CpRu Complexes Containing Water Soluble Phosphane PTA and Natural Purines Adenine, Guanine and Theophylline: Synthesis, Characterization, and Antiproliferative Properties

Abstract

Complexes [RuCp(Adeninate‐κN9)(PTA)2] (1), [RuCp(Guaninate‐κN9)(PTA)2] (2), [RuCp(Theophyllinate‐κN7)(PTA)2] (3), [RuCp(Adeninate‐κN9)(PPh3)(PTA)] (4), [RuCp(Guaninate‐κN9)(PPh3)(PTA)] (5) and [RuCp(Theophyllinate‐κN7)(PPh3)(PTA)] (6) were synthesized and characterized by NMR spectroscopy, elemental analysis and FT‐IR (PTA = 1,3,5‐triaza‐7‐phosphaadamantane). Crystal structures of 1·H2O·3EtOH, 3·CH3COCH3 and 4·H2O were also determined by single‐crystal X‐ray diffraction. The antiproliferative activities of the complexes against cisplatin‐sensitive T2 and cisplatin‐resistant SKOV3 cell lines have also been evaluated. Theoretical studies were preformed to elucidate how the adeninate ligand is coordinated to the metal.

Synthesis of IrIII Hydrido Complexes by Oxidative Addition of Halogenated Theophylline and Adenine Derivatives

“…The resonance for the C6 carbon atom was detected in the 13 C­{ 1 H} NMR spectra at δ = 162.2 ppm for [ 1 ] and at δ = 162.4 ppm for [ 2 ]. These resonances are shifted downfield by about 5 ppm relative to the C6O resonance for free theophylline or of complexes bearing a monodentate N7-deprotonated theophylline ligand. − We assume that the C6O coordination to the iridium atom lowers the electron density at the oxygen atom, thereby causing the observed downfield shift of the C6 resonance. The 31 P NMR spectra of [ 1 ] and [ 2 ] feature, as expected, each two resonances for the chemically different phosphorus atoms.…”

Investigating the reactivity of neutral water-soluble Ru(ii)–PTA carbonyls towards the model imine ligands pyridine and 2,2′-bipyridine

“…5b, [36][37][38][39][40] Only recently the group of Romerosa described a series of neutral Ru(II)-PTA half-sandwich compounds that bear a natural purine bound through the N7 or N9 of the imidazolic ring. 41 When trans,trans,trans-[RuCl 2 (CO)(OH 2 )(PTA) 2 ] (1) was treated with a slight excess of pyridine in water at room temperature, the yellow complex trans,trans,trans-[RuCl 2 (CO)(py)(PTA) 2 ] (7) was selectively obtained upon evaporation of the solvent (Scheme 1) and fully characterized by ESI-MS, NMR, and IR spectroscopies (ESI †). Thus, pyridine easily and selectively replaced the labile aqua ligand with retention of the geometry.…”

Stereoisomeric Control in [RuCl2(PTA)2(2L)] Complexes (2L=2py or bpy): From Theoretical Calculations to a 2+2 Metallacycle of Pyridylporphyrins

“…Whereas there are very few examples of Ru(II)‐PTA coordination compounds in the literature with monodentate pyridine or azole ligands, [40] i. e. not included in polydentate moieties, [12,44–49] those with chelating diimine ligands are relatively more abundant. Stereoisomeric derivatives such as mer ‐ and fac ‐[Ru(bpy)Cl(PTA) 3 ](PF 6 ), and cis ‐ and trans ‐[Ru(bpy) 2 (PTA) 2 ](PF 6 ) 2 were prepared by us and by Romerosa and co‐workers [36,50–52] .…”