Edita Bjelić, Mersiha Suljkanović, Jasmin Suljagić, Azra Kovačević

Faculty of Technology, University of Tuzla, Univerzitetska 8, 75 000 Tuzla
Bosnia and Herzegovina, edita.nurkovic@untz.ba

Faculty of Natural Sciences and Mathematics, University of Tuzla, Univerzitetska 4, 75 000
Tuzla, Bosnia and Herzegovina

ORIGINAL SCIENTIFIC PAPER

ISSN 2637-2150
e-ISSN 2637-2614
UDK 615.33:546.650
DOI: 10.7251/STED0220001B

Paper received: 20.10.2020.
Paper accepted: 20.11.2020.
Published: 30.11.2020.
http://stedj-univerzitetpim.com

Corresponding Author: 
Edita Bjelić, Faculty of Technology, University of Tuzla, Univerzitetska 8, 75 000 Tuzla, Bosnia and Herzegovina, edita.nurkovic@untz.ba

ABSTRACT

The conductometric study of ligand structure influence on the Pb(II) complexation with crown ethers in different solvents has been investigated. In this paper, the complexation reaction of macrocyclic ligand, 18-crown-6 (18C6), dibenzo-18-crown-6 (DB18C6), and Pb(II) cation was studied in different solvents: dichloromethane (DCM) and 1,2- dichloroethane (1,2-DCE). The effects of surfactant structure (Triton X-100 and Triton X-45) on the conductivity of the Pb(II) complex with 18-crown-6 and dibenzo-18-crown-6 ether have been investigated. The conductance data showed that the stoichiometry of the complexes in most cases is 1:1(ML). It is also demonstrated that the influence of crown ethers is deeply affected by the organic solvent used. In the solvents studied, the stability of the resulting complexes showed higher stability in dichloromethane comparing with 1,2- dichloroethane. Macrocyclic ligand 18-crown-6 showed more suitable for complexation of Pb(II) ions compared to dibenzo-18-crown-6. Adding a surfactant affected the higher absolute values of the conductivity of systems, but not the change in the stoichiometric ratio between a metal ion and macrocyclic ligand.

Keywords: crown ethers, Pb(II), conductometry, 18-crown-6