- Radially Oriented [ n]Cyclo- meta-phenylenes
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Molecular compounds with zigzag carbon nanotube geometries are exceedingly rare. Here we report the synthesis and characterization of carbon-based nanotubes with zigzag geometry, best described as radially oriented [n]cyclo-meta-phenylenes, extending the tubularene family of compounds. By the incorporation of edge-sharing benzene rings into the tubularene's radial π-surface, we have uncovered the first step to give rise to the emergence of radial orbital distribution in zigzag nanorings.
- Castro, Edison,Mirzaei, Saber,Hernández Sánchez, Raúl
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supporting information
p. 87 - 92
(2021/01/09)
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- The Synthesis of Hexaazatrinaphthylene-Based 2D Conjugated Copper Metal-Organic Framework for Highly Selective and Stable Electroreduction of CO2 to Methane
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2D conjugated MOFs have attracted significant interests in recent years owing to their special structural features and promising physical and chemical properties. These intriguing attributes, to a large extent, stem from the nature of incorporated ligands
- Dai, Lu,Li, Jiani,Li, Pengfei,Li, Shuai,Liu, Yanze,Lv, Jianning,Wang, Bo,Yin, Anxiang,Zhu, Zhejiaji
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supporting information
p. 16409 - 16415
(2021/06/27)
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- Robust Photocatalytic Method Using Ethylene-Bridged Flavinium Salts for the Aerobic Oxidation of Unactivated Benzylic Substrates
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7,8-Dimethoxy-3-methyl-1,10-ethylenealloxazinium chloride (1a) was found to be a superior photooxidation catalyst among substituted ethylene-bridged flavinium salts (R=7,8-diMeO, 7,8-OCH2O-, 7,8-diMe, H, 7,8-diCl, 7-CF3 and 8-CF3). Selection was carried out based on structure vs catalytic activity and properties relationship investigations. Flavinium salt 1a proved to be robust enough for practical applications in benzylic oxidations/oxygenations, which was demonstrated using a series of substrates with high oxidation potential, i. e., 1-phenylethanol, ethylbenzene, diphenylmethane and diphenylmethanol derivatives substituted with electron-withdrawing groups (Cl or CF3). The unique capabilities of 1a can be attributed to its high photostability and participation via a relatively long-lived singlet excited state, which was confirmed using spectroscopic studies, electrochemical measurements and TD-DFT calculations. This allows the maximum use of the oxidation power of 1a, which is given by its singlet excited state reduction potential of +2.4 V. 7,8-Dichloro-3-methyl-1,10-ethylenealloxazinium chloride (1 h) can be used as an alternative photocatalyst for even more difficult substrates. (Figure presented.).
- Pokluda, Adam,Anwar, Zubair,Boguschová, Veronika,Anusiewicz, Iwona,Skurski, Piotr,Sikorski, Marek,Cibulka, Radek
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supporting information
p. 4371 - 4379
(2021/04/02)
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- Polyhydroxy compound as well as preparation method and application thereof
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The invention relates to the technical field of metal organic framework materials, in particular to a polyhydroxy compound as well as a preparation method and application thereof. The invention discloses a polyhydroxy compound which contains 2 D π conjuga
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Paragraph 0065-0069
(2021/10/27)
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- A2-A1-D-A1-A2 type non-fullerene acceptors based on methoxy substituted benzotriazole with three different end-capped groups for P3HT-based organic solar cells
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In the last three years, the A2-A1-D-A1-A2 skeleton has become increasingly popular in the design of non-fullerene acceptors (NFAs), and it could match particularly well with the classic p-type polymer of poly(3
- Zhang, Qianqian,Xiao, Bo,Du, Mengzhen,Li, Gongqiang,Tang, Ailing,Zhou, Erjun
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supporting information
p. 10902 - 10909
(2018/10/25)
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- Novel Aryl-Modified Benzoylamino-N-(5,6-dimethoxy-1H-benzoimidazol-2-yl)-heteroamides as Potent Inhibitors of Vascular Endothelial Growth Factor Receptors 1 and 2
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Tumor angiogenesis has become an important target for antitumor therapy, with most current therapies aimed at blocking the vascular endothelial growth factor (VEGF) pathway. The VEGF and its receptors have been implicated as key factors in tumor angiogenesis and are major targets in cancer therapy. A series of aryl-modified benzoylamino-N-(5,6-dimethoxy-1H-benzoimidazol-2-yl)-heteroamides were synthesized from 2-amino-5,6-dimethoxy benzimidazole and aryl-substituted benzoylamino hetero acids. The new compounds were tested for inhibition of VEGF receptors I and II (VEGFR-1 and VEGFR-2). Compound 6e displayed VEGFR-2 inhibitory activity with a 50% inhibition concentration value as low as 0.020 μM in a homogeneous time-resolved fluorescence enzymatic assay. VEGFR-2 active compounds display good activity against VEGFR-1 as well.
- Ashok, Abhishek,Thanukrishnan, Kannan,Bhojya Naik, Halehatty S.,Maridu, Rajendraswami
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p. 1949 - 1956
(2017/05/29)
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- FAR SUPERIOR OXIDATION CATALYSTS BASED ON MACROCYCLIC COMPOUNDS
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An especially robust compound and its derivative metal complexes that are approximately one hundred-fold superior in catalytic performance to the previously invented TAML analogs is provided having the formula (I) wherein Y1, Y2, Y3 and Y4 are oxidation resistant groups which are the same or different and which form 5- or 6-membered rings with a metal, M, when bound to D; at least one Y incorporates a group that is significantly more stable towards nucleophilic attack than the organic amides of TAML activators; D is a metal complexing donor atom, preferably N; each X is a position for addition of a labile Lewis acidic substituent such as (i) H, deuterium, (ii) Li, Na, K, alkali metals, (iii) alkaline earth metals, transition metals, rare earth metals, which may be bound to one or more than one D, (iv) or is unoccupied with the resulting negative charge being balanced by a nonbonded counteraction; at least one Y may contain a site that is labile to acid dissociation, providing a mechanism for shortening complex lifetime. The new complexes deliver catalytic performances that promise to revolutionize multiple oxidation technology spaces including water purification.
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Page/Page column 81
(2017/04/11)
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- Expanding the aqueous-based redox-facilitated self-polymerization chemistry of catecholamines to 5,6-dihydroxy-1H-benzimidazole and its 2-substituted derivatives
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Aqueous-base redox-facilitated self-polymerization can be performed with 5,6-dihydroxy-1H-benzimidazole (DHBI) to generate polymeric material that is analogous to poly(dopamine) (PDA), proving the possibility to expand the catecholamine-exclusive chemistr
- Fan, Ka Wai,Peterson, Matthew B.,Ellersdorfer, Peter,Granville, Anthony M.
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p. 25203 - 25214
(2016/03/22)
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- Development and in vivo quantitative magnetic resonance imaging of polymer micelles targeted to the melanocortin 1 receptor
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Recent emphasis has focused on the development of rationally designed polymer-based micelle carriers for drug delivery. The current work tests the hypothesis that target specificity can be enhanced by micelles with cancer-specific ligands. In particular,
- Barkey, Natalie M.,Preihs, Christian,Cornnell, Heather H.,Martinez, Gary,Carie, Adam,Vagner, Josef,Xu, Liping,Lloyd, Mark C.,Lynch, Vincent M.,Hruby, Victor J.,Sessler, Jonathan L.,Sill, Kevin N.,Gillies, Robert J.,Morse, David L.
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p. 6330 - 6338
(2013/09/23)
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- 2,1,3-Benzoxadiazole and 2,1,3-benzothiadiazole-based fluorescent compounds: Synthesis, characterization and photophysical/electrochemical properties
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Six new fluorescent compounds derived from 2,1,3-benzoxadiazole and 2,1,3-benzothiadiazole heterocycles with varying numbers of alkoxy chains were successfully synthesized. Sonogashira cross-coupling was used as the key synthetic step to link the central and terminal aromatic units through an acetylenic linker unit which ensures molecular planarity and extension of the conjugation. All of the synthesized compounds showed UV-vis absorption in the 426-437 nm range with reasonably high molar extinction coefficients. All six compounds emit in the green region of the visible spectrum with reasonably large Stokes shifts (95-107 nm) and medium emission efficiencies (Φf = 0.27-0.32). Electrochemical studies showed that the compounds have closely spaced HOMO and LUMO energy levels and that they may present good electron transporting properties.
- Behramand, Behramand,Molin, Fernando,Gallardo, Hugo
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p. 600 - 605
(2012/11/06)
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- Synthesis, electrochemical and optical absorption properties of new perylene-3,4:9,10-bis(dicarboximide) and perylene-3,4:9,10-bis(benzimidazole) derivatives
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A series of perylene-3,4:9,10-bis(dicarboximide) (PBI) and perylene-3,4:9,10-bis(benzimidazole) (PTCBI) derivatives that are di-or tetra-substituted at the bay region by electron-donating or electron-withdrawing groups have been synthesized as soluble n-type semiconductors. Optical absorption spectroscopy and electrochemical analysis show that the nature of substitution at the bay region plays a crucial role in the modulation of the electronic properties of these PBI and PTCBI derivatives. Examination of these optical and electrochemical data in the light of energy levels identified by theoretical studies allowed a relationship between the structure and the electronic properties to be established. A relationship between the structure and electronic properties of n-type semiconductors from perylene-3,4:9,10- bis(dicarboximide) (PBI) and perylene-3,4:9,10-bis(benzimidazole) (PTCBI) series substituted at the bay region by electron-donating or electron-withdrawing groups has been established by using the complementary techniques of absorption spectroscopy, electrochemical analysis and theoretical calculations. Copyright
- Perrin, Lara,Hudhomme, Pietrick
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experimental part
p. 5427 - 5440
(2011/11/29)
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- Antineoplastic agents. 552. Oxidation of combretastatin A-1: Trapping the o-quinone intermediate considered the metabolic product of the corresponding phosphate prodrug
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The very unstable (4 and tetrabutylammonium bromide in water/dichloromethane. Immediate reaction
- Pettit, George R.,Thornhill, Andrew J.,Moser, Bryan R.,Hogan, Fiona
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experimental part
p. 1561 - 1563
(2009/07/10)
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- Gallic esters of 4,5-dinitrocatechol as potential building blocks for thermotropic liquid crystals
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A series of unsubstituted and 1,4-disubstituted gallic catecholates 1, 6 and 7 as possible candidates for wedge-shaped mesogens were prepared starting from the respective benzene derivatives 2a-c and gallic esters 5a-h. The mesomorphic properties were inv
- Judele, Roxana,Laschat, Sabine,Baro, Angelika,Nimtz, Manfred
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p. 9681 - 9687
(2007/10/03)
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- Rapid synthesis of new discotic liquid crystals based on diquinoxalino[2,3-a:2′,3′-c]phenazine containing hexakis(alkoxy) side arms
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The condensation of 1,2-bisalkoxy-4,5-diaminobenzene 2a-e derivatives with freshly prepared hexaketocyclohexane give hexakis(alkoxy)diquinoxalino[2,3-a:2′,3′-c]phenazines in good yield. DSC and polarization microscopy showed HATOC6 has both the crystalline (K) to mesophase (M) and the mesophase (M) to isotropic (I) phase transitions. Importantly, the alkoxy substituted compound synthesized showed an M-I transition because of greater stability, whereas the reported alkyl-thiol decomposes after the mesophase.
- Ong, Chi Wi,Liao, Su-Chih,Chang, Tsu Hsing,Hsu, Hsiu-Fu
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p. 1477 - 1480
(2007/10/03)
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- Lipophilic metal-salicylideneimine-crown ether hybrids - Ditopic carriers in the facilitated transport of amphiphilic molecules across bulk liquid membranes
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The crown ether-functionalized MnIII salicylaldimine complexes manganese (III) 4,5-bis (3,5-di-tert-butylsalicylideneimine)benzo-18-crown-6-X [X = Cl-, I-, CH3COO-,(CH3)3CCOOsup
- Pike, Jay D.,Rosa, Dell T.,Coucouvanis, Dimitri
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p. 761 - 777
(2007/10/03)
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- A mild one-pot procedure for the polynitration of activated arenes. Convenient preparation of dinitro- and trinitrodialkoxybenzenes
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When first treated with an excess of nitrogen dioxide alone and then in the presence of ozone at low temperature, dialkoxybenzenes are smoothly and stepwise polynitrated in a one-pot manner to afford the corresponding dinitro or trinitro derivatives in good yield.
- Nose,Suzuki
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p. 1539 - 1542
(2007/10/03)
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- Salicylaldimine-crown ether ditopic receptor molecules
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The present invention relates generally to carriers for transport of amino acid, amino acid derivatives and other biologically important molecules such as catecholamines and neurotransmitters. In particular, the present invention relates to ditopic recept
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- Long-lived homogenous oxidation catalysts
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A robust chelate complex is provided having the formula: STR1 wherein M is a metal, preferably a transition metal; Z is an anionic donor atom, at least three of which are nitrogen and the other is preferably nitrogen or oxygen; L1 is a labile l
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- Alkyl, azido, alkoxy, and fluoro-substituted and fused quinoxalinediones
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Methods of treating or preventing neuronal loss associated with stroke, ischemia, CNS trauma, hypoglycemia, and surgery, as well as treating neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, and Down's syndrome, treating or preventing the adverse consequences of the hyperactivity of the excitatory amino acids, as well as treating anxiety, chronic pain, convulsions, and inducing anesthesia are disclosed by administering to an animal in need of such treatment an alkyl or azido-substituted 1,4-dihydroquinoxaline-2,3-dione or pharmaceutically acceptable salts thereof, which have high binding to the glycine receptor.
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- Iron(III)-catalysed nitration of non-activated and moderately activated arenes with nitrogen dioxide-molecular oxygen under neutral conditions
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In the presence of molecular oxygen and a catalytic amount of tris(pentane-2,4-dionato)iron(III), non-activated and moderately activated arenes, which include alkylbenzenes, halogenobenzenes, phenolic ethers, naphthalene and derivatives, can be nitrated with nitrogen dioxide at ice-bath temperature or below to give the corresponding nitro derivatives in fair to good yields. An electron-transfer mechanism has been proposed, where an activated NO2-FeIII complex plays a key role in the cyclic process for converting arenes into nitroarenes.
- Suzuki, Hitomi,Yonezawa, Shuji,Nonoyama, Nobuaki,Mori, Tadashi
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p. 2385 - 2389
(2007/10/03)
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- Convenient Nitration of Anisole and its Derivatives using an NO-O2 System
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Anisole and its derivatives are regioselectively nitrated by use of nitrogen monoxide-molecular dioxygen mixed gas under mild conditions.
- Mizuno, Kazuhiko,Tamai, Toshiyuki,Hashida, Isao,Otsuji, Yoshio,Inoue, Hiroo
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p. 284 - 285
(2007/10/03)
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- Acetoxylation of 6,7-dialkoxy-substituted 1,4-dihydroquinoxaline-2,3-diones (QXs) using fuming nitric acid in acetic acid: A facile synthesis of 5-acyloxy-6,7-dialkoxy QXs
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Treatment of 6,7-dialkoxy-1,4-dihydroquinoxaline-2,3-diones 3 with fuming nitric acid in acetic acid at 25°C resulted in an acetoxylation reaction, giving 5-acetoxy-6,7-dialkoxy-1,4-dihydroquinoxaline-2,3-diones 4 in moderate yields. A mechanism involving ipso attack of nitronium ion as the first step is proposed.
- Zhou, Zhang-Lin,Weber, Eckard,Keana, John F. W.
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p. 7583 - 7586
(2007/10/02)
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- Potent Quinoxaline-Spaced Phosphono α-Amino Acids of the AP-6 Type as Competitive NMDA Antagonists: Synthesis and Biological Evaluation
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A series of α-amino-3-(phosphonoalkyl)-2-quinoxalinepropanoic acids was synthesized and evaluated for NMDA receptor affinity using a CPP binding assay.Functional antagonism of the NMDA receptor complex was evaluated in vitro using a stimulated TCP binding assay and in vivo by empolying an NMDA-induced seizure model.Some analogues also were evaluated in the -glycine binding assay.Several compounds of the AP-6 type show potent and selective NMDA antagonistic activity both in vitro and in vivo.In particular α-amino-7-chloro-3-(phosphonomethyl)-2-quinoxalinepropanoic acid (1) d isplayed an ED50 of 1.1 mg/kg ip in the NMDA lethality model.Noteworthy is α-amino-6,7-dichloro-3-(phosphonomethyl)-2-quinoxalinepropanoic acid (3) with a unique dual activity, displaying in the NMDA receptor binding assay an IC50 of 3.4 nM and in the glycine binding assay an IC50 of 0.61 μM.
- Baudy, Reinhardt B.,Greenblatt, Lynne P.,Jirkovsky, Ivo L.,Conklin, Mary,Russo, Ralph J.,et al.
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p. 331 - 342
(2007/10/02)
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- NMR studies of N-(benzimidazol-2-yl)pyridinium derivatives: QSAR with the anti-leishmanial activity and their carbon-13 NMR chemical shifts
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Quantitative structure-activity-relationships between the in vitro anti-leishmanial activity of N-benzimidazolyl-2,4,6-triphenylpyridinium salts 6 and pyridinium benzimidazolate betaines 7 and their 13C-NMR chemical shifts have been studied, in order to ascertain the influence of the benzimidazole substituents upon anti-leishmanial activity.The calculated 13C-chemical shifts allow the selection of a representative subset of compounds.Several new N-benzimidazolylpyridinium derivatives 6 and 7 have been prepared.Among them, 5-methoxy-1-methylbenzimidazole 21 and 6-methoxy-1-methylbenzimidazole 22 derivatives have high anti-leishmanial activity in vitro and compound 22 shows an interesting activity in vivo although host toxicity is present.
- Alcalde, E,Dinares, I,Frigola, J
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p. 633 - 642
(2007/10/02)
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- Stable highly oxidizing cobalt complexes of macrocyclic ligands
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The first crystallographically characterized neutral square-planar complex of cobalt in an oxidation state higher than 2+, Co(η44-1), is reported. Structural data for this new class of compounds indicate that the macrocycle in Co(η4-1) is Equation Presented X = Cl, Co(η4-1) X = H, Co(η4-2) X = MeO, Co(η4-3) noninnocent; however, EPR data in toluene at 5.9 K (S = 1/2; g1 = 2.558, g2 = 2.170, g3 = 2.017; A2 ≈ 15 G) show that the metal center is the primary reisdence site of the unpaired electron. Co(η4-1) is a stable, yet potent, oxidant which is soluble in benzene and slightly soluble in pentane. The Co(η4-1)/[CoIII(η4-1)]- couple is reversible and found at 0.550 V vs Fc+/Fc in CH2Cl2 (ca. 1.26 V vs NHE). Co(η4-1) slowly oxidized water, yielding H[CoIII(η4-1)], which may also be prepared by the reaction of [CoIII(η4-1)]- with HBF4. Both the redox and the acid/base chemistries of [CoIII(η4-1)]- are reversible. Electrochemical and EPR data are also presented for Co(η4-2) and Co(η4-3).
- Collins, Terrence J.,Powell, Richard D.,Slebodnick, Carla,Uffelman, Erich S.
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p. 8419 - 8425
(2007/10/02)
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- REACTION OF TETRANITRODIBENZO-18-CROWN-6 WITH SODIUM ALKOXIDES
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It is shown that the reaction of tetranitrodibenzo-18-crown-6 with sodium alkoxides in aprotic solvents at room temperature occurs with initial cleavage of the macroheterocycle and formation of an intermediate - substituted o-dinitrobenzene - whereas the
- Ivanov, E. I.,Polishchuk, A. A.,Avraamov, S. M.,Ivanova, R. Yu.
-
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- Synthesis of Dimethoxy- and Dioxano-annellated Benzofuroxans from o-Dinitroarenes
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Thermolysis of 4,5-dinitroveratrole 1a in the presence of sodium azide and dimethylsulfoxide gives the new 5,6-dimethoxybenzofuroxan, 2a, whereas 3,4,5-trinitroveratrole led to the new 5(7),6-dimethoxy-4-nitrobenofuroxans 2e, 3e via a nucleophilic substit
- Eswaran, S. V.,Sajadian, S. K.
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p. 803 - 806
(2007/10/02)
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- THE NUCLEOPHILIC AROMATIC PHOTOSUBSTITUTIONS OF 4,5-DINITROVERATROLE WITH AMINES. PHOTOREDUCTIONS OF AROMATIC DINITROCOMPOUNDS
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4,5-Dinitroveratrole is effectively photosubstituted by amines with relatively high ionization potential such as methylamine, n-butylamine and ethyl glycinate, but is mainly photoreduced when amines with relatively low ionization potential, such as dimethyl or trimethylamine are used.The photoreduction of several aromatic dinitrocompounds by triethylamine gives nitroanilines.A mechanistic scheme is proposed embracing our photosubstitutions and photoreductions, based on our experimental results and on MINDO/3 calculations of the ground states and the more likely intermediates.
- Marquet, Jorge,Moreno-Manas, Marcial,Vallribera, Adelina,Virgili, Albert,Bertran, Joan,et al.
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p. 351 - 360
(2007/10/02)
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- Heterocyclic Systems Containing Brigdehead Nitrogen Atom: Part LII - Synthesis of 6,7-Dimethoxy and 5,8-Dimethoxy Thiazolobenzimidazol-3(2H)-ones, Thiazolobenzimidazoles and 2,3-Dihydrothiazolobenzimidazoles
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5,6-Dimethoxy- (IIIa) and 4,7-dimethoxy-2-mercaptobenzimidazoles (IIIb), obtained by the successive reactions involving nitration of dimethoxybenzenes (Ia,b), reduction of the o-dinitrobenzenes (IIa,b) with Raney nickel and hydrazine hydrate followed by t
- Narayan, Sat,Kumar, Vinod,Pujari, H. K.
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p. 267 - 270
(2007/10/02)
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