Cationic η5-cyclopentadienylpalladium(II) complexes. Compounds of type [Pd(η5-C5H5)L2]PF6 containing tertiary phosphines, arsines, and stibines. Crystal and molecular structure of [Pd(η5-C5H5)(SbPh3)2]PF6·CH2Cl2

Abstract

The complexes [Pd(η⁵-C₅H₅)L₂]PF₆[where L = PMe₂Ph, PPh₃, AsMe₂Ph, AsPh₃, or SbPh₃ and L₂=(SS)-, (RR,SS)-, (RS)-C₆H₄(PMePh)₂-o or (SS)-, (RR,SS)-, (RS)-C₆H₄(AsMePh)₂-o] have been prepared in high yield from the appropriate complexes [PdCl₂L₂] and cyclopentadiene in Me₂CO in the presence of AgPFe₆, or with AgNO₃ followed by metathesis with NH₄PF₆. The brightly coloured compounds conduct as uni-univalent electrolytes in Me₂CO and CH₂Cl₂ and have spectroscopic properties consistent with η⁵ co-ordination of the cyclopentadienyl moiety in solution. The molecular structure of [Pd(η⁵-C₅H₅)(SbPh₃)₂]PF₆·CH₂Cl₂ has been determined by a single-crystal X-ray analysis. The crystals are monoclinic, space group P2₁/c with a= 12.506(6), b= 19.002(7), c= 18.575(5)Å, β= 106.53(3)°, and Z= 4. The structure was solved by heavy-atom methods at 295(1) K and refined by least-squares methods to R= 0.051 for 4 384 observed reflections. The arrangement of the two antimony atoms and the centre of the cyclopentadienyl ring about the palladium atom is approximately trigonal. The co-ordinated cyclopentadienyl moiety shows no significant deviations from planarity.