We report structure−activity relationships for organometallic RuII complexes of the type [(η6-arene)Ru(XY)Cl]Z, where XY is an N,N- (diamine), N,O- (e.g., amino acidate), or O,O- β-diketonate) chelating ligand, arene ranges from benzene derivatives to fused polycyclic hydrocarbons, and Z usually PF6. The X-ray structures 13 are reported. All have characteristic “piano-stool” geometry. most active toward A2780 human ovarian cancer cells contained = ethylenediamine (en) extended arenes....

Bioorganometallic chemistry is a rapidly developing area of research. In recent years organometallic compounds have provided rich platform for the design effective catalysts, e.g. olefin metathesis and transfer hydrogenation. Electronic steric effects are used to control both thermodynamics kinetics ligand substitution redox reactions metal ions, especially RuII. Can similar features be incorporated into targeted drugs? Such complexes offer potential novel mechanisms drug action through...

The low-spin 5d6 IrIII organometallic half-sandwich complexes [(η5-Cpx)Ir(XY)Cl]0/+, Cpx = Cp*, tetramethyl(phenyl)cyclopentadienyl (Cpxph), or tetramethyl(biphenyl)cyclopentadienyl (Cpxbiph), XY 1,10-phenanthroline (4−6), 2,2′-bipyridine (7−9), ethylenediamine (10 and 11), picolinate (12−14), hydrolyze rapidly. Complexes with N,N-chelating ligands readily form adducts 9-ethylguanine but not 9-ethyladenine; bind to both purines. Cytotoxic potency toward A2780 human ovarian cancer cells...

Abstract Platinum complexes are the most widely used anticancer drugs; however, new generations of agents needed. The organoiridium(III) complex [(η 5 ‐Cp xbiph )Ir(phpy)(Cl)] ( 1‐Cl ), which contains π‐bonded biphenyltetramethylcyclopentadienyl (Cp ) and C^N‐chelated phenylpyridine (phpy) ligands, undergoes rapid hydrolysis chlorido ligand. In contrast, pyridine )Ir(phpy)(py)] + 1‐py aquates slowly, is more potent (in nanomolar amounts) than both cisplatin towards a wide range cancer cells....

Organometallic complexes offer chemistry that is not accessible to purely organic molecules and, hence, potentially new mechanisms of drug action. We show here the presence both an iodido ligand and a sigma-donor/pi-acceptor phenylazopyridine confers remarkable inertness toward substitution on half-sandwich "piano-stool" ruthenium arene [(eta(6)-arene)Ru(azpy)I](+) (where = p-cymene or biphenyl, azpy N,N-dimethylphenyl- hydroxyphenyl-azopyridine) in aqueous solution. Surprisingly, despite...

Organometallic complexes are effective hydrogenation catalysts for organic reactions. For example, Noyori-type ruthenium catalyse reduction of ketones by transfer hydride from formate. Here we show that such catalytic reactions can be achieved in cancer cells, offering a new strategy the design safe metal-based anticancer drugs. The activity ruthenium(II) sulfonamido ethyleneamine towards human ovarian cells is enhanced up to 50 × presence low non-toxic doses extent conversion coenzyme...

Organometallic compounds offer broad scope for the design of therapeutic agents, but this avenue has yet to be widely explored. A key concept in anticancer complexes is optimization chemical reactivity allow facile attack on target site (e.g., DNA) avoid other sites associated with unwanted side effects. Here, we consider how result can achieved monofunctional “piano-stool” ruthenium(II) arene type [(η 6 -arene)Ru(ethylenediamine)(X)] n + . potentially important activation mechanism...

The Os(II) arene ethylenediamine (en) complexes [(eta(6)-biphenyl)Os(en)Cl][Z], Z = BPh(4) (4) and BF(4) (5), are inactive toward A2780 ovarian cancer cells despite 4 being isostructural with an active Ru(II) analogue, 4R. Hydrolysis of 5 occurred 40 times more slowly than aqua adduct 5A has a low pK(a) (6.3) compared to that [(eta(6)-biphenyl)Ru(en)(OH(2))](2+) (7.7) is therefore largely in the hydroxo form at physiological pH. rate extent reaction 9-ethylguanine were also less those We...

A photoactivated ruthenium(II) arene complex has been conjugated to two receptor-binding peptides, a dicarba analogue of octreotide and the Arg-Gly-Asp (RGD) tripeptide. These peptides can act as "tumor-targeting devices" since their receptors are overexpressed on membranes tumor cells. Both ruthenium-peptide conjugates stable in aqueous solution dark, but upon irradiation with visible light, pyridyl-derivatized were selectively photodissociated from ruthenium complex, inferred by UV-vis NMR...

Artificial enzymes: Half-sandwich arene ruthenium(II) and cyclopentadienyl iridium(III) complexes containing N,N-chelated ligands can use NADH as a source of hydride for the reduction ketones (see picture). Moreover, phenanthroline derivatives at micromolar concentrations are robust catalysts production H2 from in water raise NAD+/NADH ratio cancer cells. Detailed facts importance to specialist readers published "Supporting Information". Such documents peer-reviewed, but not copy-edited or...

Density functional calculations show that aquation of [Os(eta6-arene)(XY)Cl]n+ complexes is more facile for in which XY=an anionic O,O-chelated ligand compared to a neutral N,N-chelated ligand, and the mechanism dissociative character. The XY=maltolato (mal) [M(eta6-p-cym)(mal)Cl] complexes, p-cym=p-cymene, M=OsII (1) RuII (2), were synthesised X-ray crystal structures 1 22 H2O determined. Their hydrolysis rates rapid (too fast follow by NMR spectroscopy). aqua adduct OsII complex was 1.6...

Replacing the N,N-chelating ligand 2,2′-bipyridine (bpy) in IrIII pentamethylcyclopentadienyl (Cp*) complex [(η5-C5Me5)Ir(bpy)Cl]+ (1) with C,N-chelating 2-phenylpyridine (phpy) to give [(η5-C5Me5)Ir(phpy)Cl] (2) switches on cytotoxicity toward A2780 human ovarian cancer cells (IC50 values of >100 μM for 1 and 10.8 2). Ir–Cl hydrolysis is rapid both complexes (hydrolysis equilibrium reached <5 min at 278 K). Complex 2 forms adducts 9-ethylguanine (9-EtG) 9-methyladenine (9-MeA), but...

Organometallic IrIII cyclopentadienyl complexes [(η5-Cpx)Ir(C∧N)Cl] {Cpx = Cp*, C∧N 2-(p-tolyl)pyridine (1), 2-phenylquinoline (2), 2-(2,4-difluorophenyl)pyridine (3), Cpx tetramethyl(phenyl)cyclopentadienyl (Cpxph), 2-phenylpyridine (4), and tetramethyl(biphenyl)cyclopentadienyl (Cpxbiph), (5)} have been synthesized characterized. The X-ray crystal structures of 2 5 determined show typical “piano-stool” geometry. All the hydrolyzed rapidly in aqueous solution (<5 min) even at 278 K. pKa...

The synthesis and characterization of a family piano-stool RuII arene complexes the type [(η6-arene)Ru(N,N′)(L)][PF6]2, where is p-cymene (p-cym), hexamethylbenzene (hmb), or indane (ind), N,N′ 2,2′-bipyrimidine (bpm), 1,10-phenanthroline (phen), 1,10-phenanthroline-5,6-dione (phendio), 4,7-diphenyl-1,10-phenanthroline (bathophen), L pyridine (Py), 4-methylpyridine (4-MePy), 4-methoxypyridine (4-MeOPy), 4,4′-bipyridine (4,4′-bpy), 4-phenylpyridine (4-PhPy), 4-benzylpyridine (4-BzPy),...

The synthesis of nanoparticles conjugates caffeic acid-modified chitosan with ruthenium arene complexes is described.

We report the synthesis and characterization of eight half-sandwich cyclopentadienyl Ir

Strongly luminescent iridium(III) complexes, [Ir(C,N)2 (S,S)]+ (1) and (O,O)] (2), containing C,N (phenylquinoline), O,O (diketonate), or S,S (dithione) chelating ligands, have been characterized by X-ray crystallography DFT calculations. Their long phosphorescence lifetimes in living cancer cells give rise to high quantum yields for the generation of 1 O2 , with large 2-photon absorption cross-sections. 2 is nontoxic cells, but potently cytotoxic upon brief irradiation low doses visible...

One electron at a time: Half-sandwich organometallic cyclopentadienyl–IrIII complexes containing N,N-chelated ligands can catalyze the reduction of quinones (Q), such as vitamin K3, to semiquinones (Q.−) by coenzyme NADH (see picture). DFT calculations suggest that mechanism involves hydride transfer followed two one-electron transfers and unusual IrII oxidation state key transient intermediate.

We report the synthesis, characterization, and antiproliferative activity of 15 iridium(III) half-sandwich complexes type [(η

A photoactivatable dopamine-conjugated platinum(IV) anticancer complex (Pt-DA) has been incorporated into G-quadruplex G4K+ borate hydrogels by using ester linkages (Pt-G4K+B hydrogel). These were characterized 11B NMR, attenuated total reflection Fourier transform infrared spectroscopy, circular dichroism, scanning electron microscopy and transmission microscopy. Microscopy investigations revealed the transformation of an extended fiber assembly discrete flakes after incorporation Pt-DA....