13755-95-8Relevant articles and documents
Selective chromogenic detection of cyanide in aqueous solution – Spectral, electrochemical and theoretical studies
Lakshmi, P. Raja,Jayasudha,Elango, Kuppanagounder P.
, p. 318 - 323 (2019)
A bisimidazole ensemble (R) possessing naphthoquinone as signaling unit is synthesized and characterized using 1H and 13C NMR and LC-MS spectral techniques. Anion sensing behaviour of the receptor has been investigated using electronic and fluorescence spectral techniques. The receptor exhibits a striking colour change from yellow to brown selectively with cyanide in aqueous HEPES buffer-DMSO (1:1 v/v) medium with a detection limit of 1 μM. Job's continuous variation method suggests that the stoichiometry of the interaction is 1:2 (R:CN?). The binding constant for receptor-cyanide complex was found to be 8.7 × 102 M?1. The mechanism of detection of cyanide occurs via deprotonation of imidazole N-H protons, which is well supported by electrochemical study. DFT based theoretical calculations shows that the energy gap between HOMO and LUMO decreases from 3.3086 (in R) to 1.7799 eV (in R + CN?), which is responsible for the red-shift observed in the UV–Vis spectrum of R upon addition of cyanide ions. The present quinone-bisimidazole based receptor shows few advantages over similar bisimidazoles reported elsewhere.
Long-Life, High-Rate Lithium-Organic Batteries Based on Naphthoquinone Derivatives
Lee, Joungphil,Kim, Hoon,Park, Moon Jeong
, p. 2408 - 2416 (2016)
We report the facile synthesis of new naphthoquinone (NQ) derivatives for use in lithium-organic batteries to improve performance. The rational design of these NQ derivatives is based on theoretical calculations. Our lithium-organic batteries demonstrate remarkable charge-discharge properties, for example, a high discharge capacity of 250 mAh g-1 (363 mAh cm-3), discharge potential plateaus in the range of 2.3-2.5 V, and 99% capacity retention after 500 cycles at 0.2C. In particular, the batteries had excellent rate performance up to 50C with reversible redox behavior, unlike most other organic cathode materials. The key to success was a simple molecular substitution, addition of amino groups at the 2- and 3- positions of the NQ ring, yielding 2,3-diamino-1,4-naphthoquinone (DANQ). DANQ has an exceptionally low band gap of 2.7 eV and greater than 20-fold enhancement in the lithium diffusion rate compared to unmodified NQ. The fundamental shortcoming of the organic molecules, i.e., their solubility in the electrolyte, was resolved by covalent linking of the amino groups to the surfaces of the cathode framework. The cyclization of amino groups in DANQ yielded 1H-naphtho[2,3-d]imidazole-4,9-dione (IMNQ), enabled us to achieve a 0.15 V enhancement in the redox potential owing to the delocalized electron distribution in the heteroaromatic ring. Our work suggests that NQ derivatives with modulated charge/ion transport properties are a viable alternative to the more widely studied lithium metal oxides.
Spectroscopic, electrochemical and theoretical studies on anion recognition by receptors with redox active ferrocene and quinone centers bridged by imidazole
Satheshkumar, Angupillai,Manivannan, Ramalingam,Elango, Kuppanagounder P.
, p. 98 - 106 (2014)
Two chromogenic sensors possessing two redox-active centers (quinone and ferrocene) bridged by imidazole anion recognition group have been synthesized and screened for their anion sensing properties. Both the receptors exhibited dramatic color change upon the addition of fluoride and cyanide ions so that we could finish anion recognition by visual detection without resorting to any spectroscopic instruments. The evaluation of the receptor interaction with anions was performed by UV-Vis titration experiments in DMSO. UV-Vis titrations revealed that receptor 1, wherein the imidazole moiety is directly attached to naphthoquinone unit, exhibited a relatively larger bathochromic shift of the intramolecular charge transfer (ICT) band than 2 in which the imidazole receptor unit is away from the quinone moiety. Receptor 1 displays a higher (Δδ = 0.269, 0.352 ppm) downfield shift of the imidazole N-H proton than 2 (Δδ = 0.070, 0.122 ppm) indicating that the anion binding pattern of these chemosensors was H-bond interaction. Also, the UV-Vis and 1H NMR results indicated that the receptor-CN- binding is relatively stronger than receptor-F- interaction. The redox activities of the quinone and ferrocenyl centers in 1 and 2 have been characterized by cyclic and differential pulse voltammetries. Electrochemical titrations revealed that the receptor 1 sensed CN- ions with an anodic shift of -198 mV in the oxidation potential of ferrocene moiety when compared to -188 mV with the receptor 2. Addition of incremental amounts of F- and CN- ions, to these two receptors, shifts the E 1/2 of the quinone redox couple to less negative potentials. DFT (B3LYP/3-21G) calculations performed for both free receptor and receptor-anion complexes are in good agreement with the observed spectroscopic and electrochemical data.
Are N,N-dihydrodiazatetracene derivatives antiaromatic?
Miao, Shaobin,Brombosz, Scott M.,Schleyer, Paul V R.,Wu, Judy I.,Barlow, Stephen,Marder, Seth R.,Hardcastle, Kenneth I.,Bunz, Uwe H. F.
, p. 7339 - 7344 (2008)
The synthesis and X-ray characterization of two new dialkynylated diazatetracenes and the corresponding N,N-dihydrodiazatetracenes are reported. The dialkynylated heteroacenes are packed in a brick-wall motif that enforces significant overlap of their π-faces. Cyclic voltammetry indicates that the dehydrogenated forms are easily reduced to their radical anions in solution. The planarity of these species validates the discussion of their aromaticity. Nucleus Independent Chemical Shift (NICS) computations demonstrate that both of these 20 π and 24 π electron systems are aromatic. Both experimental and computational results suggest that the aromaticity of the dihydroheteroacenes is reduced.
A fused donor-acceptor system based on an extended tetrathiafulvalene and a ruthenium complex of dipyridoquinoxaline
Chesneau, Bertrand,Hardouin-Lerouge, Marie,Hudhomme, Pietrick
, p. 4868 - 4871 (2010)
An application of the Horner-Wadsworth-Emmons reaction carried out on a ruthenium compound as the electrophilic precursor is described for the synthesis of fused donor-acceptor system 1 based on an extended tetrathiafulvalene and a ruthenium complex of dipyridoquinoxaline units.
Use of naphthoquinone derivative as inhibitor for IDO1 and/or TDO
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Paragraph 0097; 0101-0102, (2020/01/31)
The invention discloses a use of a naphthoquinone derivative as an inhibitor for IDO1 and/or TDO. The derivative is shown as a general formula (I), and the definition of each substituent is detailed in the specification. The compound represented by the general formula (I) has an inhibitory effect on indoleamine-2,3-dioxygenase 1 (IDO1) and/or tryptophan-2,3-dioxygenase (TDO), and can be used for treating diseases with IDO1- and/or TDO-mediated tryptophan metabolism as pathological features, including but not limited to tumors, autoimmune diseases, infectious diseases, Alzheimer's disease, depression, and anxiety disorder.
