- Heptazine: an Electron-Deficient Fluorescent Core for Discotic Liquid Crystals
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Herein, room-temperature discotic liquid crystals based on heptazine, an electron deficient central core, are reported for the first time. Mesomorphic behaviors of the materials are also investigated. Supramolecular assembly of the mesophase derivatives were confirmed by X-ray scattering experiments. Heptazine-based solid thin films are strong blue light emitters, whereas in the solution state, they are weakly emissive or non-emissive. The band gap energy is found to be low in this class of compounds. Formation of room-temperature mesophases, low band-gap behavior, and strong blue-light emission in the solid state are promising attributes for optoelectronic applications of the materials.
- Bala, Indu,Singh, Harpreet,Battula, Venugopala Rao,Gupta, Santosh Prasad,De, Joydip,Kumar, Sunil,Kailasam, Kamalakannan,Pal, Santanu Kumar
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- Synthesis and Structure of 2,5,8-Triazido-s-Heptazine: An Energetic and Luminescent Precursor to Nitrogen-Rich Carbon Nitrides
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Derivatized s-triazine (C3N3) precursors have seen significant recent use in the production of carbon nitride materials. Larger polycyclic molecular precursors, such as those containing an s-heptazine core (C6N7 or tri-s-triazine), may improve stability and order in carbon nitride products. In this Communication, we describe the synthesis and crystal structure of 2,5,8-triazido-s-heptazine (2). Synthesis of 2 was achieved from melon, an oligomeric s-heptazine synthesized by the pyrolysis of NH4SCN. Melon was converted to molecular 2,5,8-trichloro-s-heptazine, which was then transformed to the triazide upon reaction with (CH3)3SiN3. The crystal structure of 2 verifies that the s-heptazine is planar and the azides adopt a pinwheel-like C3h arrangement around the periphery. The s-heptazine core shows π delocalization in the C-N bonds around the periphery (av. 1.33 ), while the internal planar C-N bonds are longer (1.40 ). The heptazine units pack into parallel, but offset, layered sheets in the crystal. The triazide 2 exhibits photoluminescence at 430 nm and rapidly and exothermically decomposes upon heating at 185 °C to produce a tan thermally stable carbon nitride powder with a formula near C3N4. Copyright
- Miller, Dale R.,Swenson, Dale C.,Gillan, Edward G.
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- Tri-s-triazine derivatives. Part I. From trichloro-tri-s-triazine to graphitic C3N4 structures
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The first detailed structural characterisation of a functionalised tri-s-triazine derivative, trichloro-tri-s-triazine, is reported, which is a promising starting material for numerous compounds including graphitic C3N4 phases. DFT calculations show that a C3N4 structure based on tri-s-triazine should exist and that it is ~30 kJ mol-1 more stable than the previously reported C3N4 phase of lowest energy.
- Kroke, Edwin,Schwarz, Marcus,Horath-Bordon, Elisabeth,Kroll, Peter,Noll, Bruce,Norman, Arlan D.
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- Metal-Organic Nanocapsules with Functionalized s-Heptazine Ligands
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A metalloorganic capsule was synthesized where the ligand is a derivative of heptazine with three carboxylic groups that are coordinated to CuII cations, forming paddle-wheel motifs. Each nanocapsule is neutral, with 12 CuII centers and 8 ligands adopting a rhombicuboctahedron shape. It has almost 3 nm diameter, and the main intermolecular interactions in the solid are π··· πstacking between the C6N7 heptazine moieties. The nanocapsules can form monolayers deposited on graphite as observed by atomic force microscopy, which confirms their stability in solution.
- Maxwell, Lindley,Martínez, Héctor,Martín-Rodríguez, Alejandro,Gómez-Coca, Silvia,Rissanen, Kari,Ruiz, Eliseo
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- An N-rich metal-organic framework with an rht topology: High CO2 and C2 hydrocarbons uptake and selective capture from CH4
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We report the storage capacities and separation selectivity of an rht-type s-heptazine-based metal organic framework (MOF), [Cu3(TDPAH)(H 2O)3]·13H2O·8DMA, 1, (where TDPAH is 2,5,8-tris(3,5-dicarboxylphenylamino
- Liu, Kang,Li, Baiyan,Li, Yi,Li, Xu,Yang, Fen,Zeng, Guang,Peng, Yu,Zhang, Zhijuan,Li, Guanghua,Shi, Zhan,Feng, Shouhua,Song, Datong
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- Synthesis of some heptazine derivatives
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[Figure not available: see fulltext.] New derivatives of heptazine were prepared from 2,5,8-trichloroheptazine by a Friedel–Crafts reaction and Pd-catalyzed amination. New triamino-substituted heptazine derivative represents a soluble carbon nitride monomeric unit suitable for the assembly of metal–organic and covalent–organic frameworks. Aromatic substituents in heptazine ring can be displaced by an alkylamine in a pseudo-nucleophilic substitution reaction.
- Krūkle-Bērzi?a, Kristīne,Bērzi??, Kārlis,Shubin, Kirill
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- Hydrazone-Linked Heptazine Polymeric Carbon Nitrides for Synergistic Visible-Light-Driven Catalysis
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Heptazine-based conjugated polymeric carbon nitrides (PCNs) are promising metal-free photocatalysts, yet their synthesis is challenging due to the electron-deficiency and insolubility of heptazine units. Indeed, heptazine-containing polymers have only been prepared through nucleophilic substitution with amines by using toxic cyameluric chloride as the starting material. Herein, we report the novel and environmentally friendly method for preparing heptazine-based mesoporous PCNs with hydrazone links formed through a simple Schiff base condensation of melem-NH2 and aldehydes. Unlike cyameluric chloride, melem-NH2 is non-toxic, stable, and can be readily obtained from melem and hydrazine in solution. We demonstrate that the hydrazone linkages and the heptazine units synergistically enhance the photocatalytic activity of PCNs in visible-light-driven aerobic oxidation of benzyl alcohol to benzaldehyde. In particular, the polymer constructed from melem-NH2 and p-phthalaldehyde shows 17 times more activity than graphitic carbon nitride (g-C3N4).
- Zhang, Wei,Xu, Congying,Kobayashi, Takeshi,Zhong, Yun,Guo, Zhiyong,Zhan, Hongbing,Pruski, Marek,Huang, Wenyu
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- Integrating active C3N4moieties in hydrogen-bonded organic frameworks for efficient photocatalysis
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Hydrogen-bonded organic frameworks (HOFs) provide a platform to self-assemble numerous functional species into an ordered structure. Herein, a well-known photoactive C3N4moiety was integrated into an HOF structure (PFC-42) with the merits of high porosity and crystallinity. Under visible-light irradiation, the Pt nanoparticle-loaded PFC-42 (PFC-42-Pt) continuously produces hydrogen from water in the presence of scavengers with the evolution rate of 11.32 mmol g?1, which is outstanding among all the reported Pt/porous composite materials. The significantly high H2evolution of PFC-42-Pt compared with that of amorphous analogue bulk C3N4-Pt and nanosheet C3N4-Pt demonstrates that the ordered arrangement of photosensitizers dramatically improves the photocatalytic activity of the material, which is further proved by the recrystallization experiment. This study represents the first example of HOF capable of photocatalysis, not only demonstrating the great application potentials of HOF in heterogeneous photocatalysis but also rendering an excellent opportunity to reveal structure-activity relations.
- Li, Tao,Liu, Bai-Tong,Fang, Zhi-Bin,Yin, Qi,Wang, Rui,Liu, Tian-Fu
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supporting information
p. 4687 - 4691
(2021/03/09)
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- Organic compound, high polymer, mixture, and electronic device
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The invention relates to an organic compound, a high polymer, a mixture and an electronic device. The organic compound has a structure represented by general formula (I) shown in the specification. In the formula (I), each D is independently selected from a single bond, a substituted or unsubstituted aromatic group with 5-40 ring atoms or a substituted or unsubstituted heteroaromatic group with 5-40 ring atoms; each Ar is independently selected from a substituted or unsubstituted aromatic group with 5 to 40 ring atoms or a substituted or unsubstituted heteroaromatic group with 5 to 40 ring atoms; and each L is independently selected from a single bond, an alkenyl group, an alkynyl group, an acyl group, an amido group, a carbonyl group, a sulfonyl group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, or a substituted or unsubstituted thioalkoxy group having 1 to 60 carbon atoms. The organic compound can ensure the device performance during solution processing.
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Paragraph 0118-0121
(2021/08/07)
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- Heptyl-imide derivative as well as preparation method and application thereof
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The invention belongs to the technical field of organic photoelectricity, and discloses a heptyl-imide derivative as well as a preparation method and application thereof. The chemical structure of theheptyl-imide derivative is shown by the following formula, and the heptyl-imide derivative takes an imide derivative as a branch to effectively reduce the molecular orbital energy level and improve the ability to inject electrons. A dendritic molecular structure enables the heptyl-imide derivative to have good solubility and multi-directional carrier transport channels, and is conducive to the formation of a three-dimensional electron transport channel in a film at the same time, so that the heptyl-imide derivative can be well applied to preparation of organic electronic devices.
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Paragraph 0037; 0040; 0044
(2018/06/26)
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- RETRACTED ARTICLE: Tri-: S -triazine (s -heptazine), a novel electron-deficient core for soft self-assembled supramolecular structures
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Self-assembled supramolecular structures formed by disc-shaped molecules, commonly known as discotic liquid crystals (DLCs), have attracted tremendous interest during the past decade due to their potential applications in wide-viewing liquid crystal displays, sensors, photovoltaic solar cells, light emitting diodes, thin film transistors, etc. Since the discovery, only about sixty different core molecules have been explored to prepare about 3500 DLCs. We have realised a new heterocyclic aromatic molecular motif, s-heptazine, which functions as a core fragment for the synthesis of discotic liquid crystals on appropriate functionalization.
- Siva Kumar, Irla,Kumar, Sandeep
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supporting information
p. 11445 - 11448
(2017/10/23)
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- A trinuclear CuII complex with functionalized s-heptazine N-ligands: molecular chemistry from a g-C3N4 fragment
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A new kind of N-ligand based on heptazine derivatives is presented. A trinuclear CuII complex, [(L)2CuII3Cl3](ClO4)3·3CH2Cl2 (L = 2,4,6-tris(di-2-pyridylamino)heptazine), utilizing a pyridine derivative of heptazine has been synthesized and characterized avoiding the inherent solubility problems of heptazine compounds. Thus, this work opens the application of such ligands either in supramolecular chemistry as a larger ligand of the widely used s-triazine derivatives or to provide molecular systems for photocatalysis as heptazine is the fundamental unit of the very promising g-C3N4 2D compound.
- Maxwell, Lindley,Gómez-Coca, Silvia,Weyhermüller, Thomas,Panyella, David,Ruiz, Eliseo
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supporting information
p. 15761 - 15763
(2015/09/15)
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- Process for preparing cyameluric chloride
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The present invention concerns an improved process for obtaining larger quantities (several 10 grams up to kilograms) of pure cyameluric chloride (I) by chlorination of cyameluric acid (C6N7(OH)3) or its alkaline salts followed by fractioned vacuum sublimation.
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Page/Page column 5
(2008/06/13)
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