Syntheses and Structure Study on 3,3aλ4,4-Trithia-1-azapentalenes and Their 3-Oxa Analogues

2003 ◽  
Vol 68 (7) ◽  
pp. 1243-1263 ◽  
Author(s):  
Richard Čmelík ◽  
Michal Čajan ◽  
Jaromír Marek ◽  
Pavel Pazdera
Keyword(s):  
Carboxylic Acid ◽  
Ir Spectroscopy ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Structure Study ◽  
X Ray ◽  
Phosphorus Pentasulfide

Reactions of nitrile, amide or ester of 5-amino-3-thioxo-3H-1,2-dithiole-4-carboxylic acid 1 with alkylation and acylation agents were studied. "Ionic" 1,2-dithiole amides 6 were formed in several ways. Treatment with phosphorus pentasulfide afforded the corresponding 3,3aλ4,4-trithia-1-azapentalenes 7. Structures of the synthesized heterocycles were studied using a combination of X-ray analysis, IR spectroscopy, and HF and DFT quantum-chemical calculations.

The Nature of Chemisorbed CO2 in Zeolite A

2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski
Keyword(s):  
Solid State ◽  
Ir Spectroscopy ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Surface Coverage ◽  
Gas Mixtures ◽  
Mas Nmr ◽  
Significant Fraction ◽  
Zeolite A

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.

scholarly journals Synthesis of Bis(Carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 (n = 0, 1) and Attempt of Synthesis of Gadolinium Bis(Dicarbollide)

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1321
Author(s):  
Yasunobu Asawa ◽  
Aleksandra V. Arsent’eva ◽  
Sergey A. Anufriev ◽  
Alexei A. Anisimov ◽  
Kyrill Yu. Suponitsky ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
X Ray Diffraction ◽  
Stable Conformation ◽  
Acyl Chlorides ◽  
X Ray ◽  
Cesium Fluoride ◽  
The Stability

Bis(carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 (n = 0, 1) were prepared by the reactions of the corresponding carboranyl acyl chlorides with ethylenediamine. Crystal molecular structure of 1,1′-μ-(CH2NH(O)C-1,2-C2B10H11)2 was determined by single crystal X-ray diffraction. Treatment of bis(carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 with ammonium or cesium fluoride results in partial deboronation of the ortho-carborane cages to the nido-carborane ones with formation of [7,7′(8′)-μ-(CH2NH(O)C(CH2)n-7,8-C2B9H11)2]2−. The attempted reaction of [7,7′(8′)-μ-(CH2NH(O)CCH2-7,8-C2B9H11)2]2− with GdCl3 in 1,2-dimethoxy- ethane did not give the expected metallacarborane. The stability of different conformations of Gd-containing metallacarboranes has been estimated by quantum-chemical calculations using [3,3-μ-DME-3,3′-Gd(1,2-C2B9H11)2]− as a model. It was found that in the most stable conformation the CH groups of the dicarbollide ligands are in anti,anti-orientation with respect to the DME ligand, while any rotation of the dicarbollide ligand reduces the stability of the system. This makes it possible to rationalize the design of carborane ligands for the synthesis of gadolinium metallacarboranes on their base.

Electrochemical aromatization of dihydroazines. Effect of chalcogenophosphoryl (CGP) substituents on anodic oxidation of 9-CGP-9,10-dihydroacridines

Synthesis ◽  
2021 ◽  
Author(s):  
Alexander Schepochkin ◽  
Oleg N. Chupakhin ◽  
Nadezhda Demina ◽  
Maxim Averkov ◽  
Tatyana Shimanovskaya ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Structural Analysis ◽  
Quantum Chemical Calculations ◽  
Anodic Oxidation ◽  
Quantum Chemical ◽  
X Ray

The effect of chalcogenophosphoryl fragments on the anodic oxidation of 9-chalcogenophosphoryl-9,10-dihydroacridines was studied in detail. The data of X-ray structural analysis, quantum chemical calculations and cyclic voltammetry obtained for these compounds provide an explanation of the observed features. The direct electrochemical phosphorylation of acridine was first carried out successfully.

Structure and Reactivity of [Mo3-μ3S-(μS2)3]4+Complexes. Quantum Chemical Calculations, X-ray Structural Characterization, and Raman Spectroscopic Measurements

1998 ◽  
Vol 37 (11) ◽  
pp. 2633-2644 ◽  
Author(s):  
María J. Mayor-López ◽  
Jacques Weber ◽  
Kaspar Hegetschweiler ◽  
Marc D. Meienberger ◽  
Felix Joho ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Structural Characterization ◽  
Quantum Chemical ◽  
Spectroscopic Measurements ◽  
X Ray ◽  
Raman Spectroscopic

Evaluation of Aspects Controlling Crystallization of Nitrofurantoin

2019 ◽  
Vol 800 ◽  
pp. 9-13
Author(s):  
Aija Trimdale ◽  
Agris Bērziņš
Keyword(s):  
Gibbs Energy ◽  
Quantum Chemical Calculations ◽  
Organic Solvents ◽  
Quantum Chemical ◽  
Polymer Additives ◽  
Factors Affecting ◽  
X Ray

Nitrofurantoin was crystallized from multiple mixtures of water and organic solvents with and without additives to try to find and identify factors affecting phase obtained in crystallization and provide possible information on crystallization control. Obtained crystals were identified with powder X-ray diffractometry. Crystallization control possibilities were evaluated by using polymer additives and crystallization additives, by also using quantum chemical calculations to investigate the association of nitrofurantoin and additive molecules and calculate Gibbs energy of association.

The synergy of different solid-state techniques to elucidate the supramolecular assembly of two 1H-benzotriazole polymorphs

2019 ◽  
Vol 21 (36) ◽  
pp. 19879-19889
Author(s):  
María Mar Quesada-Moreno ◽  
Juan Ramón Avilés-Moreno ◽  
Juan Jesús López-González ◽  
Fco. Javier Zúñiga ◽  
Dolores Santa María ◽  
...  
Keyword(s):  
Solid State ◽  
Quantum Chemical Calculations ◽  
Absolute Configuration ◽  
Quantum Chemical ◽  
Supramolecular Structure ◽  
Supramolecular Assembly ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Absolute

4aα (chiral) and 4aβ (achiral) polymorphs of 1H-benzotriazole are studied by X-ray crystallography, SSNMR, IR, Raman, VCD, and quantum chemical calculations. The absolute configuration of the supramolecular structure of 4aα polymorph is determined.

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