scholarly journals Synthesis of 12-Substituted 1-Carba-closo-dodecaborate Anions and First Hyperpolarizability of the 12-C7H6+-CB11H11Ylide [J. Am. Chem. Soc.1999,121, 3122−3126].

2000 ◽  
Vol 122 (45) ◽  
pp. 11274-11274 ◽  
Author(s):  
Bohumír Grüner ◽  
Zbyněk Janoušek ◽  
Benjamin T. King ◽  
Jeffrey N. Woodford ◽  
C. H. Wang ◽  
...  
Keyword(s):  
First Hyperpolarizability ◽  
Substituted 1

Synthesis of 12-Substituted 1-Carba-closo-dodecaborate Anions and First Hyperpolarizability of the 12-C7H6+-CB11H11-Ylide

1999 ◽  
Vol 121 (13) ◽  
pp. 3122-3126 ◽  
Author(s):  
Bohumír Grüner ◽  
Zbyněk Janoušek ◽  
Benjamin T. King ◽  
Jeffrey N. Woodford ◽  
C. H. Wang ◽  
...  
Keyword(s):  
First Hyperpolarizability ◽  
Substituted 1

Synthesis, characterization and biological activities of 1,3,4-oxadiazole derivatives of nalidixic acid and their copper complexes

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Nalidixic Acid ◽  
Copper Complexes ◽  
Biological Activities ◽  
Bidentate Coordination ◽  
Antibacterial And Antifungal Activities ◽  
Elemental Analyses ◽  
Oxadiazole Derivatives ◽  
Antibacterial And Antifungal ◽  
Derivatives Of ◽  
Substituted 1

A series of novel 1, 3, 4-oxadiazole analogues was synthesized from cyclization of hydrazones of substituted 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carbohydrazides were prepared from nalidixic acid. The structures of synthesized oxadiazole derivatives and their copper complexes were elucidated on the basis of FTIR, elemental analyses, 1H-NMR and atomic absorption spectral analysis. It was observed from spectral data that metal ligand ratio was 1:1 in all copper complexes and they were bidentate, coordination was found to be done through oxygen of 4-oxo group and nitrogen of oxadiazole ring. The synthesized compounds were further evaluated with biological activities and compared with parent hydrazones. Copper complexes possess antibacterial and antifungal activities better than the oxadiazoles while they have better antioxidant activity then copper complexes. Parent hydrazones were better in all biological activities than synthesized oxadiazoles.

Full Kinetics and a Mechanism Investigation for the Generation of 4- Substituted 1, 4-Dihydropyridine Derivatives in the Presence of Green Catalyst and Aqueous Medium: Experimental Procedure

2020 ◽  
Vol 17 ◽  
Author(s):  
Sayyed Mostafa Habibi-Khorassani ◽  
Mehdi Shahraki ◽  
Sadegh Talaiefar
Keyword(s):  
Reaction Mechanism ◽  
Reaction Centre ◽  
Green Catalyst ◽  
Experimental Procedure ◽  
Dominant Mechanism ◽  
Rate Determining Step ◽  
12 Steps ◽  
Reaction Constant ◽  
Substituted 1 ◽  
Dihydropyridine Derivatives

Aims and Objective: The main objective of the kinetic investigation of the reaction among ethyl acetoacetate 1, ammoniumacetat 2, dimedone 3 and diverse substitutions of benzaldehyde 4-X, (X= H, NO2, CN, CF3, Cl, CH (CH3)2, CH3, OCH3, OCH3, and OH) for the generation of 4-substituted 1, 4-dihydropyridine derivatives (product 5) was the recognition of the most realistic reaction mechanism. The layout of the reaction mechanism studied kinetically by means of the UV-visible spectrophotometry approach. Materials and Methods: Among the various mechanisms, only mechanism1 (path1) involving 12 steps was recognized as a dominant mechanism (path1). Herein, the reaction between reactants 1 and 2 (kobs= 814.04 M-1 .min-1 ) and also compound 3 and 4-H (kobs= 151.18 M-1 .min-1 ) were the logical possibilities for the first and second fast steps (step1 and step2, respectively). Amongst the remaining steps, only step9 of the dominant mechanism (path1) had substituent groups (X) near the reaction centre that could be directly resonated with it. Results and Discussion: Para electron-withdrawing or donating groups on the compound 4-X increases the rate of the reaction 4 times more or decreases 8.7 times less than the benzaldehyde alone. So, this step is sensitive for monitoring any small or huge changes in the reaction rate. For this reason, step9 is the rate-determining step of the reaction mechanism (path1). Conclusion: The recent result is the agreement with the Hammett description with an excellent dual substituent factor (r = 0.990) and positive value of reaction constant (ρ = +0.9502) which confirmed both the resonance and inductive effects “altogether” contributed on the reaction centre of step9 in the dominant mechanism (path1).

Extraction of hafnium by means of some substituted 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-ones

1981 ◽  
Vol 46 (8) ◽  
pp. 1901-1905 ◽  
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola
Keyword(s):  
Ionic Strength ◽  
Aqueous Phase ◽  
Dissociation Constants ◽  
Parent Substance ◽  
Benzoyl Group ◽  
Extraction Constants ◽  
Extraction Parameters ◽  
Substituted 1

Distribution between aqueous phase and benzene or chloroform was studied for 1-phenyl-3-methyl-4-benzoylpyrazol-5-ones with 2-chloro, 4-methoxy, 3-nitro, and 4-nitro substitution in the benzoyl group (ionic strength of the aqueous phase 0.1) and for hafnium in their presence (ionic strength 2.0). The distribution and dissociation constants of the reagents and the extraction constants of their hafnium complexes were determined. Hafnium was found to be extracted as the HfA4 species. The extraction parameters of the derivatives in question do not differ substantially from those of the parent substance.

Ab initio Hartree-Fock Investigation of π-Conjugated Compounds Presenting Large βv/βe Ratio: Merocyanines

1998 ◽  
Vol 63 (9) ◽  
pp. 1295-1308 ◽  
Author(s):  
Benoît Champagne ◽  
Thierry Legrand ◽  
Eric A. Perpete ◽  
Olivier Quinet ◽  
Jean-Marie André
Keyword(s):  
Ab Initio ◽  
First Hyperpolarizability ◽  
Conjugated Molecules ◽  
Hartree Fock ◽  
Experimental Discovery ◽  
Conjugated Compounds ◽  
Molecular Frame

CHF/6-311G* calculations of the first electronic and vibrational hyperpolarizabilities reveal that merocyanines present a substantial βv/βe ratio under their quinonoid nonpolar form. It originates from a large vibrational first hyperpolarizability whereas its electronic counterpart is small for this class of push-pull π-conjugated molecules. The transition from the quinonoid to the aromatic configuration is accompanied by an increase of βe and a decrease of the βv/βe ratio as well as by a ≈ 180° rotation in the plane of the molecule of βe and βv with respect to the molecular frame. Our results support the recent experimental discovery that antiparallel aggregation of aromatic and quinonoid forms of merocyanine is energetically favoured and that their first hyperpolarizabilities, which combine constructively, present both electronic and non purely electronic origins.

Sterically Crowded Heterocycles. III. A General Approach to Imidazo[1,2-a]pyridines by Ferricyanide Oxidation of Quaternary Pyridinium Salts

1996 ◽  
Vol 61 (1) ◽  
pp. 126-138 ◽  
Author(s):  
Richard Kubík ◽  
Stanislav Böhm ◽  
Iveta Ruppertová ◽  
Josef Kuthan
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Ferricyanide ◽  
Pyridinium Salts ◽  
Oxidizing Agents ◽  
Quaternary Pyridinium Salts ◽  
Substituted 1

Substituted 1-(pyridin-2-yl)-2,4,6-triphenylpyridinium perchlorates 1b-1e were converted with potassium ferricyanide and potassium hydroxide to sterically crowded 2-phenyl-3-[(Z)-1,3-diphenyl-3-oxopropenyl]imidazo[1,2-a]pyridines 2b-2e accompanied by minor isomeric 2-benzoyl-3,5-diphenyl-1-(pyridin-2-yl)pyrroles 3c-3e. 4-Phenyl-2,6-di(4-substituted phenyl)-1-(pyridin-2-yl)pyridinium salts 4a, 4b gave exclusively corresponding imidazo[1,2-a]pyridines 5a, 5b while the ferricyanide oxidation of 1-(5-iodo- and 5-cyanopyridin-2-yl)-2,4,6-triphenylpyridinium perchlorates 6a, 6b led to mixtures of major imidazo[1,2-a]pyridines 7a-7c and minor pyrroles 8a-8c. Some mechanistic aspects of the oxidation procedure are discussed in connection with a resistance of 2,6-diphenyl-1,3,5-trimethylpyridinium perchlorate (9c) towards the oxidizing agents.

Synthesis of β-D-Glucopyranosides of 6-Substituted 2-(Indol-3-yl)benzothiazoles

2005 ◽  
Vol 70 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Martin Humeník ◽  
Peter Kutschy ◽  
Katarína Valková ◽  
Branislav Horváth ◽  
Vladimír Kováčik ◽  
...  
Keyword(s):  
Potassium Ferricyanide ◽  
Substituted 1

A linear synthesis of substituted 1-(β-D-glucopyranosyl)benzocamalexins starting from indoline and penta-O-acetyl-β-D-glucopyranose was elaborated. Jacobson cyclization of corresponding 4-substituted peracetylated β-D-glucopyranosylindole-3-carbothioanilides employing potassium ferricyanide under basic conditions was a key synthetic step.

2,6-Dibromogallates as a new building block for controlling π-stacking, network formation and mirror symmetry breaking

2021 ◽  
Author(s):  
Ohjin Kwon ◽  
Xiaoqian Cai ◽  
Azhar Saeed ◽  
Feng Liu ◽  
Silvio Poppe ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Building Block ◽  
Mirror Symmetry ◽  
Network Formation ◽  
Network Structures ◽  
Π Stacking ◽  
Bicontinuous Cubic ◽  
Substituted 1 ◽  
End Group

Achiral multi-chain (polycatenar) compounds based on the 2,7-diphenyl substituted [1]benzothieno[3,2-b]benzothiophene (BTBT) unit and a 2,6-dibromo-3,4,5-trialkoxybenzoate end group lead to materials forming bicontinuous cubic liquid crystaline phases with helical network structures...

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