81195-82-6Relevant articles and documents
The Chemistry of Isomers of Icosaborane(26), B20H26: Synthesis and Nuclear Magnetic Resonance Study of Various Isomers of Platinahenicosaboranes and Diplatinadocosaboranes, and X-Ray Crystal and Molecular Structures of 7,7-Bis(dimethylphenylphosphine)-nido-7-platinaundecaborane and 4-...
Boocock, Simon K.,Greenwood, Norman N.,Kennedy, John D.,McDonald, Walter S.,Staves, John
, p. 2573 - 2584 (2007/10/02)
An improved synthesis of the known compound has been developed by deprotonation of B10H14 with NNN'N'-tetramethylnaphthalene-1,8-diamine followed by treatment with cis-.This reaction has been applied to the 2,2',2,6', and 1,5'isomers of (B10H13)2 to prepare various isomeric platinahenicosaborane clusters which differ either in the position of the conjuncto-linkage or the site of the platinum atom in the cluster.Appropriate modification of the reaction stoicheiometry in the case of 2,2'-(B10H13)2 led to the isolation of cisoid and transoid diplatinadocosaboranes 2>.The X-ray crystal structure of showed it to contain a platinaundecaborane cluster in which the tetrahapto B10H12 group is twisted by ca. 20 deg with respect to the PtP2 plane.Similarly, the molecular structure of the isomer of 4-B10H11-B10H13)> obtained from 2,2'-(B10H13)2 is distorted by a twist of ca. 8 deg.A detailed n.m.r. study of a number of these clusters has been made, using the resonances of 1H, 11B, 31P, and 195Pt.In addition to permitting structural assignments, the data reveal a novel mutual pseudo-rotation of the η4-B10H11X group (X=H or B10H13) and the (PMe2Ph)2 grouping about the central Pt atom.For the two sets of 1H- methyl resonances at 100 MHz coalesce at 71.5 deg C with an implied activation energy ΔG% of 79 +/- 5 kJ mol-1 for the fluxional process.Similar activation energies were deduced for the various isomers of .