Can a meso-type dinuclear complex be chiral?: dinuclear -diketonato Ru(III) complexesElectronic supplementary information (ESI) available: The results of chromatographic resolution of [Ru(III)(acac)2(S- or R-dabe)Ru(III)(acac)2)] and [Ru(III)(acac)2(tbet)Ru(III)(acac)2)]; mass spectra and 1H NMR of [Ru(acac)2(CH3(CN)2]PF6, dabeH2 and tbetH2; 1H NMR data of the isomers of [Ru(III)(acac)2(S- or R-dabe)Ru(III)(acac)2] and [Ru(III)(acac)2(tbet)Ru(III)(acac)2]; chiral chromatographic resolution of [R

Dinuclear Ru(III) complexes, [Ru(III)(acac) 2 (dabe)Ru(III)(acac) 2 ] (acacH = acetylacetone; dabeH 2 = 1, 2-diacetyl-1,2-dibenzoylethane) and [Ru(III)(acac) 2 (tbet)Ru(III)(acac) 2 ] (tbetH 2 = 1,1,2,2-tetrabenzoylethane) were synthesized by reacting [Ru(acac) 2 (CH 3 CN) 2 ]PF 6 with dabeH 2 and tbetH 2 respectively, in toluene. The X-ray structural analysis of a meso-type dinuclear Ru(III) complex, [Ru(III)(acac) 2 (dabe)Ru(III)(acac) 2 ], showed that the bridging part became chiral due to the orthogonal twisting of two non-symmetrical -diketonato moieties. To confirm this conclusion, the complex was resolved chromatographically to provide a pair of optical antipodes. Such chirality in the bridging part was not generated for [Ru(III)(acac) 2 (tbet)Ru(III)(acac) 2 ], because the -diketonato moieties in tbet 2 are symmetrical. X-ray structural analysis shows that the bridging part of -[Ru(III)(acac) 2 (dabe)Ru(III)(acac) 2 ] (dabe = 1,2-diacetyl-1,2-dibenzoylethanato) becomes chiral due to the orthogonal twisting of two non-symmetrical -diketonato moieties.