title: An unusal case of facile non-degenerate P-C bond making and breaking.
abstract: Oxidation of Li/X phosphinidenoid complex 2, obtained via selective deprotonation from the P-H precursor 1, with [Ph(3)C]BF(4) led to the formation of two P-F substituted diorganophosphane complexes 6,7; the latter tautomer 7 formed via H-shift from 6. In contrast, oxidation of 2 with [(p-Tol)(3)C]BF(4) led to three major and one minor intermediates at low temperature, which we tentatively assign to two pairs of P-C atropisomers 10 a,a' and 10 c,c' and which differ by the relative orientations of their CH(SiMe(3))(2) and W(CO)(5) groups. Conversion of all isomers led finally to complex 11 having a ligand with a long P-C bond to the central trityl* carbon atom, firmly established by single-crystal X-ray analysis. DFT calculations at the B3LYP/def2-TZVPP//BP86/def2-TZVP level of theory on real molecular entities revealed the structures of the in situ formed combined singlet diradicals (4+5 and 5+9) and the nature of intermediates on the way to the final product, complex 11. Remarkable is that all isomers of 11 possess relative energies in the narrow energy regime of about 20 kcal  mol(-1). A preliminary study revealed that complex 11 undergoes selective P-C bond cleavage at 75 °C in toluene solution.
authors.affiliation: Institut für Anorganische Chemie der Rheinischen Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany.
authors.forename: Vitaly
authors.initials: V
authors.lastname: Nesterov
authors.forename: Aysel
authors.initials: A
authors.lastname: Özbolat-Schön
authors.forename: Gregor
authors.initials: G
authors.lastname: Schnakenburg
authors.forename: Lili
authors.initials: L
authors.lastname: Shi
authors.forename: Asli
authors.initials: A
authors.lastname: Cangönül
authors.forename: Maurice
authors.initials: M
authors.lastname: van Gastel
authors.forename: Frank
authors.initials: F
authors.lastname: Neese
authors.forename: Rainer
authors.initials: R
authors.lastname: Streubel
mesh_terms: D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D004583:Electrons; D005609:Free Radicals / Q000737:chemistry*; D007536:Isomerism; D008094:Lithium / Q000737:chemistry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010720:Phosphines / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D010720:Phosphines; D008094:Lithium