Perturbation of OH groups in decationated Y-zeolites by physically adsorbed gases. Part 2.—Heats of adsorption

1971 ◽  
Vol 67 (0) ◽  
pp. 1821-1829 ◽  
Author(s):  
J. M. André ◽  
J. J. Fripiat
Keyword(s):  
Y Zeolites ◽  
Oh Groups ◽  
Heats Of Adsorption

Perturbation of OH groups in decationated Y-zeolites by physically adsorbed gases

1967 ◽  
Vol 63 (0) ◽  
pp. 461-475 ◽  
Author(s):  
J. L. White ◽  
A. N. Jelli ◽  
J. M. André ◽  
J. J. Fripiat
Keyword(s):  
Y Zeolites ◽  
Oh Groups

Isosteric heats of adsorption of xenon in silver-exchanged Y zeolites

Zeolites ◽  
1993 ◽  
Vol 13 (6) ◽  
pp. 427-429 ◽  
Author(s):  
J. Watermann ◽  
B. Boddenberg
Keyword(s):  
Y Zeolites ◽  
Heats Of Adsorption

OH groups in hydrothermally treated dealuminated Y zeolites

Zeolites ◽  
1989 ◽  
Vol 9 (1) ◽  
pp. 74-77 ◽  
Author(s):  
V. Patzelová ◽  
E. Drahorádová ◽  
Z. Tvarůẑková ◽  
U. Lohse
Keyword(s):  
Y Zeolites ◽  
Oh Groups

Experimental and Theoretical Investigations of Complex Formation of Substituted Phenylazo-Derivatives of Methylphloroglucinol

2016 ◽  
Vol 12 (8) ◽  
pp. 295-300
Author(s):  
Olga Kovalchukova ◽  
Amangdam A.T. ◽  
Strashnova S.B. ◽  
Strashnov P.V. ◽  
Romashkina E.P. ◽  
...  
Keyword(s):  
Complex Formation ◽  
Organic Ligand ◽  
Spectrophotometric Titration ◽  
Organic Ligands ◽  
Oh Groups ◽  
Tautomeric Forms ◽  
Theoretical Investigations ◽  
Derivatives Of ◽  
Theoretical Results ◽  
Titration Technique

Using spectrophotometric titration technique, the processes of complex formation of some phenylazo-derivatives of methylphloroglucinol (MPG) containing hydroxo-, nitro- and nitroso-substituents were studied. The spectral criteria of neutral and ionized forms of the organic ligands in their different tautomeric forms were determined.It was detected that the complex formation is accompanied by formation of one or two chelate cycles which involve azo- or nitroso-fragments and neighboring OH-groups of the organic ligands. Different types of coordination lead to different changes in the electronic absorption spectra.The DFT-B3LYP modeling of a Ni(II) complex of α-hydroxyphenylazo MPG established the most probable coordination mode of the organic ligand: tridentate chelating dianion, distorted square coordination of Ni-cations including one water molecule.  The theoretical results are in a good accordance with the experimental data.

Statistical Analysis of the Relationship Between Antioxidant Activity and the Structure of Flavonoid Compounds

2019 ◽  
Vol 70 (9) ◽  
pp. 3103-3107 ◽  
Author(s):  
Ioana Glevitzky ◽  
Gabriela Alina Dumitrel ◽  
Mirel Glevitzky ◽  
Bianca Pasca ◽  
Pavel Otrisal ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Basic Structure ◽  
Oh Groups ◽  
Flavonoid Compounds ◽  
Chi Squared ◽  
Potential Link ◽  
Van Der Waals Surface ◽  
The Relationship ◽  
Phenolic Oh Groups

Using different methods of statistics, this paper aims to highlight the potential link between the antioxidant activity of flavonoids and the corresponding molecular descriptors. By calculating the descriptors (van der Waals surface (A), molar volume (V), partition coefficient (LogP), refractivity (R), polarizability (a), forming heat (Hformation), hydration energy (Ehidr), the dipole moment (mt)), together with antioxidant activities (RSA) calculated or taken from the literature, number of phenolic -OH groups and the presence (2) or absence (1) of C2=C3 double bond) for 29 flavonoid compounds and by intercorrelation between the studied parameters, the link between the number of phenolic groups grafted to the basic structure of flavonoids and their antioxidant activity was confirmed. Simultaneously, by using the chi-squared test and the intercorrelations matrix, a satisfactorily correlation coefficient (r2=0.5678; r=0.7536) between the structure of the flavonoids and their activity was obtained, fact that confirms the correlation of the antioxidant activity with the number of -OH phenolic groups.

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