Synthesis and properties of dithienometallole-pyridinochalcogenadiazole alternate polymers

Abstract

Donor-acceptor-type alternate polymers composed of dithienometallole (metal ¼ Si or Ge) and pyridinocalcogenadiazole (chalcogen ¼ S or Se) units with the molecular weights of M n ¼ 5700-7400 (M w /M n ¼ 1.3-1.7) were obtained as black solids by the Stille coupling reactions of the corresponding bis(trimethylstannyl)dithienometallole and dibromopyridinochalcogenadiazole. Ultraviolet-visible absorption spectra of the polymers showed highly red-shifted broad bands centered at 732-745 nm in chlorobenzene solutions. Bulk heterojunction-type polymer solar cells with blend films of the polymers and PC 70 BM as the active layers were fabricated, and a maximum power conversion efficiency of 3.46% was obtained using the dithienogermole-pyridinothiadiazole polymer.

Dye-sensitized solar cells: Investigation of D-A-π-A organic sensitizers based on [1,2,5]selenadiazolo[3,4-c]pyridine

“…Yield 573 mg (84%). IR and NMR spectra are similar to the literature data [9]. [1,2,5]chalcogenadiazolo [3,4-c]pyridines 1, 2 and arylboronic acids 3, 4…”

“…The novel [1,2,5]selenadiazolo [3,4-c]pyridine moiety has previously been used in low band gap polymers which exhibited highly red-shifted absorption maxima from those of the benzothiadiazole analogues [9,10]. In this work we therefore aimed to explore new organic dyes based on the [1,2,5]selenadiazolo [3,4-c]pyridine unit concept and to obtain π-conjugated condensed-polycyclic structures.…”

Marriage of heavy main group elements with π-conjugated materials for optoelectronic applications

“…4; 21-41). [57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72] The dithienogermole containing polymers are generally obtained by metal-catalyzed cross-coupling methodologies such as the Stille, Suzuki-Miyaura and Sonogashira reactions, and very high number average molecular weights (M n ) of up to 133000 g mol -1 have been occasionally reported. Due to d-block contraction, 73,74 the electronegativity of germanium is slightly closer to carbon than the related silicon species, 75 therefore reducing the polarization of the Ge-C bond and rendering aryl germanes more tolerable towards bases and nucleophiles than the related aryl silanes.…”

Synthesis and optical and photovoltaic properties of dithienosilole–dithienylpyridine and dithienosilole–pyridine alternate polymers and polymer–B(C6F5)3 complexes

“…The absorption maxima were blue-shifted from those reported for DTS homopolymers (pDTS, l max ¼ 533-561 nm), 22,23 DTS-bithiophene alternate polymers (pDTS2T, 544-558 nm) 22,23 and a DTS-pyridinothiadiazole alternate polymer (pDTSPTA, 732 nm) 20 (Scheme 4). The introduction of pyridine units into pDTS2T and pDTS appeared to hinder the planarity of the resulting p-conjugated systems due to steric repulsion between the C-H bonds of the adjacent thiophene and pyridine rings.…”

“…20 The ITO surface was cleaned further by exposure to ozone for 10 min, and a layer of PEDOT:PSS (poly(2,3-dihydrothieno-1,4-dioxin)-poly(styrenesulfonate)) with a thickness of 30 nm was spin-coated onto the cleaned ITO substrate immediately thereafter. The PEDOT:PSS-coated ITO substrate was heated at 150 1C for 10 min, onto which a solution of the polymer:PC 71 BM blend in o-dichlorobenzene containing diiodooctane (2.5 vol%) was spincoated after filtering through a 0.45-mm polytetrafluoroethylene syringe filter.…”