- Li+-Induced fluorescent metallogel: A case of ESIPT-CHEF and ICT phenomenon
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A fluorescent metallogel (1percent w/v) has been synthesized from non-fluorescent ingredients viz. the smallest possible low molecular weight aromatic symmetrical ligand H2SA (1) and LiOH in a chloroform and methanol mixture. The chelation of Li+ is not only responsible for the inhibition of excited state intramolecular proton transfer (ESIPT) or the origin of fluorescence through chelation enhanced fluorescence (CHEF) in 1, but also for aggregation leading to gelation. The metallogel obtained from 1/Li+ reveals a fibrous morphology while 1 with other, bigger size, alkali metal ions like Na+/K+/Cs+ demonstrates the growth of crystals with different shapes. The effect of the size of the alkali metal ion over gel formation is well explored by FTIR, UV-vis, fluorescence, average lifetime measurements, SEM and PXRD. The metallogel shows multi-stimuli responsive behaviour towards thermal and mechanical stress as well as reswelling properties. The regioisomer H2PBA (2) also shows emission upon treatment with LiOH due to the presence of intramolecular charge transfer (ICT), this is well established by various experiments. The mechanism of gel formation is well established by FTIR, 1H NMR, UV-vis, fluorescence, lifetime measurements, SEM and single crystal and powder XRD instrumental techniques. The involvement of various phenomena in gel formation has been further supported by other synthesized model compounds viz. H2MBA (3), PMO (4), H2SEA (5) and H2SPA (6). True gel phase material is proved by detailed rheological experiments.
- Dixit, Manish Kumar,Dubey, Mrigendra
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p. 23762 - 23772
(2018/09/29)
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- Anomalous reaction of hydrazine hydrate with 5-arylidene barbiturates: Formation of benzalazines
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Reaction of 5-arylidene barbiturates (3a-i) with hydrazine hydrate resulted in the unusual formation of novel benzalazines (5a-i) in 70-90% yield rather than the expected pyrazole fused pyrimidines.
- Goudgaon,Upendar Reddy, Ch.,Patil, Sharanabasappa,Sheshikant
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p. 277 - 282
(2019/01/21)
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- Biomimetic aerobic oxidative hydroxylation of arylboronic acids to phenols catalysed by a flavin derivative
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Flavin-catalysed oxidative hydroxylation of substituted arylboronic acids by molecular oxygen with the assistance of hydrazine or ascorbic acid resulted in phenols in high yields. This mild organocatalytic protocol is compatible with a variety of functional groups and it is alternatively usable for transformation of alkylboronic acids to alcohols. Reaction takes place also in water and fulfils criteria for a green procedure.
- Kotoucova, Hana,Strnadova, Iveta,Kovandova, Martina,Chudoba, Josef,Dvorakova, Hana,Cibulka, Radek
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supporting information
p. 2137 - 2142
(2014/03/21)
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- ASYMMETRIC AZINE COMPOUND AND METHOD FOR PRODUCING THE SAME
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Disclosed are a novel asymmetric azine compound (I) and a method for producing an asymmetric azine compound (I) which is characterized in that an aldehyde compound (III) and hydrazine are reacted in an alcohol solvent at a molar ratio (aldehyde compound (
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Page/Page column 17-19
(2011/04/25)
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- Synthesis of azines in solid state: Reactivity of solid hydrazine with aldehydes and ketones
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Highly conjugated azines were prepared by solid state grinding of solid hydrazine and carbonyl compounds such as aldehydes and ketones, using a mortar and a pestle. Complete conversion to the azine product is generally achieved at room temperature within 24 h, without using solvents or additives. The solid-state reactions afford azines as the sole products with greater than 97% yield, producing only water and carbon dioxide as waste.
- Lee, Byeongno,Hyung Lee, Kyu,Cho, Jaeheung,Nam, Wonwoo,Hur, Nam Hwi
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supporting information; experimental part
p. 6386 - 6389
(2012/02/01)
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- Synthesis of functionalized diaryl alkancs from azines
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Substituted diaryl alkanes arc synthesized from bcnzalazines and acctophenone/propiophenone azines via Friedel Craft's reaction with substituted mono- and poly-nuclear aromatic hydrocarbons. Diaryl methanes/ethanes and propanes are obtained by reaction with benzalazine, N,N'-bis (I-phenyl) azine and N, N'-bis (I-propyl) azine, respectively.
- Manih, Rudolf M.,Myrboh, Bekington
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experimental part
p. 146 - 151
(2009/12/01)
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- Selective and convenient protection of aldehydes as azines under solvent-free conditions
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Aldehydes can be easily protected as azines in the presence of hydrazine monohydrochloride and ferric chloride under solvent-free conditions. The major advantages of this method are: operational simplicity, ready availability, selectivity, general applicability, mild reaction conditions with low cost of the reactants, short reaction times and excellent yields.
- Eshghi, Hossein,Hosseini, Mosayyeb
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experimental part
p. 636 - 638
(2009/05/11)
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- Use of ethyl β-(4-hydroxyphinyl)-α-cyanoacrylate in the synthesis of carbazone, thiazole and imidazolidin-2-thione derivatives
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CONDENSATION of ethyl β-(4-hydroxyphenyl)-α-cyanoacrylate with thiosemicarbazide gave the 4-hydroxybenzaldehyde thiosemicarbazone (3). Treatment of 3 with acetic anhydride, 4-substituted phenacyl bromide and ethyl chloroacetate yielded the corresponding N-acetyl derivative (4), thiazol derivative (5) and 3-substituted 4-oxo-imidazolidin-2-thione (6). Compound 6 reacted with benzyl chloride, methyl acrylate, phenyl- diazonium chloride and hydrazine hydrate to give 1-substituted imidazo-lidine-2-thione derivatives (7,8,9) and 1,2-bis (4-hydroxy-benzal-dehyde)-hydrazone (10). Treatment of 6 with acetic anhydride and 4-hydroxybenzaldehyde afforded the corresponding N-acetyl derivatives (11) and 5-substitued-imidazolidin-2-thione (12). The mass spectral fragmentation patterns of some compounds are described.
- Mahmoud
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experimental part
p. 287 - 302
(2009/09/08)
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- The catalytic olefination reaction of aldehydes and ketones with CBr 3CF3
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The new approach of catalytic olefination reaction (COR) has been used to convert aromatic and aliphatic aldehydes and ketones to 2-bromo-3,3,3- trifluoroprop-1-enes by the treatment of corresponding hydrazones with CBr 3CF3 under copper(I) catalysis conditions. The reaction proceeds stereoselectively, the target alkenes were obtained in good yields.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 907 - 913
(2007/10/03)
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- A novel approach to 2-chloro-2-fluorostyrenes
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A new general catalytic olefination reaction (COR) of aromatic and heteroaromatic aldehydes and ketones was applied to synthesise 2-chloro-2-fluorostyrenes. The two-stage procedure includes the transformation of carbonyl compounds into hydrazones followed by treatment with CFCl3 mediated by copper catalysis. Trichlorofluoromethane was used as a chlorofluoromethylene transfer reagent. The reaction proceeds stereoselectively and the target alkenes were obtained in high yield. A proposed mechanism for the reaction is discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Nenajdenko, Valentine G.,Shastin, Alexey V.,Korotchenko, Vasily N.,Varseev, Georgy N.,Balenkova, Elisabeth S.
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p. 302 - 308
(2007/10/03)
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- Solid-state reactivity of the hydrazine-hydroquinone complex
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The solid-state reactivities of the hydrazine-hydroquinone 1:1 complex and of hydrazine hydrochloride with solid aldehydes, ketones, carboxylic acids, thiohydantoin and 4-nitrophenyl isothiocyanate were investigated. Only the hydrazine complex provides quantitative additions, condensations, ring openings and ring closures. The solid-state mechanisms were investigated by atomic force microscopy (AFM) and the far-reaching anisotropic molecular movements are correlated with the crystal packing, both on the hydrazine complex surface and on the surface of two benzaldehydes. The hydrazine moves into the aldehyde crystals for chemical reaction without melting. Characteristic surface features are created by the common phase rebuilding and phase transformation on both the hydrazine-donating and -accepting crystals. Copyright
- Kaupp, Gerd,Schmeyers, Jens
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p. 388 - 394
(2007/10/03)
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- Chemistry of diazocarbonyl compounds. IV. Synthesis and chemical properties of triphenylphosphoranylidenhydrazones of alkyl oxocarboxylates
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Alkyl 3-diazo-2-oxopropanoates react with triphenylphosphine to form corresponding triphenylphosphoranylidenehydrazones. The latter form symmetrical azines with aromatic aldehydes. Ethyl (Z)-5-aryl-5-hydroxy-2-diazo-3-oxo-4-pentenoates under the action of
- Zalesov,Vyaznikova,Andreichikov
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p. 705 - 709
(2007/10/03)
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