Platinum acetylide polymers

Scheme 6. Syntheses of hyper-branched platinum-acetylide polymers 20 and 21...

The use of Pt-acetylides containing phosphine ligands was extended further by the Schanze group in 2006 [84, 85], In one contribution, they incorporated platinum-acetylide polymers into photovoltaic devices which demonstrate good device efficiency. Transient absorption studies provide definitive evidence for photoinduced electron transfer from the Pt-acetylide to PCBM by the temporal evolution of the TA spectrum, observing the formation of the PCBM radical anion at 1,050 nm. The same system was eventually demonstrated to operate as a bulk heterojunction photovoltaic device [84],... 

There are several reports on the exploitation of ferrocenyl moiety in the building up of polymetallaynes. A novel heterobimetallic platinum acetylide polymer of ferrocenylfluorene, P72, was reported and spectroscopically characterized.95 The presence of significant donor-acceptor interaction leads to a narrow band-gap value of 2.1 eV for this Pt-Fe mixed material, which is much lower than for the parent polymer, P25. The polymer is electroactive, with the half-wave potential of the ferrocene moiety slightly more anodic in P72 than in the diethynyl ligand precursor, which is in line with the transfer of electron density from the ferrocenyl donor unit to the electron-accepting Pt(II) center through the acetylide linkage. 

Wang Q, He Z, Wild A, Wu H, Cao Y, Schubert US, Chui C-H, Wong W-Y (2011) Platinum-acetylide polymers with higher dimensionality for organic solar cells. Chem Asian 6 1766-1777... 

In the acetylide polymers of square planar nickel, palladium, and platinum listed in Table X, the imaginary part of the nonlinearity is the major contributor, implying significant two-photon absorption. Some of the poly-... 

Polymers and oligomers that are platinum-acetylide based have important optical and optoelectronic applications because the lowest triplet excited state involves a mixture of Ptn (dji) orbitals and organic n-conjugated orbitals that enhance the phosphorescence efficiency. Batista and Martin studied the low-lying... 

The synthesis of several high molecular-weight platinum polyyne polymers carrying chiral (R)-l,l -bi-2-naphthol bridge, P17, was described.48 These represent the first examples of metal acetylide polymer with an optically active backbone. They display much larger specific negative optical rotations than both the metal-free alkyne precursors and their corresponding dinuclear model compounds. These results support the fact that the main chain of P17 adopts a one-handed helical conformation and induces the helical chirality of the polymers. 

Most polymetallaynes have band gaps of ca. 2.4-3.2 eV but the value can be reduced substantially to ca. 1.7 eV by the use of alternating donor (bis(phosphine)platinum acetylide) and acceptor (electron-deficient thienopyrazine) units in the backbone as in polymer 191." Similarly, donor-acceptor interactions appear to be important in polymer 192, which possesses a ferrocenylfluorenyl spacer that has a band gap of 2.1 eV. In the absence of the donor metallocene group, the analogous polymer has a substantially wider gap ( g = 2.9... 

Different types of metallodendrimers with metal compounds at each repeating unit throughout the dendrimer have been reviewed [195,197]. Because of their high concentration of metal centers, they can be considered as nanoparticle equivalents. One example is the platinum acetylide dendrimer 72 obtained by a stoichiometric transmetallation to form acetylides [204]. This metallodendrimer has a precedent in earlier syntheses of linear Pt-acetylide coordination polymers. Several papers describe the synthesis of various Ru pyridyl complexes as repeating units for photochemical investigations and non-... 

We have widened our scope in the current work to form a new series of platinum aryl-acetylide polymers and their dinuclear counterparts containing 0, S, SO, and SOj functional groups. These are remarkable model systems that can be used to evaluate how chalcogen-based conjugation-interrupters would limit the effective conjugation length of polymetallaynes. 

Ikeda, M., Tanabe, Y, Hasegawa, T. et al. (2006) Construction of double-stranded metaUo-supramolecular polymers with a controlled helicity by combination of salt bridges and metal coordination. Journal of the American Chemical Society, 128,6806-6807 Furusho, Y., Tanabe, Y. and Yashima, E. (2006) Double helix-to-double helix transformation, using platinum(II) acetylide complexes as surrogate linkers. Organic Letters, 8, 2583-2586 Furusho, Y. and Yashima, E. (2007) Molecular design and synthesis of artificial double helices. Chemical Record, 7, 1-11. 

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