Open Journal of Applied Sciences, 2021, 11, 1-10 https://www.scirp.org/journal/ojapps ISSN Online: 2165-3925 ISSN Print: 2165-3917 DOI: 10.4236/ojapps.2021.111001 Jan. 11, 2021 1 Open Journal of Applied Sciences Metal Complexes with 8-Hydroxyquinoline: Synthesis and In Vitro Antimicrobial Activity Amira Cipurković 1 , Emir Horozić 2 , Snježana Marić 1 , Lejla Mekić 3 , Halid Junuzović 2 1 Faculty of Natural Sciences and Mathematics, University of Tuzla, Tuzla, Bosnia and Herzegovina 2 Faculty of Technology, University of Tuzla, Tuzla, Bosnia and Herzegovina 3 Faculty of Pharmacy, University of Tuzla, Tuzla, Bosnia and Herzegovina Abstract In this paper, three complexes with 8-hydroxyquinoline (8-HQ) were synthe- sized, their spectral analysis was performed and the antimicrobial effect was examined in vitro. The stoichiometric ratio of the complex was determined conductometrically and spectrophotometrically. FTIR and UV/VIS spectros- copy were used for structural characterization. Antimicrobial activity was ex- amined by diffusion technique on selected gram-positive and gram-negative bacteria, and C. albicans. Square planar and octahedral geometry complexes were synthesized by mixing in a molar ratio of 1:2 (M:L). Based on the spec- tral data, it is concluded that both oxygen and nitrogen atoms from 8-HQ are involved in the formation of the complex. The antimicrobial activity of the complexes is high, with zones of inhibition in the range of 15 - 28 mm. 8-HQ was shown to have a significantly higher ability to inhibit the growth of the tested microorganisms. Keywords 8-HQ, Metal Complex, Antimicrobial Activity, In Vitro Study 1. Introduction 8-Hydroxyquinoline (8-HQ), also known as oxine or 8-quinolinol, is an alkaloid which exists in plants of Asteraceae and Euphorbiaceae families [1] [2]. It is a mo- noprotic, bidentate agent (Figure 1) that consists of two donor atoms, oxygen and nitrogen [2]. The 8-HQ molecule acts as potent metal ion chelator, due to its oxygen and nitrogen atoms [3]. Many studies on 8-hydroxyquinoline complexes were con- ducted to date. After metal binding, 8-HQ changes its fluorescence. Construction of How to cite this paper: Cipurković, A., Horozić, E., Marić, S., Mekić, L. and Junuzović, H. (2021) Metal Complexes with 8-Hydroxyquinoline: Synthesis and In Vitro Antimicrobial Activity. Open Journal of Applied Sciences, 11, 1-10. https://doi.org/10.4236/ojapps.2021.111001 Received: December 1, 2020 Accepted: January 8, 2021 Published: January 11, 2021 Copyright © 2021 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access