Synthesis, structures, and properties of lantern-type dinuclear ruthenium(II,III) complexes cis-[Ru2{3,5-(CF3)2-pf}2(O2CMe)2Cl] and [Ru2{3,5-(CF3)2-pf}3(O2CMe)Cl], 3,5-(CF3)2-pf− = N,N′-bis[3,5-bis(trifluoromethyl)phenyl]formamidinate anion

•Ru2II,III complexes with formamidinate and acetate bridges were synthesized.•Lantern-type dinuclear structures were determined by X-ray crystallography.•Magnetic susceptibility data showed three unpaired electrons in the Ru2 cores.•1H and 19F NMR spectra showed cis-(2:2) and (3:1) arrangements of bridging ligands.

Lantern-type dinuclear complexes, cis-[Ru2{3,5-(CF3)2-pf}2(O2CMe)2Cl] and [Ru2{3,5-(CF3)2-pf}3(O2CMe)Cl] (3,5-(CF3)2-pf− = N,N′-bis[3,5-bis(trifluoromethyl)phenyl]formamidinate anion), were prepared and characterized. The cis-(2:2) and (3:1) arrangements of the formamidinate and acetate bridging ligands around the Ru25+ core were confirmed by the X-ray crystal analysis as well as 1H and 19F NMR spectra (measured at 25 °C in CD2Cl2), where paramagnetic shifts were observed for the signals due to the unpaired electrons in the dinuclear core. Variable-temperature magnetic moments (2–300 K) showed the existence of three unpaired electrons in the dinuclear units with the large D values (60 cm−1 for the cis-(2:2) Ru25+ complex and 50 cm−1 for the (3:1) Ru25+ complex). The electronic state with S = 3/2 was also ascertained by the EPR spectra measured in solid at 4 K and in frozen toluene/dichloromethane solution at 15 K, absorption spectra in dichloromethane and cyclic voltammograms (CVs) in THF using tetra-n-butyl ammonium perchlorate (TBAP) as electrolyte.

Graphical abstractThe paramagnetic lantern-type dinuclear complexes, cis-[Ru2{3,5-(CF3)2-pf}2(O2CMe)2Cl] and [Ru2{3,5-(CF3)2-pf}3(O2CMe)Cl], were prepared and characterized. The cis-(2:2) and (3:1) arrangements of the bridging ligands were confirmed by X-ray crystal structures and 1H and 19F NMR spectra (in CD2Cl2 at 25 °C).Figure optionsDownload full-size imageDownload as PowerPoint slide