3141-27-3Relevant articles and documents
Synthesis of extended α,α'-oligo(silylthiophenes) by cerium(IV) oxidative coupling reactions
Mustafa, Ali H.,Shepherd, Michael K.
, p. 2743 - 2744 (1998)
Cerium(IV) oxidative dimerisations of 4,4'-bis(trimethylsilyl)-2,2':5',2''-terthiophene and the quaterthienyl analogue 1c gave the corresponding sexi- and octi-thiophenes; the latter have been used to prepare α-linked hexadecithiophene and tetracosithiophene derivatives.
The influence of an ethynyl spacer on the electronic properties in 2,5-ferrocenyl-substituted heterocycles Dedicated to Prof. Dr. Claude Lapinte for his outstanding contribution to organometallic chemistry especially to electron transfer studies.
Pfaff, Ulrike,Hildebrandt, Alexander,Korb, Marcus,Lang, Heinrich
, p. 2 - 9 (2015)
A series of binuclear complexes based on five-membered heterocycles featuring alkynyl ferrocenyl groups, 2,5-(FcCC)2-cC4H2E (E = NPh, 3a; S, 3b; O, 3c), has been synthesized using the Sonogashira C,C cross-coupling protocol. The molecular structures of 3a and 3c in the solid state are discussed. The influence of the ethynyl unit on the electronic and (spectro)electrochemical properties of these compounds is shown by cyclic voltammetry (CV), square wave voltammetry (SWV) and in situ UV-Vis-NIR and IR spectroscopy. The high ΔEp values (140-204 mV) of the single reversible redox events indicate that two individual oxidation processes take place in a close potential range. Nevertheless, the NIR measurements indicate weak and broad intervalence charge transfer (IVCT) absorptions for the mixed-valent monocationic species 3a-c+. Compared to 2,5-Fc2-cC4H2E (E = NPh, S, O) the absorptions for the IVCT transitions are shifted hypsochromically, showing that the charge transfer process is promoted at higher excitation energies, due to larger metal-metal distances in 3a-c. The occurrence of IVCT absorptions demonstrates that the 2,5-diethynylferrocenyl heterocycles are class II systems according to Robin and Day.
Electrochromic properties of pyrene conductive polymers modified by chemical polymerization
Chang, Lijing,Hou, Yanjun,Li, Rui,Ma, Yang,Miao, Shoulei,Wang, Cheng,Xu, Haoran,Zhang, Yuhang
, p. 39291 - 39305 (2021/12/27)
Pyrene is composed of four benzene rings and has a unique planar melting ring structure. Pyrene is the smallest condensed polycyclic aromatic hydrocarbon, and its unique structural properties have been extensively studied. Pyrene has excellent properties such as thermal stability, high fluorescence quantum efficiency and high carrier mobility. This paper mainly used thiophene, EDOT and triphenylamine groups to enhance the pyrene based π-conjugated system and control the molecular accumulation of organic semiconductors, and improve their charge transport performances. Five kinds of polymer were synthesized and correspondingly characterized. The five kinds of pyrene conductive polymer had outstanding properties in terms of solubility, fluorescence intensity and thermal stability, good film-forming properties, stable electrochromic properties and high coloring efficiency. The coloration efficiency (CE) of PPYTP was as high as 277 cm2C?1, and the switching response time was short. The coloring time of PPYEDOT was 1.3 s and the bleaching time was 3.2 s. The lower impedance will also provide the possibility of such polymers being incorporated into electrochromic devices in the future. In short, the synthesized new pyrene conductive polymers will have wide application prospects in the field of electrochromic materials.
Synthesis and characterization of poly(tetramethylsilarylenesiloxane) derivatives with oligothiophene based moiety
Nishizawa, Ibuki,Ajito, Hiroki,Gonmori, Yuzuki,Katoh, Ryuzi,Ichikawa, Tsukasa,Nemoto, Nobukatsu
, p. 93 - 101 (2019/02/15)
Poly(tetramethylsilarylenesiloxane) derivatives (P1T-P4T, P4TC) that contained thiophene (1T), oligothiophenes such as dithiophene (2T), terthiophene (3T), quaterthiophene (4T), or 2,6-di(2-thienyl)-4,4-diphenylcyclopentadithiophene (4TC) as the main chain components were synthesized via polycondensation reaction of the corresponding disilanol monomers (M1T-M4T, M4TC). The obtained polymers other than P4T that contained quaterthiophene units exhibited the good solubility in common organic solvents, such as toluene, chloroform, tetrahydrofuran and so on. The glass transition temperature (Tg) and melting temperature (Tm) of the obtained polymers regarding P1T-P4T were increased with the extension of the thiophene rings of the monomeric unit as deduced from the results of the differential scanning calorimetry (DSC). On the other hand, the Tm was not observed for P4TC that was composed of 2,6-di(2-thienyl)-4,4-diphenylcyclopentadithiophene units. P2T that was composed of dithiophene units exhibited the highest temperature at 5% weight loss (Td5) of 467 °C in all present polymers. The bathochromic and hyperchromic effects in the absorption spectra as well as the improvement of fluorescence quantum yield were observed by the introduction of dimethylsilyl group onto the present oligothiophene derivatives. These effects became unremarkable accompanying the elongation of the thiophene rings of the monomeric units; however, 4TC exhibited a more significant change by the introduction of the dimethylsilyl group than the other oligothiophenes derivatives, indicating that the introduction of the cardo-structure was effective in the improvement of the optical properties. M4TC and P4TC exhibited the fluorescence wavelength around 500 nm and the highest fluorescence quantum yield of the present series of poly(tetramethylsilarylenesiloxane) derivatives, i.e., 0.40, plausibly because the free rotation between thiophene rings in oligothiophene inhibited by the cardo-structures and the bulky diphenyl groups at 4-position of cyclopentadithiophene moiety suppressed the nonradiative transition.