Design and modulation of selectivity toward vanadium(V) and uranium(VI) ions: coordination properties and affinity of hydroxylamino-triazine siderophores

Amoiridis, A., Papanikolaou, M., Vlasiou, M., Bandeira, N. A. G., Miras, H. N. , Kabanos, T. and Keramidas, A. (2023) Design and modulation of selectivity toward vanadium(V) and uranium(VI) ions: coordination properties and affinity of hydroxylamino-triazine siderophores. Inorganic Chemistry, 62(49), pp. 19971-19985. (doi: 10.1021/acs.inorgchem.3c02678) (PMID:38018803) (PMCID:PMC10716903)

Abstract

Based on the strong binding and high selectivity properties of 2,6-bis[hydroxy(methyl)amino]-4-morpholino-1,3,5-triazine (H2bihyat) for [UVIO2]2+, novel binucleating ligands (BLs) N,N′,N″,N‴-((1,4-phenylenebis(oxy))bis(1,3,5-triazine-6,2,4-triyl))tetrakis(N-methylhydroxylamine) (H4qtn), N1,N4-bis(4,6-bis(hydroxy(methyl)amino)-1,3,5-triazin-2-yl)benzene-1,4-diamine (H4pdl), and N1,N2-bis(4,6-bis(hydroxy(methyl)amino)-1,3,5-triazin-2-yl)ethane-1,2-diamine (H4enl) were synthesized. Binuclear complexes formed by coordination of hard metal ions with H4qtn are thermodynamically more stable than their mononuclear analogues with H2bihyat due to the increase in entropy accompanying the formation of more chelate rings. Reaction of either H4qtn or H4pdl or H4enl with [UVIO2]2+ and [VVO2]+ resulted in the isolation of the binuclear complexes [(UVIO2)2(μ-qtn)(H2O)4] (1), [(VVO2)2(μ-qtn)][PPh4]2[PPh4] (2), [(UVIO2)2(μ-pdl)(H2O)2(MeOH)2] (3), [(VVO2)2(μ-pdl)][PPh4]2 (4), [(UVIO2)2(μ-enl)(H2O)4] (5), and [(VVO2)2(μ-enl)][PPh4]2 (6). The binuclear complexes 1–6 were characterized by single-crystal X-ray diffraction analysis in solid state and by NMR and ESI-MS in solution. The comparison of the coordination ability of the BLs with either pyridine-2,6-dicarboxylic acid (H2dipic) or H2bihyat or CO32– toward [UVIO2]2+ and [VVO2]+ was investigated by NMR and UV–vis spectroscopies and DFT theoretical calculations, revealing a superior performance of BLs. The selectivity of the BLs for [UVIO2]2+ over [VVO2]+ is decreased compared to that of H2bihyat but increases considerably at pH > 9 values. Formation of the mixed-metal binuclear species [UVIO2(μ-O)VVO2] influences the selectivity and dynamics of the reaction of H4qtn for [UVIO2]2+ and [VVO2]+ in aqueous solution. The results of this study provide crucial information for the ligand design and the development of stronger and more selective systems.

• Item Type: Articles
• Additional Information: The research work was funded by the European Regional Development Fund and the Republic of Cyprus through the Research and Innovation Foundation (project: EXCELLENCE/0421/0520).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Moiras, Professor Haralampos
• Authors: Amoiridis, A., Papanikolaou, M., Vlasiou, M., Bandeira, N. A. G., Miras, H. N., Kabanos, T., and Keramidas, A.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Inorganic Chemistry
• Publisher: American Chemical Society
• ISSN: 0020-1669
• ISSN (Online): 1520-510X
• Published Online: 29 November 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Inorganic Chemistry 62(49):19971-19985
• Publisher Policy: Reproduced under a Creative Commons license