3029-19-4Relevant articles and documents
Signaling of hypochlorous acid by selective deprotection of dithiolane
Hwang, Jiyoung,Choi, Myung Gil,Bae, Jihee,Chang, Suk-Kyu
, p. 7011 - 7015 (2011)
The selective signaling of hypochlorous acid by dithiolane-protected pyrene-aldehyde was investigated. Dithiolane derivative of pyrene-aldehyde was efficiently deprotected by hypochlorous acid to its corresponding aldehyde, which resulted in a prominent UV-vis and turn-on type fluorescence signaling. The signaling was not affected by the presence of other common alkali, alkaline earth metal ions, and anions. Interference from Hg2+ ions could be successfully circumvented by using Chelex-100 resin. Dithiolane also provided selectivity toward hypochlorous acid over other commonly used oxidant of hydrogen peroxide.
Photoprocesses in Diphenylpolyenes. 3. Efficiency of Singlet Oxygen Generation from Oxygen Quenching of Polyene Singlets and Triplets
Chattopadhyay, S. K.,Kumar, C. V.,Das, P. K.
, p. 670 - 673 (1985)
The efficiencies of singlet oxygen (1O2*) photogeneration from the oxygen quenching of the excited states (singlet/triplet) of retinal-related polyenals and diphenylpolyenes have been measured in cyclohexane and methanol by 337.1-nm laser flash photolysis.The 1O2* yields are essentially quantitative with all-trans-retinal and its lower and higher homologues as triplet photosensitizers.For all-trans-1,6-diphenyl-1,3,5-hexatriene (DPH) and all-trans-1,8-diphenyl-1,3,5,7-octatetraene (DPO), both singlet and triplet quenching by oxygen contribute to the formation of 1O2*; significant fractions (0.1-0.7) of the oxygen-induced intersystem crossing in these polyene systems take place without energy transfer to oxygen.The triplet-mediated 1O2* yield obtained by steady-state photolysis of all-trans-1,4-diphenyl-1,3-butadiene (DPB) under energy-transfer sensitization by pyrene-1-aldehyde in O2-saturated benzene is less than unity (0.7 +/- 0.1), suggesting possible fractional quenching by oxygen at an orthogonal geometry of DPB triplet (responsible for "nonproduction" of 1O2*).
OFF-ON fluorescent detection of thymidine nucleotides by a zinc(II)-cyclen complex bearing two diagonal pyrenes
Zeng, Zhanghua,Spiccia, Leone
, p. 12941 - 12944 (2009)
Of a ZnII-cyclen complex bearing two diagonal pyrenes (see picture) has been developed that has a high affinit for thymidine nucleotides, and a much greater enhancement in excimer emission for thymidine triphosphate,-diphosphate and-mono-phosphate than for the other DNA bases and a v of nucleotides.
"Shadow" Synthesis, Structure, and Electronic Properties of [2.2](1,6)(1,8)Pyrenophane-1-monoene
Unikela, Kiran Sagar,Tabasi, Zahra A.,Dawe, Louise N.,Zhao, Yuming,Bodwell, Graham J.
, p. 4405 - 4412 (2021)
An unexpected side product of a McMurry reaction was found to be a new [2.2]pyrenophane consisting of two pyrene units with different substitution patterns as well as different types and degrees of distortion from planarity. The new pyrenophane exhibits both monomer and intramolecular excimer fluorescence. Natural bond orbital (NBO) analysis revealed that there is an intramolecular charge-transfer interaction from the more distorted pyrene system to the less distorted one. The origin of the new pyrenophane was traced back to an impurity that was present a full five steps prior to the McMurry reaction from which it was isolated. The pathway to the pyrenophane shadowed that of the main synthetic route.
1,2-Dioxetanes from Vinyl Aromatics
Posner, Gary H.,Weitzberg, Moshe,Nelson, William M.,Murr, Brown L.,Seliger, Howard H.
, p. 278 - 279 (1987)
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An Azoaromatic Ligand as Four Electron Four Proton Reservoir: Catalytic Dehydrogenation of Alcohols by Its Zinc(II) Complex
Pramanick, Rajib,Bhattacharjee, Rameswar,Sengupta, Debabrata,Datta, Ayan,Goswami, Sreebrata
, p. 6816 - 6824 (2018)
Electroprotic storage materials, though invaluable in energy-related research, are scanty among non-natural compounds. Herein, we report a zinc(II) complex of the ligand 2,6-bis(phenylazo)pyridine (L), which acts as a multiple electron and proton reservoir during catalytic dehydrogenation of alcohols to aldehydes/ketones. The redox-inactive metal ion Zn(II) serves as an oxophilic Lewis acid, while the ligand behaves as efficient storage of electron and proton. Synthesis, X-ray structure, and spectral characterizations of the catalyst, ZnLCl2 (1a) along with the two hydrogenated complexes of 1a, ZnH2LCl2 (1b), and ZnH4LCl2 (1c) are reported. It has been argued that the reversible azo-hydrazo redox couple of 1a controls aerobic dehydrogenation of alcohols. Hydrogenated complexes are hyper-reactive and quantitatively reduce O2 and para-benzoquinone to H2O2 and para-hydroquinone, respectively. Plausible mechanistic pathways for alcohol oxidation are discussed based on controlled experiments, isotope labeling, and spectral analysis of intermediates.
Synthesis of 1-functionalized pyrenes from 1-lithiopyrene, and their application as fluorescent probes for the components of the Ginkgo biloba L. leaves extract
Kovalev,Slovesnova,Kopchuk,Zyryanov,Taniya,Rusinov,Chupakhin
, (2014)
Pyrene-1-carbaldehyde, pyrene-1-carboxylic acid, and 1-aminomethylpyrene were obtained from 1-lithiopyrene generated in situ from 1-bromopyrene. 1-Aminomethylpyrene was used for the fluorescent detection of terpene trilactones, components of the Ginkgo bi
Molecular engineering of pyrene carbazole dyes with a single bond and double bond as the mode of linkage
Unny, Divya,Kandregula, Ganapathi Rao,Sivanadanam, Jagadeeswari,Ramanujam, Kothandaraman
supporting information, p. 16511 - 16525 (2020/10/14)
Both carbazole and pyrene are electron-rich aromatic systems and are expected to be potential donors when used in a push-pull dye architecture in the field of DSSC technology. Herein, two novel pyrene-carbazole dyes bearing single bond (PC1) and double bond (PC2) linkers and cyano-acrylic acid as an acceptor were synthesized. The dye with a double bond spacer (PC2) in the presence of CDCA achieved an improved power conversion efficiency of 6.30% with a short circuit current of 11.59 mA cm-2, open circuit potential (VOC) of 0.80 V, and a fill factor of 0.68 under standard global AM 1.5G solar conditions. Cyclic voltammetry and density functional theory studies indicate that the incorporation of two donors improved the ease of oxidation of the dyes, which resulted in a high VOC. Despite having a rigid single bond, the charge transfer of the PC1 dye is found to be poor, which affected the photovoltaic performance. The dihedral angle measured at each joint of the optimized dye indicated that PC2 exhibits excellent intramolecular charge transfer due to the near planarity in the structure. Besides, the high electron lifetime in the excited state of PC2 makes it the best performer among the three dyes studied.
Flavin Nitroalkane Oxidase Mimics Compatibility with NOx/TEMPO Catalysis: Aerobic Oxidization of Alcohols, Diols, and Ethers
Thapa, Pawan,Hazoor, Shan,Chouhan, Bikash,Vuong, Thanh Thuy,Foss, Frank W.
, p. 9096 - 9105 (2020/08/14)
Biomimetic flavin organocatalysts oxidize nitromethane to formaldehyde and NOx - providing a relatively nontoxic, noncaustic, and inexpensive source for catalytic NO2 for aerobic TEMPO oxidations of alcohols, diols, and ethers. Alcohols were oxidized to aldehydes or ketones, cyclic ethers to esters, and terminal diols to lactones. In situ trapping of NOx and formaldehyde suggest an oxidative Nef process reminiscent of flavoprotein nitroalkane oxidase reactivity, which is achieved by relatively stable 1,10-bridged flavins. The metal-free flavin/NOx/TEMPO catalytic cycles are uniquely compatible, especially compared to other Nef and NOx-generating processes, and reveal selectivity over flavin-catalyzed sulfoxide formation. Aliphatic ethers were oxidized by this method, as demonstrated by the conversion of (-)-ambroxide to (+)-sclareolide.
