Physico-chemical study of complexing processes in AlCl3-L-H2O  system where L – DPA, centralite, DNT, DBP

This work presents a method of powder components’ interaction, containing a trivalent nitrogen and other atoms with an undivided electron pair (UEP) with the aqueous solutions of complexing extragents. In the role of the latter, an aqueous solution of aluminium chloride was studied. Diphenylamine (DPA), centralite 1 (or diethyldiphenylurea), dinitrotoluene (DNT) and dibutylphthalate (DBP) were considered as organic components. A donor-acceptor mechanism of the reagents’ interaction is proposed, in which a section of a molecule of an organic component of powder, containing an element atom with UEP, acts as a donor of the electron pair; an aluminium ion with free p- and d-orbitals acts as an acceptor. It is the presence of both types of free orbitals that allows Al3+ ion to increase its coordination up to 6 in complex compounds, which it forms. The complex compounds (CCs) of aluminium chloride and powder components with the trivalent nitrogen atom and with other atoms with UEP were obtained in an aqueous medium. CCs were studied by the methods of the physico-chemical analysis such as conductance-measuring and titrimetric methods (complexation and agrentometric titration), chromatographic methods (thin-layer chromatography and gas-liquid chromate-graphy) and spectral methods (IR- and UV-spectrometry). The fragments of functional groups, involving in the formation of the intermolecular bonds such as amino group in DPA molecule, carbonyl group in centralite 1 molecule, nitro group in DNT molecule, ester group in DBP molecule and π-system of aromatic ring in all molecules of the considered organic components of powder, were revealed. It is found that a reason for an increase in a solubility of organic compounds of powder in water is the formation of complex compounds such as “double salts”. The optimal conditions for obtaining CCs such as “double salts” were determined. Later, this fact was applied for an extraction of these components from a powder composition.

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Quantum chemical study of physical characteristics of Co- and Ni-faujasites

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19821282 ◽

1982 ◽

Vol 47 (5) ◽

pp. 1282-1289 ◽

Cited By ~ 2

Author(s):

Stanislav Beran

Keyword(s):

Electron Donor ◽

Quantum Chemical Study ◽

Chemical Characterization ◽

Chemical Study ◽

Hydroxyl Groups ◽

Strong Electron ◽

Charge Densities ◽

Physico Chemical ◽

Donor Acceptor ◽

Trivalent Cations

The CNDO/2 method was used for a physico-chemical characterization of faujasite zeolites, modelled by T6O6(OH)12 clusters containing Ni+, Ni2+, Ni(OH)+, Co2+, Co3+, Co(OH)+ cations localized in the SII and SI' cationic positions. It is shown that the cations are bound preferentially to the oxygen atoms of the zeolite skeleton by a strong electron donor-acceptor bond. As the consequence of the bond formation, the electron charge is significantly shifted from a skeleton to the cation. The charge densities calculated on the cations (Ni+ ~ 0.3, Ni2+ ~ 0.35, Co2+ ~ 0.4, Co3+ ~ 1.1 respectively) show that with uni- and bivalent cations the positive charge is in main part compensated by donation of electrons from the skeleton, while with trivalent cations the compensation is only partial. The Ni+ cation possesses significant electron donor properties whereas the Co3+ cation has a strong electron acceptor character. For both cations bivalency appears to be the most stable valent state. Both studied cations show great affinity to hydratation, however, their corresponding hydroxyl adducts - the Ni(OH)+ and Co(OH)+ cations exhibit substantially less acid properties, compared with the hydroxyl groups of the skeleton.

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