302554-80-9Relevant articles and documents
Bipolar π-conjugation interrupted host polymers by metal-free superacid-catalyzed polymerization for single-layer electrophosphorescent diodes
Chen, Bing,Xiao, Zhanhai,Li, Yanhu,Yu, Lei,Yang, Wei,Feng, Jiwen
, p. 50027 - 50034 (2014)
Novel aromatic bipolar host polymers (P1 and P2) containing pyridine as an electron transporting unit and carbazole and fluorene as hole transporting units in the π-conjugation interrupted polymer backbone have been synthesized by a metal-free superacid-catalyzed polyhydroxyalkylation. The present polymers show good thermal stability, with high glass transition temperatures and decomposition temperatures. The conjugation lengths of the polymers are effectively confined into the repeating units due to the δ-C bond interrupted polymer backbone, giving rise to quite high triplet energy (2.79 eV for P1) and a wide band gap of around 3.33 eV, which make them promising hosts for phosphorescent OLEDs. The results suggest that the strategy of incorporating bipolar blocks into the π-conjugation interrupted polymer backbone can be a promising approach to obtain host polymers with high triplet level for green and even blue phosphorescent polymer light-emitting diodes on a simple device structure and using a solution-processed technique.
Designed Synthesis and Crystallization of Isomorphic Molecular Gyroscopes with Cell-like Bilayer Self-Assemblies
Ochoa, Ma. Eugenia,Labra-Vázquez, Pablo,Farfán, Norberto,Santillan, Rosa
, p. 2795 - 2803 (2018)
Two molecular rotors featuring pyridine and fluorobenzene rings as polar rotators and 9-octylfluorenyl stators were synthesized. Their crystal structures were established through SXRD techniques, crystallizing in the monoclinic chiral P21 space group. The supramolecular assemblies of both isomorphs showed an orientation of static dipoles through the crystal lattice and the formation of intriguing 2D layers that resemble cell membranes, a typical example of an amphidynamic system. Small activation energies and the modulation of the first-order hyperpolarizabilities of these compounds as a function of rotational dynamics were revealed through DFT computations at the CAM-B3LYP/M06-2X/cc-pVDZ level of theory and correlated with a potential use of these materials as photonic switches.
Design and synthesis of solution processable green fluorescent D-π-A dyads for OLED applications
Thurakkal, Shameel,Sanju, Krishnankutty S.,Soman, Anjaly,Unni, K. N. Narayanan,Joseph, Joshy,Ramaiah, Danaboyina
, p. 5456 - 5464 (2018/04/02)
New solution processable organic donor-π-acceptor dyads 1 and 2 having electron donating phenoxazine and electron accepting oxadiazole groups have been synthesized. Intramolecular electron communication between the donor and acceptor moieties of these dyads was tuned through changing the substitution pattern at the phenylene linker. The photophysical properties of these dyads have been studied in the solution and film states. These dyads showed green fluorescence and exhibited a positive solvatochromism in the emission spectra, which indicates more polar excited states owing to an efficient charge migration from the donor phenoxazine to the acceptor oxadiazole moiety. The electrochemical, morphological and thermal properties were investigated through cyclic voltammetry, thermogravimetric and atomic force microscopy (AFM) analyses. To understand the electronic structure and band gap of these dyads, density functional theory (DFT) calculations have been performed. Furthermore, we have fabricated the solution processed un-doped electroluminescence devices based on these dyads, which exhibited efficient green emission with Commission Internationale de l'Eclairage (CIE) coordinates of (0.26, 0.49) and (0.27, 0.47) for 1 and 2, respectively, with a luminance maximum of ca. 1751 cd m-2 for the dyad 1, thereby demonstrating its use in organic light emitting diodes (OLEDS).
Design and synthesis of N-substituted perylene diimide based low band gap polymers for organic solar cell applications
Meena, Savita,Mohammad, Tauheed,Dutta, Viresh,Jacob, Josemon
, p. 30468 - 30480 (2018/09/11)
In this study, we report on the synthesis and device studies of a series of new copolymers containing N-substituted perylene dimide and dioctylfluorene units as part of the main backbone. A facile synthetic approach avoiding non-selective bromination was used to synthesize the monomer M1 by the reaction of perylene-3,4,9,10-tetracarboxylic dianhydride with 2-amino-7-bromo-9,9-dioctylfluorene. The copolymers P1 and P2 were synthesized by Suzuki polycondensation of M1 with 2,2′-(9,9-dioctyl-9H-fluoren-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) M2 and 9-(heptadecan-9-yl)-2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole M3, respectively. The copolymer P3 was synthesized by direct arylation polymerization of M1 with 4,7-bis(4-octylthiophen-2-yl)benzo[c]-1,2,5-thiadiazole M4. All the copolymers showed thermal stability greater than 380 °C as evidenced from thermogravimetric analysis. The copolymers exhibited a narrow optical band gap (1.80-2.08 eV) with their UV-visible absorption spectra extending up to the NIR region and they are found to be suitable for use in OSC applications. The molecular weights of the polymers P1-P3 were found to be in the range of 10.68 to 16.02 kg mol-1 as measured from GPC analysis. The surface morphology of the active layers based on P1/P2/P3:P3HT blend films was investigated by AFM and the rms values from height images range from 0.65 to 2.90 nm. The polymers were blended with P3HT to fabricate BHJ solar cells in three different weight ratios i.e. 1 : 1, 1.5 : 1 and 2 : 1 and the best power conversion efficiency was observed for the binary film of P3:P3HT blend device in a 1 : 1 weight ratio which reached up to 1.96% with a Voc of 0.55 V, Jsc of 10.12 mA cm-2 and FF of 34.63% which is among the highest reported for BHJ solar cells with N-substituted PDI based acceptors.
