Chiral paramagnetic closo-ruthenacarboranes via phosphine-diphosphine displacement reaction of “three-bridge” exo-nido-ruthenacarboranes: Molecular Structure of (−)-[closo-3-Cl-3,3-{(Ph2PCHCH3)2CH2}-3,1,2-RuC2B9H11] and its ortho-cycloboronated derivati

The first 12-vertex chiral paramagnetic closo-ruthenacarboranes (−)-[closo-3-Cl-3,3-{(S,S)-BDPP}-3,1,2-RuC2B9H11] and its ortho-cycloboronated derivative (−)-[closo-3-Cl-3,3-{(S,S)-Ph2PCH(CH3)CH2CH(CH3)PPh- have been prepared in moderate yield by thermal replacement of PPh3 ligands in the [exo-nido-5,6,10-{Cl(Ph3P)2Ru}-5,6,10-μ-(H)3-10-H-7,8-C2B9H8] with the chiral diphosphine (2S,S)-(−)-2,4-bis-(diphenylphosphino)pentane (BDPP). Both odd-electron complexes were characterized by a combination of EPR and CD spectroscopy and by single-crystal X-ray diffraction analysis.