- Multistimuli-Responsive Luminescence of Naphthalazine Based on Aggregation-Induced Emission
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Stimuli-responsive luminescent materials, which are dependent on changes in physical molecular packing modes, have attracted more and more interest over the past ten years. In this study, 2,2-dihydroxy-1,1-naphthalazine was synthesized and shown to exhibit different fluorescence emission in solution and solid states with characteristic aggregation-induced emission (AIE) properties. A remarkable change in the fluorescence of 2,2-dihydroxy-1,1-naphthalazine occurred upon mechanical grinding, heating, or exposure to solvents. According to the characterization by solid-state fluorescence spectroscopy, X-ray crystallography, differential scanning calorimetry, and X-ray powder diffraction, the fluorescence change could be attributed to transitions between two structurally different polymorphs. These significant properties could also give 2,2-dihydroxy-1,1-naphthalazine more potential applications as a multifunctional material.
- Yao, Xiang,Ru, Jia-Xi,Xu, Cong,Liu, Ya-Ming,Dou, Wei,Tang, Xiao-Liang,Zhang, Guo-Lin,Liu, Wei-Sheng
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- A simple, reversible, colorimetric and water-soluble fluorescent chemosensor for the naked-eye detection of Cu2?+ in ~?100% aqueous media and application to real samples
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A simple, reversible, colorimetric and water-soluble fluorescent chemosensor ADA for the naked-eye detection of Cu2?+ was developed. Sensor ADA showed high selectivity and sensitivity toward Cu2?+ in ~?100% aqueous media over wide pH range. Sensor ADA exhibited a red-shift in the absorption spectra from 466 to 480?nm that is accompanied by significant color change from light yellow to yellowish brown instantaneously. The Cu2?+ recognition is based on the chelation–enhanced fluorescence quenching (CHEQ) effect of the paramagnetic nature. The lowest detection limit is determined to be 15.8?nM, which is much lower than the allowable level of Cu2?+ in drinking water set by U.S. Environmental Protection Agency (~?20?μM) and the World Health Organization (~?30?μM). The 1:1 binding process was confirmed by fluorescence measurements, IR analysis and DFT studies. Moreover, sensor ADA was successfully applied for determination of trace level of Cu2?+ with 4 reuse cycles in various water samples, which affords promising potential in ion-detection field.
- Sun, Tao,Niu, Qingfen,Li, Tianduo,Guo, Zongrang,Liu, Haixia
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- Structure and electronics in dimeric boron π expanded azine and salphen complexes
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Although boron-based fluorophores incorporating nitrogenous chelating ligands have received much attention, there has been little work on examples of boron-salphen and azine derivatives. In this report, we present several π expanded boron salphen type complexes, incorporating both bis(2-hydroxynaphthaldehyde)azine as well as ortho, meta and para variants of the analogous 2-hydroxynaphthaldehyde salphen compounds. For the azine, we observed only the formation of a single BF2 adduct, while for the naphth-phen compounds dimeric BF2 binding was observed. All new compounds were fully characterized via X-ray diffraction, and both DFT and TDDFT studies were carried out to probe the electronic structures of these fluorophores.
- Crandall, Laura A.,Dawadi, Mahesh B.,Burrell, Tailon,Odoom, Adwoa,Ziegler, Christopher J.
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- A highly selective and sensitive chemosensor for instant detection cyanide via different channels in aqueous solution
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A colorimetric and fluorescent cyanide probe bearing naphthol and imine group has been designed and synthesized. This structurally simple probe displays rapid response and high selectivity for cyanide over other common anions (F-, Cl-, Br-, I-, AcO-, H2PO42-,HSO4-,ClO4-, and SCN-) in aqueous solution. The sensing of cyanide was performed via the nucleophilic attack of cyanide anion to imine groups of the probe with a 1:2 binding stoichiometry, and the fluorescence enhancement of the sensor is mainly due to the ICT process improvement. The detection limit for CN- was 4.0×10 -7 M, which is far lower than the WHO guideline of 1.9×10 -6 M. Thus, the present probe should be applicable as a practical system for the monitoring of cyanide concentrations in aqueous samples.
- Zhang, Peng,Shi, Bingbing,You, Xingmei,Zhang, Youming,Lin, Qi,Yao, Hong,Wei, Taibao
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- A single probe for sensing both acetate and aluminum(iii): Visible region detection, red fluorescence and human breast cancer cell imaging
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A single probe (L) can recognise both AcO- and Al3+ as prepared by coupling 2-hydroxy-1-naphthaldehyde with hydrazine. Both the ions provide visible range emission and absorbance upon interaction with the probe allowing their naked eye detections. AcO- sensing is attributed to the formation of hydrogen-bond while Al3+ recognition is due to the combination of three effects, viz. inhibition of excited-state proton transfer (ESPT), CHN isomerization and chelation-enhanced fluorescence (CHEF).
- Ghosh, Abhijit,Sengupta, Archya,Chattopadhyay, Ansuman,Das, Debasis
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- Redox-Mediated Ambient Electrolytic Nitrogen Reduction for Hydrazine and Ammonia Generation
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This work presents a redox-mediated electrolytic nitrogen reduction reaction (RM-eNRR) using polyoxometalate (POM) as the electron and proton carrier which frees the TiO2-based catalyst from the electrode and shifts the reduction of nitrogen to a reactor tank. The RM-eNRR process has achieved an ammonium production yield of 25.1 μg h?1 or 5.0 μg h?1 cm?2 at an ammonium concentration of 6.7 ppm. With high catalyst loading, 61.0 ppm ammonium was accumulated in the electrolyte upon continuous operation, which is the highest concentration detected for ambient eNRR so far. The mechanism underlying the RM-eNRR was scrutinized both experimentally and computationally to delineate the POM-mediated charge transfer and hydrogenation process of nitrogen molecule on the catalyst. RM-eNRR is expected to provide an implementable solution to overcome the limitations in the conventional eNRR process.
- Huang, Shiqiang,Huang, Songpeng,Li, Mengsha,Salla, Manohar,Wang, Qing,Wang, Xun,Xi, Shibo,Yang, Jing,Yang, Yi,Zhang, Feifei,Zhang, Yong-Wei,Zhu, Ming-Ke
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supporting information
p. 18721 - 18727
(2021/07/20)
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- Efficient and versatile catalysis for β-alkylation of secondary alcohols through hydrogen auto transfer process with newly designed ruthenium(II) complexes containing ON donor aldazine ligands
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A new series of ruthenium(II) carbonyl complexes, [RuCl(CO)(EPh3)2(L1-2)] (1–4) (E?=?P or As; H2L1?=?salicylaldazine, H2L2?=?2-hydroxynaphthaldazine), have been assembled from ruthenium(II) precursors [RuHCl(CO)(EPh3)3] and bidentate ON donor Schiff base ligands (H2L1-2). Both ligands and their new ruthenium(II) complexes have been characterized by elemental analyses, spectroscopic methods (UV, IR, NMR (1H, 13C, 31P) as well as ESI mass spectrometry. The molecular structures of H2L1 and 1 have been confirmed by single crystal X-ray diffraction. Based on the above studies, an octahedral coordination geometry around the metal center has been proposed for 1–4. To investigate the catalytic effectiveness of 1–4, the complexes have been used as catalysts in β-alkylation of secondary alcohols with primary alcohols and synthesis of quinolines. The effect of solvent, time, base, catalyst loading, and substituent of the ligand moiety on the reaction was studied. Notably, 1 was a more efficient catalyst toward alkylation of a wide range of alcohols and quinolines synthesis. The reusability of the catalyst was checked and the results showed up to six catalytic runs without significant loss of activity.
- Premkumar, Periyasamy,Manikandan, Rajendran,Nirmala, Muthukumaran,Viswanathamurthi, Periasamy,Malecki, Jan Grzegorz
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p. 3065 - 3079
(2017/10/11)
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- Ratiometric fluorescent pH probes based on aggregation-induced emission-active salicylaldehyde azines
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A series of luminescent salicylaldehyde azines (SAs) containing different electron-accepting substituents (-NO2, -F, and -Cl), electron-donating substituents (-OMe and -NEt2), and a π-extended system (naphthalene ring) are prepared for the application of fluorescent pH probes. These SAs inheriting the aggregation-induced emission (AIE) features display strong blue, green, and red fluorescence with large Stokes shifts in water and solid medium. Combining the advantages of AIE and the chemical reactivity of phenol towards OH-/H+, most of the SAs can be used as ratiometric fluorescent pH probes with a broad pH range (2-14) in water and solid medium (test paper). Moreover, the inherent relationship between their chemical structures and AIE properties/pKa values (7.5-13.3) is studied, which provides unequivocal insights into the design of AIE-active dyes and their applications. This journal is
- Ma, Xiaofeng,Cheng, Jinghui,Liu, Jiaoyan,Zhou, Xiangge,Xiang, Haifeng
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p. 492 - 500
(2015/02/02)
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- Novel de-acylative ring opening of 3-acetyl and 3-bromo acetyl coumarins
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Reaction of 3-acetyl and 3-bromoacetyl coumarins with hydrazine hydrate has resulted in the ring opening of the coumarin moiety. The reaction was attempted with a view to obtain some new pyridazinones and pyrazolones. The reaction did not proceed via the expected pathway instead led to the formation of salicyl azines, the structure of which has been confirmed by single crystal X-ray studies.
- Yaragatti, Naazneen B.,Kulkarni, Manohar V.,Kumar, Gudibande N. A.,Gururow, Tayur N.
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p. 594 - 597,4
(2020/09/15)
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- Orthoamide, LX [1]. N,N,N',N'-Tetraformylhydrazine- a Formylation Agent for Aromatic Compounds of Wide Scope
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The reagent system formed from N,N,N',N'-tetraformylhydrazine (3) and aluminum chloride allows the formylation of aromatic compounds. The scope of the method is comparable with the Olah formylation and the Gross-Rieche procedure, since benzene and fluorobenzene can be formylated. Two formyl groups are transferred from 3 to the aromatic nuclei when a molar ratio 4:1:4 (aluminum chloride/3/aromatic compound) is chosen.
- Kantlehner, Willi,Haug, Erwin,Scherr, Oliver,Stoyanov, Edmont V.,Mezger, Jochen,Ziegler, Georg
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p. 355 - 365
(2007/10/03)
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- INHIBITORS OF METAZOAN PARASITE PROTEASES
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Compositions and methods for treating a patient infected with a metazoan parasite by inhibiting the enzymatic action of the metazoan parasite protease. The compositions comprise at least one metazoan protease inhibitor which binds to the S2 subsite and at least one of the S1 and S1' subsites of the metazoan parasite protease. The methods comprise administration to a patient infected with a metazoan parasite of at least one metazoan protease inhibitor in an amount effective to inhibit the protease of the metazoan parasite, thereby killing the parasite.
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- Kinetics of the reaction of hydrazine with 2-hydroxy-1-naphthaldehyde
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Hydrazine in aqueous solution reacts with 2-hydroxy-1-naphthaldehyde in ethanol leading slowly to highly insoluble yellow reaction product.Based on UV-Vis, IR and mass spectrophotometric studies, the compound is characterized as an aldazine, 2,2'-dihydroxy-1-naphthaldazine.Kinetics of the reaction has been followed by spectrophotometric measurements of the absorbance of the reaction product as a function of time.Under excess the reaction follows a pseudo-first order kinetics.Under excess , also the reaction follows a pseudo-first order kinetids.Yet important kinetic differences have been found between both the processes.Under excess of 2-hydroxy-1-naphthaldehyde, the reaction is controlled thermally, under excess of hydrazine, the rate constant is temperature independent.According to these results the process takes place in two steps with the formation of an intermediate product.The mathematical treatment of the kinetic results is consistent with the proposed mechanism.
- Domenech, R Garcia,Vinuesa, J Manes,Pastor, M Pascual,Buigues, J Mari
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p. 423 - 426
(2007/10/02)
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- PREPARATION AND CHARACTERIZATION OF ALDAZINATE AND KETAZINATE DERIVATIVES OF NIOBIUM(V)
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The reaction of niobium pentaisopropoxide with bibasic tridentate azines (HOC6H4CH=N-N=CHC6H4OH, HOC10H6CH=N-N=CHC10H6OH, and HOC6H4C(CH3)=N-N=C(CH3)C6H4OH) have been investigated in 1:1, 1:2, 1:3 and 2:5 molar ratios in anhydrous benzene.The resulting new derivatives Nb(OPri)3(AZ)2, Nb(OPri)(AZ)2, Nb(AZH)(AZ)2, and Nb2(AZ)5 (where AZ(2-) represents the anion of the azine AZH2) have been characterized by elemental analyses, molecular weight determinations, conductance measurements, and IR, UV and 1H-NMR spectral studies.The integral procedural decomposition temperature (IPDT) of triisopropoxymono(salicylaldehyde azinato)niobium(V), monoisopropoxybis(salicylaldehyde azinato)niobium(V), tris(salicylaldehyde azinato)niobium(V), tri-t-butoxymono(salicylaldehyde azinato)niobium(V), and mono-t-butoxybis(salicylaldehyde azinato)niobium(V) complexes have been calculated and the overall thermal stability of these complexes compared.
- Mookerjee, Manabrenda Nath,Singh, Ran Vir,Tandon, Jagdish Prasad
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p. 109 - 114
(2007/10/02)
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