title: Effect of pnictogen ligand substitution on a tripalladium ditropylium core.
abstract: A combination of multinuclei NMR, UV-vis spectroscopy, and single crystal X-ray diffraction was used to characterize a new series of tripalladium ditropylium sandwich complexes [Pd(3)Tr(2)(E)(3)][BF(4)](2) (E = PPh(3), AsPh(3), and SbPh(3) and PEt(3)). Ligand substitution leads to a systematic shift of the (1)H and (13)C NMR tropylium resonances and is correlated with the electron donating properties of the substituent group. Replacement of the ligand increases the palladium-pnictogen bond length in the order P < As < Sb; however, this only slightly alters the internal Pd-Pd bond lengths, supporting the hypothesis that there are only weak Pd-Pd bonding interactions.
authors.affiliation: Department of Chemistry and Biochemistry, Northern Arizona University, Flagstaff, Arizona 86011-5698, USA.
authors.forename: Dominic C
authors.initials: DC
authors.lastname: Babbini
authors.forename: Frank L
authors.initials: FL
authors.lastname: Mulligan
authors.forename: Hannah R
authors.initials: HR
authors.lastname: Schulhauser
authors.forename: Tara C
authors.initials: TC
authors.lastname: Sweigart
authors.forename: Gary S
authors.initials: GS
authors.lastname: Nichol
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Hurst