Reaction of the dimer [(η5-C5Me5)RhCl(μ2-Cl)]2 with 2 or 4 equiv of the water-soluble phosphine 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane (pta) affords [Rh(η5-C5Me5)(pta)Cl2] and [Rh(η5-C5Me5)(pta)2Cl]Cl, respectively. Both complexes have been characterized in solution by NMR spectroscopy and in the solid state by single-crystal X-ray diffraction, the latter as the chloride and BPh4 - salts. In addition, the rhodium(I) complexes [Rh(η5-C5Me5)(CO)(pta)] and [Rh(η5-C5H5)(pta)2] have been prepared from [Rh(η5-C5Me5)(CO)2] and [Rh(η5-C5H5)(PPh3)2], respectively, by reaction with pta. An in vitro evaluation of these compounds, together with [Os(η6-C10H14)(pta)Cl2] and the well-characterized antimetastasis drug [Ru(η6-C10H14)(pta)Cl2], RAPTA-C, was undertaken using HT29 colon carcinoma, A549 lung carcinoma, and T47D breast carcinoma cells. In the HT29 cell line, the two nearest congeners to [Ru(η6-C10H14)(pta)Cl2], viz., [Rh(η5-C5Me5)(pta)Cl2] and [Os(η6-C10H14)(pta)Cl2], demonstrated very similar cytotoxicity profiles. [Rh(η5-C5Me5)(pta)Cl2] proved significantly more cytotoxic in A549 cells and [Rh(η5-C5Me5)(pta)2Cl]Cl 3-fold more cytotoxic in T47D cells, both relative to RAPTA-C. These data suggest that the development of organometallic anticancer drugs based on the neighboring elements to ruthenium should not be overlooked.

No abstract

The reaction between H 2 O 2 and two water oxidation catalysts {[Cp*Ir(H 2 O) 3 ](NO 3 ) 2 (1, Cp* = pentamethylcyclopentadienyl) and [Cp*Ir(bzpy)(NO 3 )] (2, bzpy = 2-benzoylpyridine)} was studied by means of in situ 1D-and 2D-NMR experiments in order to elucidate if catalyst degradation proceeds through the initial functionalization of a quaternary carbon atom (C-attack) or by hydrogen abstraction (H-attack) of the Cp* -C-CH 3 moiety. It was shown that 1 underwent double functionalization of the -C-CH 3 moiety of Cp* leading to the formation of -C(OR)-CH 2 OR (R = H or OH) in [a]

It′s so easy: The readily available and highly water‐soluble [IrCl(Hedta)]Na complex is an efficient and robust catalyst for water oxidation to molecular oxygen. The reaction is driven by the reduction of Ce4+ to Ce3+. Its performances (TOF=6.8 min−1 and TON>12 000) are derived by UV/Vis spectroscopic, volumetric and electrochemical measurements, and compare favorably with those of the best catalysts reported so far.

No abstract

The first example of evolution of an iridanaphthalene into an indanone through an intermediate indenyl is reported, serving as a good example of starting material to obtain indanones. Two new iridanaphthalenes are obtained by intramolecular C−H activation of a phenyl ring of a carbene ligand in [IrCp*{C(OMe)CHCPh 2 }(L)]PF 6 (L = PPh 2 Me, PMe 3 ) complexes. It is demonstrated that these iridanaphthalene complexes can undergo a thermal reaction to give indenyl complexes and 3-phenylindanone.M etallacyclic aromatic compounds incorporating transition metals are a subject of great interest, since they display a behavior that includes properties from both aromatic organic and organometallic compounds. Although many metallabenzenes of osmium, iridium, platinum, and ruthenium are known, to the best of our knowledge only two metallanaphthalenes have been reported, one with osmium 1 and another with iridium. 2 The importance of this type of metal-organic functionality is emphasized by the fact that metal cyclopentadienyls can be formed from transitory metallabenzenes. 3 Analogously, an osmanaphthalene has been proposed as intermediate leading to an indenyl complex. 4 Recently, we have reported that the new (methoxy)-alkenylcarbeneiridium complex [IrCp*Cl{C(OMe)CH CPh 2 }(PPh 2 Me)]PF 6 (1a) reacts with amines to undergo the unexpected cleavage of the O−CH 3 bond instead of the usual aminolysis. 5 This peculiar behavior has prompted us to further explore the reactivity of these types of compounds. Here, we report that treatment of [IrCp*Cl{C(OMe)CHCPh 2 }-(L)]PF 6 (L = PPh 2 Me (1a), PMe 3 (1b)) with AgPF 6 gives high yields of the iridanaphthalene complexes [IrCp*{C(OMe)-CHC(o-C 6 H 4 )(Ph)}(L)]PF 6 (L = PPh 2 Me (2a), PMe 3 (2b)) through an intramolecular C−H activation of one of the phenyl rings of the carbene ligand (eq 1).The structures of both iridanaphthalene complexes have been confirmed by single-crystal X-ray diffraction (see the Supporting Information). Figure 1 shows the complex cation 2a. The iridium atom becomes part of a metallanaphthalene moiety and the metal coordination sphere is completed with a pentamethylcyclopentadienyl (Cp*) and a phosphane ligand.The NMR spectra support the solid-state structures of 2a,b (see the Supporting Information).Remarkably, the iridanaphthalene moiety is not stable and refluxing 2 in 1,2-dichloroethane or toluene for 24 h gives 3-phenylindanone (4) (eq 2). The same transformation occurs also at longer reaction times in dichloromethane at 35°C (eq 2).

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The self-aggregation tendency of RAPTA complexes {[Ru(η 6 -p-cymene){PTA(-R)}Cl 2 ]X, R ) H (1BPh 4 and 1PF 6 ) and Me (2BPh 4 and 2OTf), and [Ru(η 6 -p-cymene)(PTA) 2 Cl]X (3BPh 4 and 3BF 4 )} in acetone-d 6 was inVestigated by means of diffusion NMR spectroscopy. On increasing the concentration, the protonated species (1X) undergoes intercationic selfaggregation driVen by hydrogen bonding that leads to the formation of 1 2 2+ dications and a small amount of 1 2 X + ion triples.