title: Polyhedral metallaheteroborane chemistry. Synthesis, spectroscopy, structure and dynamics of eleven-vertex {RhNB(9)} and {PtCB(9)} metallaheteroboranes.
abstract: Reaction between [RhCl(PPh(3))(3)] and the [nido-6-NB(9)H(11)](-) anion in CH(2)Cl(2) yields orange eleven-vertex [8,8-(PPh(3))(2)-nido-8,7-RhNB(9)H(11)]. Reaction of the [nido-6-CB(9)H(12)](-) anion with [cis-PtCl(2)(PMe(2)Ph)(2)] in methanol affords yellow eleven-vertex [9-(OMe)-8,8-(PMe(2)Ph)(2)-nido-8,7-PtCB(9)H(10)], which is also formed from the reaction of MeOH with [8,8-(PPh(3))(2)-nido-8,7-PtCB(9)H(10)]. Both compounds have been characterised by single-crystal X-ray diffraction analysis and examined by NMR spectroscopy and have structures based on eleven-vertex nido-type geometries, with the metal centre and the heteroatoms in the adjacent (8)- and (7)-positions on the pentagonal open face. The metal-to-heteroborane bonding sphere of is fluxional, with a DeltaG(double dagger) value of 48.4 kJ mol(-1). DFT calculations on the model compounds [8,8-(PH(3))(2)-nido-8,7-RhNB(9)H(11)] and [8,8-(PH(3))(2)-nido-8,7-RhSB(9)H(10)] have been carried out to define the fluxional process and the intermediates involved.
authors.affiliation: School of Chemistry, University of Leeds, Leeds, UKLS2 9JT.
authors.forename: Ramón
authors.initials: R
authors.lastname: Macías
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bould
authors.forename: Josef
authors.initials: J
authors.lastname: Holub
authors.forename: John D
authors.initials: JD
authors.lastname: Kennedy
authors.forename: Bohumil
authors.initials: B
authors.lastname: Stíbr
authors.forename: Mark
authors.initials: M
authors.lastname: Thornton-Pett