellent emission of red, green, and blue light respectively. The polymer architecture easily allows incorporation of all three colors into the material, which leads to the facile production of true white light in solution or the solid state. Quantum efficiencies for the polymer systems were determined. The white light system had an efficiency of 5%. Various combinations of colors were achieved from the basic RBG colors by simply varying the metal ion ratios in the polymer backbone. This easy tuning of the color makes these systems attractive. Copyright © 2007 John Wiley & Sons, Ltd.     

Mercury(II) complex with terpyridine: structure of the 2∶1 solvate of [Hg(terpy)2](CF3SO3)2 with acetone

[Hg(terpy)₂](CF₃SO₃)₂·0.5(CH₃)₂CO crystallizes in the triclinic space group witha=14.631(6),b=15.258(4),c=18.785(7) Å, =69.66(2), =70.72(1), =88.55(1)°. The crystal structure consists of two independent [Hg(terpy)₂]²⁺ cations, four trifluoromethanesulfonate anions and an acetone molecule in the asymmetric unit. Each mercury atom is coordinated by two tridentate terpyridine ligands forming an irregular six-coordination polyhedron. The Hg–N bond lengths range from 2.27(2) to 2.53(2) Å.     

Synthesis of bipyridine and terpyridine based ruthenium metallosynthons for grafting of multiple pyrene auxiliaries

The synthesis of novel ruthenium(II) bipyridine or terpyridine complexes bearing an increasing number of pyrene or toluyl moieties is described. The ruthenium complexes are constructed in a first step with ligands bearing the required bromine functions, followed in a second step by stepwise grafting of 1-ethynylpyrene or 4-ethynyltoluene promoted by Pd(0). A complex bearing a protected triethylsilylacetylene function was also prepared. In situ deprotection of this function with K₂CO₃ and cross-coupling with 1-bromopyrene afforded a soluble complex in which two pyrene moieties are linearly linked via ethynyl spacers to one of the bipyridine ligands. These highly coloured complexes exhibit well defined absorption and emission properties in solution at both rt and 77 K.     

二-2,2′:6′,2″-三联吡啶-4′-(4-苯甲酰)-乙二胺的合成

二、三联吡啶作为螯合配体可以和过渡金属离子生成高度稳定的配合物,并具有有趣的物理性质。因此在过去的几十年里,二、三联吡啶金属配合物受到广泛而深入的研究。文章在前人的研究基础上获得了含官能化双(三联吡啶)单元结构的二-2,2′:6′,2″-三联吡啶-4′-(4-苯甲酰)-乙二胺配体,可以作为非共价聚合物的很有效的构建模块,合成有趣的金属超分子聚合物。     

Color Bricks: Building Highly Organized and Strongly Absorbing Multicomponent Arrays of Terpyridyl Perylenes on Metal Oxide Surfaces

Terpyridine‐substituted perylenes containing cyclic anhydrides in the peri position were synthesized. The anhydride group served as an anchor for assembly of the terpyridyl‐crowned chromophores as monomolecular layers on metal oxide surfaces. Further coordination with Zn²⁺ ions allowed for layer‐by‐layer formation of supramolecular assemblies of perylene imides on the solid substrates. With properly selected anchor and linker molecules it was possible to build high quality structures of greater than ten successive layers by a simple and straightforward procedure. The prepared films were stable and had a broad spectral coverage and high absorbance. To demonstrate their potential use, the synthesized dyes were employed in solid‐state dye‐sensitized solar cells, and electron injection from the perylene antennas to titanium dioxide was observed.