Versatility and trends in the interaction between Pd(ii) and peptide hydroxamic acids

Abstract

The interaction between di- and tripeptide hydroxamic acids and Pd(ii) (as a Pt(ii) model but with faster ligand exchange reactions) was studied in aqueous solution in the presence of chloride ions by pH-potentiometric and NMR methods revealing ligand-dependent competition between the coordinative and hydrolytic processes.

Trends and Exceptions in the Interaction of Hydroxamic Acid Derivatives of Common Di- and Tripeptides with Some 3d and 4d Metal Ions in Aqueous Solution

“…The ligands AlaAlaNHOH, AlaAlaN(Me)OH, AlaGlyGlyNHOH, and AlaGlyGlyN(Me)OH were synthesized as previously described [19,20,21]. The purity and the exact concentration of the ligand stock solutions were determined by pH-potentiometry using the Gran’s method [33].…”

“…Significantly, increased interest toward the metal complexes of aminohydroxamic acids have been realised following the first publication on a pentanuclear β-alaninehydroxamate-based Cu(II)-containing metallacrown complex both in solution and in the solid state [14] and the discovery of numerous and diverse possibilities of applications of such compounds [15,16]. Peptide hydroxamic acids, however, despite the special interest in them e.g., to develop substrate-based metalloenzyme inhibitors [5], have very rarely been involved in solution studies [17,18,19,20,21]. Moreover, most of the results relate to complexes with 3d 5–10 transition metal ions and only a few with 4d metals [21].…”

“…Peptide hydroxamic acids, however, despite the special interest in them e.g., to develop substrate-based metalloenzyme inhibitors [5], have very rarely been involved in solution studies [17,18,19,20,21]. Moreover, most of the results relate to complexes with 3d 5–10 transition metal ions and only a few with 4d metals [21]. Following our solution equilibrium work done ca.…”

“…Out of the platinum group metals, only a recent publication from our lab discusses solution results on the rather complicated Pd(II)–AlaAlaNHOH, –AlaAlaN(Me)OH, –AlaGlyGlyNHOH, and –AlaGlyGlyN(Me)OH systems. In these systems, complexation and metal ion–induced hydrolytic and redox processes were found in a ligand-dependent extent [21]. No other metal from this group has previously been involved in investigations with peptide hydroxamic acids.…”

Selectivity of Benzyl Hydroxamic Acid in the Flotation of Ilmenite

“…Covalent bonds formed between Fe of ilmenite surface and the O of oleate. Due to the activation of Pb(OH) + , there were more adsorption sites of ilmenite for BHA (Meng et al, 2018;Ozsváth et al, 2019). And five-membered rings formed among lead species and BHA, which improved the selectivity of BHA.…”