Heptacyclic aromatic hydrocarbon isomers with two azulene units fused.

Azulene, known for its unique electronic properties and structural asymmetry, serves as a promising building block for the design of novel non-benzenoid polycyclic aromatic hydrocarbons (PAHs). Herein, we present the synthesis, characterization, and physical properties of three diazulene-fused heptacyclic aromatic hydrocarbons, 8,17-dioctyldiazuleno[2,1-:2',1'-]anthracene ( configuration), 16,18-dioctyldiazuleno[2,1-:1',2'-]anthracene ( configuration) and 3,18-dioctyldiazuleno[2,1-:1',2'-]phenanthrene ( configuration). Three compounds are configurational isomers with different fusing patterns of aromatic rings.

Mechanisms of acid generation from ionic photoacid generators for extreme ultraviolet and electron beam lithography.

Photoacid generators (PAGs) are important components of chemically amplified resists. The properties of PAGs directly affect the sensitivity of photoresists, line edge roughness, and resolution. Understanding the photoacid generation process in extreme ultraviolet (EUV) and electron beam (EB) lithography is helpful for photoresist design.

Property Prediction and Structural Feature Extraction of Polyimide Materials Based on Machine Learning.

The construction of material prediction models using machine learning algorithms can aid in the polyimide structural design and screening of materials as well as accelerate the development of new materials. There is a lack of research on predicting the optical properties of polyimide materials and the interpretation of the structural features. Here, we collected 652 polyimide molecular structures and used seven popular machine learning algorithms to predict the glass transition temperature and cut-off wavelength of polyimide materials and extract key feature information of repeating unit structures.

Azulene-Based π-Functional Materials: Design, Synthesis, and Applications.

ConspectusAzulene, an isomer of naphthalene, is a molecule of historical interest for its unusual photophysical properties, including a beautiful blue color derived from the narrow HOMO-LUMO energy gap and anti-Kasha fluorescence from S to S. More recently, it has attracted increasing attention for its novel electronic structure, including an electron-rich five-membered ring and an electron-deficient seven-membered ring with a dipole moment of 1.08 D resulting from resonance delocalization, its different reactivities at odd and even positions, and its stimuli-responsive behavior.

Azulene-Pyridine-Fused Heteroaromatics.

Azulene, a nonbenzenoid bicyclic aromatic hydrocarbon with unique electronic structure, is a promising building block for constructing nonbenzenoid π-conjugated systems. However, azulene-fused (hetero)aromatics remain rare as a result of limited synthetic methods. We report herein the unexpected synthesis of azulene- and pyridine-fused heteroaromatics , a seven fused ring system with 30π electrons, by reductive cyclization of a 1-nitroazulene.

Incorporation of 1,3-Free-2,6-Connected Azulene Units into the Backbone of Conjugated Polymers: Improving Proton Responsiveness and Electrical Conductivity.

Azulene as a potential building block for constructing organic/polymeric conjugated materials has attracted more and more attention due to its unique chemical structure and physicochemical properties. However, up to now, most reported azulene-based conjugated polymers have been dominated by the connection of the five-membered ring of azulene through 1,3-positions. Herein, by incorporating 1,3-free-2,6-connected azulene units into the polymeric backbone, two azulene-based all-carbon conjugated polymers and with different connection ways of 2,6-azulene and 2,7-fluorene units were presented.

Azulene-Based BN-Heteroaromatics.

Azulene, a nonalternant bicyclic aromatic hydrocarbon, has unique chemical and physical properties and is considered to be a promising building block for constructing novel polycyclic aromatic hydrocarbons (PAHs) and heteroaromatics. We present here the first two azulene-based BN-heteroaromatics and . The chemical structures and optical and electrochemical properties of both compounds have been investigated, as well as their sensing behavior in response to fluoride ion.

From Homochiral Assembly to Heterochiral Assembly: A Leap in Charge Transport Properties of Binaphthol-Based Axially Chiral Materials.

Chirality, as a fundamental symmetry property, plays an important role in molecular assembly in the solid state, impacting upon the properties and performance of organic materials. Here, heterochiral assembly was observed upon a binaphthol-based axially chiral material in the thin film state, where the heterochiral assemblies of racemic mixtures exhibit superior crystallization behavior and film morphologies than their homochiral counterparts. Additionally, a dramatic increase (nearly 2 orders of magnitudes) in electronic mobility was obtained upon switching the active layers of organic thin-film transistors from homochiral assemblies to heterochiral assemblies.

An Abnormal 3.7 Volt O3-Type Sodium-Ion Battery Cathode.

Layered O3-type sodium oxides (NaMO , M=transition metal) commonly exhibit an O3-P3 phase transition, which occurs at a low redox voltage of about 3 V (vs. Na /Na) during sodium extraction and insertion, with the result that almost 50 % of their total capacity lies at this low voltage region, and they possess insufficient energy density as cathode materials for sodium-ion batteries (NIBs). Therefore, development of high-voltage O3-type cathodes remains challenging because it is difficult to raise the phase-transition voltage by reasonable structure modulation.

Incorporation of 2,6-Connected Azulene Units into the Backbone of Conjugated Polymers: Towards High-Performance Organic Optoelectronic Materials.

Azulene is a promising candidate for constructing optoelectronic materials. An effective strategy is presented to obtain high-performance conjugated polymers by incorporating 2,6-connected azulene units into the polymeric backbone, and two conjugated copolymers P(TBAzDI-TPD) and P(TBAzDI-TFB) were designed and synthesized based on this strategy. They are the first two examples for 2,6-connected azulene-based conjugated polymers and exhibit unipolar n-type transistor performance with an electron mobility of up to 0.

Application of Azulene in Constructing Organic Optoelectronic Materials: New Tricks for an Old Dog.

Azulene, as an isomer of naphthalene, has received increasing interest due to its unique chemical structure and unusual photophysical properties, including a large dipole moment of 1.08 D, a narrow energy gap between the HOMO and LUMO, and abnormal fluorescence (anti-Kasha's rule) from the second excited state to the ground state. In this Minireview, the general strategies and representative synthetic methods for the preparation and functionalization of azulene and its derivatives are presented, and then the application of azulene-based optoelectronic materials in organic field-effect transistors and solar cells is discussed.

Biazulene diimides: a new building block for organic electronic materials.

Azulene, a 10-π-electron isomer of naphthalene, is a nonbenzenoid bicyclic aromatic hydrocarbon with a beautiful blue color and a large dipole moment. We present here the first class of azulene-based aromatic diimides, 2,2'-biazulene-1,1',3,3'-tetracarboxylic diimides (BAzDIs), which comprise a 2,2'-biazulene moiety and two seven-membered imide groups. DFT calculations, thermal, optical and electrochemical properties of two BAzDI derivatives as well as single crystal analysis and the charge transport behavior were studied.