Unexpected retention of the Pd-Ba heterobimetallic structure upon Pd(μ-OOCMe)4Ba(HOOCMe)4 to 18-crown-6 attachment

► Pd(μ-OOCMe)4Ba(HOOCMe)4 reacted with 18-crown-6. ► Crystalline Pd(μ-OOCMe)4Ba(η6-18-crown-6) was synthesized. ► The complex retains the heterometallic Pd@Ba metal skeleton. ► Hydrolysis of Pd@Ba gave two-bridged heterometallic and mononuclear complexes.