Palladium(ii) mononuclear and palladium(ii)/ruthenium(ii) heterodinuclear complexes containing 2-quinolyl-substituted (pyridine-2-carbonyl)hydrazone

Abstract

A reaction of [PdCl₂(cod)] (cod = 1,5-cyclooctadiene) and an E/Z mixture of quinoline-2-carbaldehyde (pyridine-2-carbonyl)hydrazone (HL) gave two kinds of Pd^II mononuclear complexes, [PdCl(Z-L-κ³N,N′,N′′)] (1) and [PdCl₂(E-HL′-κ²N,N′)] (2), where L⁻ is the deprotonated hydrazonate anion and HL′ is the quinolinium–hydrazonate zwitterionic form of HL. Complex 2 is gradually converted to 1 in solution, and complex 1 is a good precursor to prepare a Pd^II/Ru^II heterodinuclear complex bridged by hydrazonate, trans(Cl,Cl)-[RuCl₂(PPh₃)₂(μ-L)PdCl] (3).