10.6084/m9.figshare.1568467.v4
Ivan Jakovljevic
Ivan
Jakovljevic
Djordje Petrovic
Djordje
Petrovic
Ljubinka Joksovic
Ljubinka
Joksovic
Ivan Lazarevic
Ivan
Lazarevic
Milena Jelikic-Stankov
Milena
Jelikic-Stankov
Predrag Djurdjevic
Predrag
Djurdjevic
Complex formation equilibria between aluminum(III), gadolinium(III) and yttrium(III) ions and some fluoroquinolone ligands. Potentiometric and spectroscopic study
Taylor & Francis Group
2015
gadolinium
potentiometric
spectroscopic measurements
Complex formation equilibria
concentration levels
spectroscopic study Complex formation equilibria
fluoroquinolone antibacterials moxifloxacin
stability constants
MS data
yttrium
Hyperquad 2006 program
coordination bond
cm
cl
nmr
spectroscopic methods
aid
metal ion properties
HypSpec 2014
Fluorimetric data
fluoroquinolone ligands
levofloxacin
complex
2015-11-26 22:06:52
Journal contribution
https://tandf.figshare.com/articles/journal_contribution/Complex_formation_equilibria_between_aluminum_III_gadolinium_III_and_yttrium_III_ions_and_some_fluoroquinolone_ligands_Potentiometric_and_spectroscopic_study/1568467
<div><p>Complex formation equilibria of aluminum(III), gadolinium(III), and yttrium(III) ions with the fluoroquinolone antibacterials moxifloxacin, ofloxacin, fleroxacin, lomefloxacin, levofloxacin, and ciprofloxacin were studied in aqueous solution by potentiometric and spectroscopic methods. The identity and stability of metal–fluoroquinolone complexes were determined by analyzing potentiometric titration curves (310 K, <i>μ</i> = 0.15 M NaCl, pH range = 2–11, <i>C</i><sub>L</sub>/<i>C</i><sub>M</sub> = 1 : 1 to 3 : 1, <i>C</i><sub>M</sub> = 1.0 mM) with the aid of Hyperquad2006 program. The main species formed in the system may be formulated as M<sub>p</sub>H<sub>q</sub>L<sub>r</sub> (p = 1, q = −2 to 2, r = 1–3, L = fluoroquinolone anion, logarithm of overall stability constant, log <i>β</i><sub>p,q,r</sub> = in the range <i>ca.</i> −10 to 45). The stability of complexes is mostly influenced by metal ion properties (ionization potential, ionic radius) indicating partial ionic character of the coordination bond. The complexes were also characterized by spectroscopic measurements: spectrofluorimetry, <sup>1</sup>H-NMR, and ESI-MS. Fluorimetric data were evaluated with the aid of HypSpec2014 and indicated the formation of ML<sub>r</sub> (r = 1–3) complexes with cumulative conditional stability constants significantly lower than the thermodynamic ones. NMR and MS data corroborate potentiometrically determined speciation. Calculated plasma mobilizing capacity of the ligands generally follows the order levofloxacin > moxifloxacin > ciprofloxacin at concentration levels of the ligands higher or equal to <i>ca.</i> 10<sup>−4</sup> M.</p></div>