Terpyridine ruthenium

Despite the extensive application of ruthenium complexes in DSSC, transition metal containing polymers have received relatively little attention in the fabrication of polymeric photovoltaic cells. Most of the early works on ruthenium containing polymers were focused on the light-emitting properties.58-60 Several examples of ruthenium terpyridine/bipyridine containing conjugated polymers and their photoconducting/electroluminescent properties were reported.61,62... 

All these polymers with ruthenium terpyridine/bipyridine complexes contain ionic ruthenium complex on the polymer main chain. Other than the... 

Finally, conjugated materials 40 based on poly(phenylene thiophene) and poly (fluorene thiophene) main chain polymers functionalized with pendant trithiocyanato ruthenium terpyridine complexes were synthesized by the Suzuki coupling reaction. Heterojunction photovoltaic cells with the simple structure ITO/polymer/C-60/Al were fabricated. Under simulated AM1.5 solar light illumination, the short circuit currents, open circuit voltages, and power conversion efficiencies of the photovoltaic cells were measured to be 1.53-2.58 mAcm 2, 0.12-0.24 V, and 0.084-0.12%, respectively [77]. 

Figure 6 Various supramolecular cross-linking strategies based on (a) the three-point CA-triazine couple and the six-point CA-isophthalamide (Hamilton wedge) couple (b) ruthenium-terpyridine coordination complexes (c) and (d) the platinum- or palladium-based pincer complexes. ...

The oxidation of both aliphatic and aromatic amines to nitriles by O2 or air in the presence of the Ru2Cl4(az-tpy)2 complex indicates that the conversion is strongly influenced by the alkyl chain length. The amines with shorter chain had lower conversions than those with longer chains. Further, the ruthenium terpyridine complex functionalized with azulenyl moiety at the 4-position of the central pyridine core provided a much higher catalytic reactivity compared with a series of ruthenium terpyridine complexes. The use of deuterated benzylamine demonstrated the importance of RuOH in the mechanism of the reaction." ... 

Vectorial transfer of electronic energy in rod-like ruthenium-osmium complexes with bis-2,2, 2"-terpyridine ligands 97CC333. 

Constable, E.C., Henney, R.P.G., Leese, T.A. and Tocher, D.A. (1990) Cyclometallation reactions of 6-phenyl-2,2 -bipyridine a potential C,N,N-donor analogue of 2,2 6, 2"-terpyridine. Crystal and molecular structure of dichlorobis (6-phenyl-2,2 -bipyridine)ruthenium(II). Journal of the Chemical Society, Dalton Transactions, (2), 443. 

Recently, Newkome et al. [165] described the synthesis of dendritic lock and key complexes, such as 78, which is based on the well-researched bzsterpyridine-ruthenium (—(Ru)—) coordination chemistry (Fig. 33). Dendritic terpyridines of the first and second generation were reacted with RuC13 and this formed the... 

For instance, some time ago Newkome et al. reported the synthesis of ruthenium based dendrimers [170]. A dendrimer (80) with twelve peripheral terpyridine ligands was built around a central quaternary carbon-based core. In the final step complexation between the terminal ligand of the dendrimer and a terpyridinyl ruthenium chloride building block afforded the dodecaruthenium cascade molecule 80 (Fig. 35). Thus, preconstructed cores and dendritic fragments were linked by Ru2+ as the connecting unit and this mode of connectivity could be denoted by [—(Ru)—]. 

As a continued effort to prepared hexameric systems based on the self-assembly of directed bw-terpyridine monomers, several interesting in families, e.g. 43, of iron and ruthenium connectivity have appeared <06DMP413, 06DT3518>. But in the assembly process, the creation of a three-step procedure to the novel first nondendritic fractal 44 entitled the "Sierpinski hexagonal gasket" was reported <06MI1782>. 

Terpyridine moieties have been introduced as a terminal unit of macromolecules. In a subsequent procedure the two-step self-assembly process based on Rum/Run chemistry was used for polymers end-capped with the 2,2/ 6/,2 -terpyridine ligand. More precisely, the terpyridine-functionalized polymers were complexed with RUCI3 to selectively form a mono-complex. In a further step, this mono-complex was reacted under reducing conditions with other uncomplexed 2,2/ 6/,2/-terpyridine-terminated polymer blocks in order to form an asymmetrical AB ruthenium(II) frzs-complex. 

A complete description of the synthetic methodology and the characterization of the obtained metallosupramolecular block copolymers was reported in a recent paper [324]. These compounds have been referred to as metallosupramolecular block copolymers and designated by the acronym Ax-[Ru]-By, where A and B are the two different polymer blocks, -[Ru]- denotes the fczs-2,2/ 6/,2/terpyridine-ruthenium(II) linkage between the A and B blocks, and x and y represent the average degree of polymerization of the A and B blocks, respectively. The chemical structure of a PEB-[Ru]-PEO metallosupramolecular copolymer is depicted in Fig. 23. 

In a very recent set of papers [48,54,59,60,131,132,324-328], the synthesis and characterization of metallosupramolecular amphiphilic block copolymers containing a hydrophilic PEO block linked to a hydrophobic PS or PEB block through a fozs-2,2/ 6/,2/terpyridine-ruthenium(II) complex have been described. These copolymers form the so-called metallosupramolecular micelles . 

The fozs-2,2/ 6/,2/terpyridine-ruthenium(II) complexes are assumed to be located at the core/corona interface, as schematically depicted in Fig. 23. 

Clustering in PS-[Ru]-PEO micelles was shown to be sensitive to temperature and ionic strength, as previously observed for covalent PS-PEO copolymer [131]. These effects were, however, more pronounced in the case of the metallosupramolecular copolymers, indicating a possible influence of the charged fois-2,2/ 6/,2/terpyridine-ruthenium(II) complexes [329]. 

Metal ions within organometallic dendrimers can be incorporated at the core, in the branches, or at branch points. Examples of dendrimers having metal-ion-containing cores included the dendritic metalloporphyrins [66,67] and related materials reported by Aida and Enomoto [68],Diederich et al. [69], Moore et al. [70], and Erechet et al. [71], dendritic terpyridine-ruthenium complexes report-... 

Pyridine-based ligands which have been used for dendrimers are 2,2-bipyridine (bpy) 17,2,3-bis(2-pyridyl)pyrazine (2,3-dpp) 18 and its monomethylated salt 19, and 2,2 6, 2"-terpyridine 20. Their transition metal complexes possessing dendritic structures were first reported in the collaborative work of Denti, Campagne, and Balzani whose divergent synthetic strategy has led to systems containing 22 ruthenium centers. - The core unit is [Ru(2,3-dpp)3] 21 which contains three... 

Newkome et al. also prepared a series of ruthenium bis-terpyridine core dendri-mers of the form Core1i-Rpt6(Newkome)-Periph9 98 In this series of molecules, the two dendrons could be of different generations. They found, as expected, that the redox center became more difficult to oxidize as the total number of generations around the core increased. Thus, for the molecule in which both the dendrons... 

Dendrimers are large molecules, and their solubility is often an issue. Thus, it is not surprising that dendrimers can be good candidates to precipitate upon and thus modify the surface of an electrode. Dendrimers with ferrocenyl peripheral units were shown to display well-defined redox waves with the ferrocenyl units oxidizing independently.176-178 These molecules oxidatively precipitated onto the electrode surface and were characterized electrochemically and by atomic force microscopy.44 It was later shown that cyclodextrin complexation increased the solubility of these molecules.179 Similar results were obtained with dendrimers containing pendant ruthenium tris (bipyridine) and bis(terpyridine) groups.180... 

Fluorescent redox switches based on compounds with electron acceptors and fluorophores have been also reported. For instance, by making use of the quinone/ hydroquinone redox couple a redox-responsive fluorescence switch can be established with molecule 19 containing a ruthenium tris(bpy) (bpy = 2,2 -bipyridine) complex.29 Within molecule 19, the excited state of the ruthenium center, that is, the triplet metal-to-ligand charge transfer (MLCT) state, is effectively quenched by electron transfer to the quinone group. When the quinone is reduced to the hydroquinone either chemically or electrochemically, luminescence is emitted from the ruthenium center in molecule 19. Similarly, molecule 20, a ruthenium (II) complex withhydroquinone-functionalized 2,2 6, 2"-terpyridine (tpy) and (4 -phenylethynyl-2,2 6, 2"- terpyridine) as ligands, also works as a redox fluorescence switch.30... 

Figure 10.8 shows the example ofa ruthenium(ii) bis-terpyridine complex that acts as the scaffold for a biscarboxylate recognition site 22 [62]. 

TRICHLORO[2,2 6, 2"-TERPYRIDINE]RUTHENIUM(III) AND PHOSPHINE LIGAND DERIVATIVES... 

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