Title

Thermal and potentiometric studies for complexes of Zr and Hf with some barbituric acid derivatives

Document Type

Conference Proceeding

Abstract

The complexes of Barbital (Bal), Thiobarbituric acid thione (TBA), Thiobarbituric acid thiol (2-TBA), 2-Thiouracil (TU) with Zr (IV) and Hf (IV) were prepared. The structures and mode of bonding were characterized by elemental analysis, IR and electronic spectroscopy. Thermal analyses of the prepared complexes were done by DTA, TG, DSC techniques. The thermodynamic parameters were evaluated. The change of entropy values, ΔS#, for all the complexes lie within the range -0.267,-0.299 KjK-1 mol-1. The thermal processes proceed in complicated mechanisms with ordered transition states. In general, the complexes dissociated after losing small molecules such as H2O, Cl2 and CO. The decomposition is usually ended by the metal moiety. The DSC technique explained the effect of temperature on physical properties of some complexes. The glass transition phase doesn`t appear in all the complexes, while the crystallization temperature (Tc) was 780C-322.120C. Potentiometric titration studies calculated the dissociation constants of the ligands, the stability constants of the complexes and the distribution of species at different pH values.

Publication Date

12-31-2020

Faculty

Faculty of Applied Health Sciences Technology

Subject Area

Physical Sciences, General Materials Science, General Engineering

Indexed in Scopus

yes

DOI

https://doi.org/10.1088/1757-899X/975/1/012015

Volume

975

Keywords

Acid derivatives, Barbituric, Complexes, DSC, DTA, Hf, IR, Potentiometric titration, TGA, Zr

ISSN

17578981

eISSN

1757899X

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