Treatment of the known half-sandwich complexes of the type [(η 6-C 6 H 6)RuCl 2 (P(OR) 3)] (R = Me or Ph) with SnCl 2 yielded three new half-sandwich ruthenium complexes (C1-C3): [(η 6-C 6 H 6)RuCl(SnCl 3)(P(OMe) 3)] (C1), [(η 6-C 6 H 6)RuCl(SnCl 3)(P(OPh) 3)] (C2) and the bis-stannyl complex [(η 6-C 6 H 6)Ru(SnCl 3) 2 (P(OMe) 3)] (C3) by facile insertion of SnCl 2 into the Ru-Cl bonds. Treatment of the known complexes [(η 6-C 6 H 6)RuCl(SnCl 3)(PPh 3)] and [(η 6-C 6 H 6)RuCl 2 (PPh 3)] with 4-dimethylaminopyridine (DAMP) and ammonium tetrafluoroborate afforded the complex salts: [(η 6-C 6 H 6)Ru(SnCl 3)(PPh 3)(DAMP)] + BF 4 − (C4) and [(η 6-C 6 H 6)RuCl(PPh 3)(DAMP)] + BF 4 − (C5) respectively. Complexes C1-C5 have been fully characterized by spectroscopic means (IR, UV-vis, multinuclear NMR, ESI-MS) and their thermal behaviour elucidated by thermal gravimetric analysis (TGA). Structural characterization by single crystal X-ray crystallography of the novel complex C2 and [(η 6-C 6 H 6)RuCl 2 (P(OPh) 3)], the latter having escaped elucidation by this method, is also reported. Finally, the cytotoxicity of the complexes was determined on the A2780 (human ovarian cancer), A2780cisR (human ovarian cis-platin-resistant cancer), and the HEK293 (human embryonic kidney) cell lines and discussed, and an attempt is made to elucidate the effect of the stannyl ligand on cytotoxicity.

Keep your distance! A simple and effective protocol for connecting macrocycle polymers creates a new and versatile class of highly stable single-site catalytic materials.

The electrochemical reduction of CO2 (CO2RR) is a sustainable alternative for producing fuels and chemicals, although the production of highly desired hydrocarbons is still a challenge due to the higher overpotential requirement in combination with the competitive hydrogen evolution reaction (HER). Tailoring the electrolyte composition is a possible strategy to favor the CO2RR over the HER. In this work we studied the solvent effect on the CO2RR on a nanostructured Cu electrode in acetonitrile solvent with different amounts of water. Similar to what has been observed for aqueous media, our online gas chromatography results showed that CO2RR in acetonitrile solvent is also structure-dependent, since nanocube-covered copper (CuNC) was the only surface (in comparison to polycrystalline Cu) capable of producing a detectable amount of ethylene (10% FE), provided there is enough water present in the electrolyte (>500 mM). In situ Fourier Transform Infrared (FTIR) spectroscopy showed that in acetonitrile solvent the presence of CO2 strongly inhibits HER by driving away water from the interface. CO is by far the main product of CO2RR in acetonitrile (>85% Faradaic efficiency), but adsorbed CO is not detected. This suggests that in acetonitrile media CO adsorption is inhibited compared to aqueous media. Remarkably, the addition of water to acetonitrile has little quantitative and almost no qualitative effect on the activity and selectivity of the CO2RR. This indicates that water is not strongly involved in the rate-determining step of the CO2RR in acetonitrile. Only at the highest water concentrations and at the CuNC surface, the CO coverage becomes high enough that a small amount of C2+ product is formed.