A family of edge-sharing bi-octahedral diruthenium(III,III) compounds containing Ru-Ru single bonds.

From paddlewheel starting reactants Ru 2 (R'CO 2 ) 4 + , a family of edge-sharing bi-octahedral (ESBO) diruthenium(III,III) compounds has been prepared, formulated as Ru 2 (μ-O 2 CR') 2 (μ-OR) 2 (η-L) 2 (1-10) [R' = CH 3 , R = CH 3 , L = acac (1), tfac (2); R' = CH 3 , R = CH 2 CH 3 , L = hfac (3); R' = CH 2 CH 3 , R = CH 3 , L = acac (4), tfac (5); R' = CH 2 CH 3 , R = CH 2 CH 3 , L = hfac (6); R' = CH 2 Cl, R = CH 3 , L = tfac (7); R' = CH 2 Cl, R = CH 2 CH 3 , L = hfac (8); R' = C 6 H 5 , R = CH 3 , L = tfac (9); and R' = H, R = CH 3 , L = acac (10); here, acac, tfac and hfac represent acetylacetone, trifluoroacetylacetone and hexafluoroacetylacetone, respectively]. Compounds 1-10 have a similar ESBO coordination geometry of the Ru(μ-O 2 CR') 2 (μ-OR) 2 Ru core with a Ru-Ru center chelated and bridged by two μ-O 2 CR' and two μ-OR in a trans manner, and each Ru center is also coordinated with a η 2 -L bidentate ligand. The Ru-Ru distances fall in the range of 2.4560(9)-2.4771(4) Å. The investigation of the electronic spectra and vibrational frequencies as well as theoretical studies with density functional theory (DFT) reveal that compounds 1-10 are ESBO bimetallic species of d 5 -d 5 valence electron counts showing a σ 2 π 2 δ 2 δ* 2 π* 2 electronic configuration. Varying -CH 3 to -CF 3 groups on the η 2 -L bidentate ligands coordinating to the Ru(μ-O 2 CR') 2 (μ-OR) 2 Ru core, and according to Raman spectrum measurements combined with theoretical calculations, the intense bands of compounds 1-10 appearing at ∼345 cm -1 in the small-wavenumber region can be assigned to the stretching of the Ru-Ru single bond.