Institution: | aInstitute of General and Inorganic Chemistry, Russian Academy of Science, 31, Leninsky Pr., GSP-1, 119991 Moscow, Russia bMoscow State Academy of Fine Chemical Technology, 86, Vernadskogo Pr., 119571 Moscow, Russia cInstituto de Investigaciones Quimicas, Consejo Superior de Investigaciones Cientificas-Universidad de Sevilla, Avda. Americo Vespucio, 49, 41092 Sevilla, Spain |
Abstract: | The first examples of binary palladium(II) derivatives of unsaturated carboxylic acids are reported. It was found that the interaction of Pd3(μ-OAc)6 with the ,β-unsaturated 1-methylcrotonic (tiglic) and crotonic acids leads to the corresponding carboxylates of composition Pd3μ-O2CC(R′) = CHMe]6, where R′ = Me (1) or H (2). The new compounds have been characterized by elemental analysis, solid and solution IR, 1H and 13C NMR, and ESI mass spectrometry. The crystal structure of 1 has been determined. This molecule displays a central Pd3 cyclic core with Pd–Pd distances of 3.093–3.171 Å. Each Pd–Pd bond is bridged by a pair of carboxylate ligands, one above and the other below the Pd3 plane, providing a square planar coordination for each Pd atom in an approximate D3h overall symmetry arrangement. Solution spectroscopic data show that the bridging η1:η1:μ2 interaction of the carboxylates of 1 and 2 is readily displaced, with a change of the ligand to the terminal (η1) coordination mode. |