A5026128903- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Synthesis and Properties of Aromatic Compounds
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Fullerene Chemistry and Applications
- Porphyrin and Phthalocyanine Chemistry
- Conducting polymers and applications
- Perovskite Materials and Applications
- Photochromic and Fluorescence Chemistry
- Molecular Junctions and Nanostructures
- Graphene research and applications
- Organic Light-Emitting Diodes Research
- Crystallography and molecular interactions
- Organic Chemistry Cycloaddition Reactions
- Advanced Memory and Neural Computing
- Polydiacetylene-based materials and applications
- Supramolecular Chemistry and Complexes
- Liquid Crystal Research Advancements
- Organic and Molecular Conductors Research
- Advanced Photocatalysis Techniques
- Covalent Organic Framework Applications
- Carbon Nanotubes in Composites
- Photochemistry and Electron Transfer Studies
- TiO2 Photocatalysis and Solar Cells
National University of Singapore
2016-2025
Zhejiang Sci-Tech University
2017-2018
Yonsei University
2013
Universidad de Málaga
2013
Institute of Materials Research and Engineering
2012-2013
King Abdullah University of Science and Technology
2010-2013
Max Planck Institute for Polymer Research
2004-2008
Max Planck Society
2005-2008
University of California, Santa Barbara
2007-2008
State Key Laboratory of Polymer Physics and Chemistry
2000-2001
Acenes represent a series of molecules with intriguing physical and chemical properties for applications in organic electronics. Nevertheless, the stability solubility issues associated longer acenes are two major obstacles their applications. In this Perspective, we summarize design principles stabilizing acenes. A variety stable acene based derivatives included discussion. Finally, highlight some research areas where breakthroughs will be critical further development materials.
Porphyrin-based dyes recently have become good candidates for dye-sensitized solar cells (DSCs). However, the bottleneck is how to further improve their light-harvesting ability. In this work, N-annulated perylene (NP) was used functionalize Zn-porphyrin, and four "push-pull"-type NP-substituted fused porphyrin with intense absorption in visible even near-infrared (NIR) region were synthesized. Co(II/III)-based DSC device characterizations revealed that WW-5 WW-6, which an ethynylene spacer...
Fast and highly efficient intramolecular singlet exciton fission in a pentacene dimer, consisting of two covalently attached, nearly orthogonal units is reported. Fission to triplet excitons from this ground state geometry occurs within 1 ps isolated molecules solution dispersed solid matrices. The process exhibits sensitivity environmental polarity competes with geometric relaxation the state, while subsequent decay strongly dependent on conformational freedom. near arrangement unlike any...
Clar's aromatic sextet rule has been widely used for the prediction of reactivity and stability polycyclic hydrocarbons with a closed-shell electronic configuration. Recent advances in open-shell biradicaloids have shown that number rings plays an important role determination their ground states. In order to test validity this singlet biradicaloids, two soluble stable dibenzoheptazethrene isomers DBHZ1 DBHZ2 were prepared by different synthetic approaches isolated crystalline form. These...
Abstract An efficient synthesis of 9,9‐bis(2‐ethylhexyl)fluorene oligomers up to the heptamer is reported, with repetitive Suzuki and Yamamoto coupling reactions employed in synthesis. The key steps for preparation essential intermediates include Pd‐catalyzed transformation aryl bromides boronic esters (Miyaura reaction) application much higher reactivity over cross‐coupling reaction diazonium salts. Variation UV/Vis absorption photoluminescence characteristics chain length reported....
p-Quinodimethane (p-QDM) is a fundamental building block for the design of π-conjugated systems with low band gap and open-shell biradical character. However, synthesis extended p-QDMs has usually suffered from their intrinsic high reactivity poor solubility. In this work, benzannulation together terminal cyano-substitution was demonstrated to be an efficient approach series soluble stable tetracyano-oligo(N-annulated perylene)quinodimethanes nPer-CN (n = 1-6), longest molecule having 12...
A slot-die coating technique is used for the crystal alignment of triisopropylsilylethynyl (TIPS)-pentacene in solution-processed field-effect transistors (FETs). The film thickness, uniformity, and growth behavior are well controlled by tuning parameters using a mixed solvent system (toluene/anisole). An average saturation regime FET mobility 1.8 cm2 V−1 s−1 achieved under ambient conditions. As service to our authors readers, this journal provides supporting information supplied authors....
Various strategies to chemically modify acenes for n-channel OFETs are discussed. Such could also be useful design of efficient n-type organic semiconductors based on other π-systems.
Incorporation of a non-hexagonal ring into nanographene framework can lead to new electronic properties. During the attempted synthesis naphthalene-bridged double [6]helicene and heptagon-containing by Scholl reaction, an unexpected azulene-embedded its triflyloxylated product were obtained, as confirmed X-ray crystallographic analysis 2D NMR spectroscopy. A 5/7/7/5 ring-fused substructure containing two formal azulene units is formed, but only one them shows azulene-like structure. The...
Abstract Synthesis of a carbon nanobelt (CNB) is very challenging task in organic chemistry. Herein, we report the successful synthesis an octabenzo[12]cyclacene based CNB ( 6 ), which can be regarded as sidewall fragment (12,0) nanotube. The key intermediate compound, tetraepoxy 5 was first synthesized by Diels–Alder reaction, and subsequent reductive aromatization gave fully conjugated . X‐ray crystallographic analysis unambiguously confirmed belt‐shaped structure 1 H NMR spectrum...
Abstract Non‐alternant, non‐benzenoid π‐conjugated polycyclic hydrocarbons (PHs) are expected to exhibit very different electronic properties from all‐benzenoid PHs. Reported herein the syntheses and physical of four derivatives two azulene‐fused s‐indacene isomers, diazuleno[2,1‐a:2′,1′‐g]‐s‐indacene (DAI‐1) diazuleno[2,1‐a:1′,2′‐h]‐s‐indacene (DAI‐2). The backbone both isomers contains 28π electrons is a 7‐5‐5‐6‐5‐5‐7 fused ring system. X‐ray crystallographic analysis, NMR spectra,...
We report the challenging synthesis of two very long bis(anthraoxa)quinodimethanes with nine (ABA) and ten (ANA) consecutively fused six-membered rings. The former is stable negligible diradical character, while latter a moderate character ( y0 = 25.0%) reactive an unexpected trifluoroacetic substituted product (ANA-TFA) was isolated. X-ray crystallographic analysis revealed planar backbone typical quinoidal for both. Their dications can be regarded as isoelectronic structures respective...
Non-alternant non-benzenoid π-conjugated polycyclic hydrocarbons (PHs) are expected to exhibit very different electronic properties from the all-benzenoid PHs. Herein, we report synthesis and physical of three azulene-fused acene molecules (1, 2 3), which isoelectronic pentacene, hexacene heptacene, respectively. X-ray crystallographic analysis, NMR spectra, theoretical calculations reveal a localised aromatic backbone comprising all six- five-membered rings while seven-membered ring remains...
A heptacene derivative 1 substituted with four electron-deficient trifluoromethylphenyl and two triisopropylsilylethynyl (TIPSE) groups was prepared by a new synthetic strategy. Photo-oxidative resistance studies showed that this newly developed compound persisted 47 h in solution under ambient light air conditions, it represents the most stable reported to date.
A new type of discotic mesogen based on triphenylene-fused triazatruxenes was prepared by microwave-assisted 6-fold Suzuki coupling reactions from hexabromotriazatruxene, followed FeCl3-mediated oxidative cyclodehydrogenation. These disklike molecules showed extended π-conjugation, compared with the triphenylene and triazatruxene themselves. More importantly, they possess desirable HOMO energy levels, which allow efficient charge injection electrodes such as gold electrodes. Their thermal...
A series of star-shaped octupolar triazatruxenes (TATs, 1−6) with intramolecular "push−pull" structure were synthesized and their photophysical properties have been systematically investigated. These chromophores showed obvious solvatochromic effect, i.e., significant bathochromic shift the emission spectra larger Stokes shifts observed in more polar solvents mainly due to photoinduced charge transfer (ICT). The two-photon absorption (2PA) cross-section values determined by excited...
Cationic conjugated polyelectrolytes poly110 and poly120 were designed, synthesized, characterized with the anticipation of function in determination double-stranded DNA concentration [dsDNA]. Their structures contain a π-delocalized optically active backbone composed phenylene−fluorene segments copolymerized 2,1,3-benzothiadiazole (BT) units charged pendant groups that allow excellent solubility water. The subscript poly1x refers to molar percent BT chain. Addition dsDNA or results change...
Biradicaloids based on quinoidal rylenes! Soluble and stable tetracyanoquaterrylenequinodimethane (QR-CN) tetracyanohexarylenequinodimethane (HR-CN) were synthesized. QR-CN has a closed-shell structure in the ground state, whereas HR-CN singlet biradical state. Both compounds showed very strong one-photon two-photon absorption NIR range.
Stepwise cyanation of tetrabromonaphthalenediimide (NDI) 1 gave a series cyanated NDIs 2-5 with the monocyanated NDI 2 and dicyanated 3 isolated. The tri- tetracyano- 4 5 show intrinsic instability toward moisture because their extremely low-lying LUMO energy levels. partially intermediates can be utilized as air-stable n-type semiconductors OFET electron mobility up to 0.05 cm(2) V(-1) s(-1).
A facile route has been developed for the preparation of a new family contorted 1.2,3.4,7.8,9.10-tetrabenzocoronenes (TBCs). two-step cyclization reaction, i.e., oxidative photocyclization followed by FeCl3-mediated intramolecular cyclodehydrogenation, was carried out on olefin precursors to obtain final TBC compounds. These molecules have conformation due steric overcrowding as disclosed single-crystal crystallographic analysis. Nevertheless, they showed extended π-conjugation compared with...
Bisindeno-annulated pentacenes 3a and 3b were synthesized by a simple regio-selective, FeCl3-mediated Scholl reaction from the corresponding 6,13-diaryl pentacene precursors. The fusion of two indeno-units dramatically changes electronic properties chemical reactivity obtained compounds exhibited exceptionally high photo-stability in solution, with half-life time 11.2 (3a) 32.0 (3b) days under ambient light air conditions. Ordered molecular packing small π-π stacking distance was observed...