Half-sandwich complexes of ruthenium, osmium, rhodium and iridium with dl-methionine or S-methyl-l-cysteine: a solid state and solution equilibrium study

Abstract

Half-sandwich type platinum metal ions form stable 1 : 1 complexes with dl-methionine and S-methyl-l-cysteine resulting in diastereomers that epimerize at the S donor.

Ruthenium Arene Complexes with α‐Aminoacidato Ligands: New Insights into Transfer Hydrogenation Reactions and Cytotoxic Behaviour

“…The possible intramolecular replacement of water by a donor atom within the amino acidate side chain, as it has been ascertained in the case of 4 (Scheme ), might retard reactions with biological substrates but might also represent an alternative mechanism of inhibition. In this regard, it should be mentioned that compounds [Ru(η 6 ‐ p ‐cymene)(κ 2 N , O,S ‐aa)]X (aa = l / dl ‐methionine, X = Cl, NO 3 ), containing a tridentate α‐amino acidato ligand, were found to be ineffective against A2780 cancer cells . On the other hand, the absence of cytotoxicity has been observed here even when a triphenylphosphine co‐ligand is introduced, affording a relatively inert cationic complex ( 9 + ).…”

“…Addition of AgNO 3 to the 4 /D 2 O solution resulted in disappearance of the Ru–Cl species in the 1 H spectrum. Two of the remaining three sets of resonances were assigned to the aquo complex ( 4 W , two diastereomers) and the other one, featuring an unusually high‐field shifted resonance for the methylene group (Δ δ H = –0.5 ppm vs. 4 ), can be tentatively associated to the tridentate chelate compound [Ru(η 6 ‐ p ‐cymene)(κ 3 N , O , O ′‐ l ‐serinato)] + ( 4 T ; Scheme b) as a single diastereomer . Remarkably, previous studies on the interaction of the [Ru(η 6 ‐ p ‐cymene)] 2+ moiety with l ‐/ dl ‐serine in aqueous solution indicated the involvement of the amino acid side‐chain in the coordination , …”

“…Two out of three Ru species that were suppressed by NaCl addition and were preserved after treatment with AgNO 3 were identified as 4 W (two diastereomers). The remaining species could be identified as [Ru(η 6 ‐ p ‐cymene)(κ 3 N , O , O ′‐ l ‐serinato)] + ( 4 T , single diastereomer) . 4 (major diastereomer)/ 4 (minor diastereomer)/ 4 W (diastereomer‐1)/ 4 W (diastereomer‐2)/ 4 T molar ratio = 17:10:24:24:25.…”

[(η6-p-cymene)Ru(H2O)3]2+ binding capability of aminohydroxamates — A solution and solid state study

“…Earlier studies mostly dealt with the design, synthesis, characterization and biological test of these [(η 6 -arene)Ru(XY)Z] type (arene = benzene(derivative), XY = chelating, Z = monodentate ligand) complexes. [6][7][8][9][10] Recent years research focusing on their solution behaviour or the interaction with various high [11][12][13][14][15][16][17] or low molecular mass [18][19][20][21][22][23][24][25][26][27][28][29] biomolecules is also in progress.…”

Speciation of Metal Complexes of Medicinal Interest: Relationship between Solution Equilibria and Pharmaceutical Properties

“…While Cys was found to replace the ligand en and a sulfur-bridged dimeric complex was formed with 50% abundance [12]. donor set was proved [90]. The stability of these complexes is much higher compared to that of the analogous species formed with Ser that binds via (N,COO -,O -) donor set, due to the stronger preference for the sulfur donor atoms (see Fig.…”