Synthesis and characterization of the free ligand 5,6:13,14‐dibenzo‐9,10‐benzo(15‐crown‐5)‐2,3‐bis(hydroxyimino)‐7,12‐dioxo‐1,4,8,11‐tetraazacyclotetradecane and its mono and tri nuclear complexes

The novel (E,E)‐dioxime 5,6:13,14‐dibenzo‐9,10‐benzo(15‐crown‐5)‐2,3‐bis(hydroxyimino)‐7,12‐dioxo‐1,4,8,11‐tetraazacyclotetradecane (H 2 L) has been synthesized by the reaction of 4′,5′‐diaminobenzo(15‐crown‐5) with N,N′‐bis(2‐carbomethoxyphenyl)diaminoglyoxime (1). Only mononuclear Co III and Ru II complexes with a metal/ligand ratio of 1:2 have been isolated. The cobalt(III) complex bridged with BF 2 + is achieved with H‐bonded cobalt(III) complex and borontrifluoride ethyl ether complex. The reaction of BF 2 bridged cobalt(III) complex with bis(benzonitril)palladium(II) chloride gives a trinuclear complex. The structures of dioxime and its complexes are proposed according to elemental analyses, 1 H and 13 C‐NMR, IR and mass spectral data.