Structural, magnetic, and 1H NMR spectral study on lantern-type cis- and trans-diruthenium(II,III) complexes with two formamidinato and two acetato bridges

Abstract Lantern-type dinuclear complexes, cis -[Ru 2 (4-Me-pf) 2 (O 2 CMe) 2 Cl] and trans -[Ru 2 (2,6-Et 2 -pf) 2 (O 2 CMe) 2 Cl] (4-Me-pf −  =  N , N ′-bis(4-methylphenyl)formamidinate ion and 2,6-Et 2 -pf −  =  N , N ′-bis(2,6-diethylphenyl)formamidinate ion), were prepared and characterized. The dinuclear structures with cis - and trans -arrangements of the bridging ligands were confirmed by the X-ray crystal structures as well as 1 H NMR spectra (298 K) in CD 2 Cl 2 , where the proton signals were observed at widely spread positions δ = − 80 to 25 ppm. Variable-temperature magnetic moments (2–300 K) showed the existence of three unpaired electrons in dinuclear units with large D values (65 cm − 1 for cis -Ru 2 II,III and 90 cm − 1 for trans -Ru 2 II,III ).