Heterometallic palladium-copper and palladium-nickel complexes with pivalate bridges

Reactions of (α-Pic)2Pd(OOCCMe3)2 (I) with dinuclear copper pivalate dihydrate and polymeric nickel bispivalate afforded the complexes (α-Pic)2Pd(μ-OOCCMe3)2Cu2(μ-OOCCMe3)4 (II) and Pd(μ- OOCCMe3)4Ni(α-Pic) (III), respectively, which were structurally characterized. The lantern dimers in complex II show no Cu···Cu bonds (Cu···Cu, 2.671(3) Å) and are united to form chains through the axial bridging pivalate groups inherited from palladium monomer I. In contrast, complex III features heterometallic palladium- nickel lanterns in which the Ni atom has an axial α-picoline ligand, while the Pd atom has no axial ligand; instead, a short Pd–Ni bond is formed (2.4976(3) Å). For triplet-state complex III and its zinc analog Pd(μ-OOCCMe3)4Zn(α-Pic) (IV), quantum chemical calculations and topological analysis of the electron density were performed.