A linear Cu II–Gd III–Cu II–Gd III complex derived from the assembly reaction of [NaCu IIH 3L dpen(meso)] and [Gd III(thd) 3(H 2O) 2] (H 3L = meso-1,2-diphenyl-1-(2-oxybenzamido)-2-(2-oxy-3-ethoxybenzylideneamino)ethane and Hthd = 2,2,6,6-tetra-methyl-3,5-heptanedione)

Abstract

A linear tetranuclear Cu II–Gd III–Cu II–Gd III complex [Cu IIL dpen( meso )Gd III(thd) 2(H 2O)] 2 was synthesized from the reaction of [NaCu IIL dpen( meso )(DMF)] with [Gd III(thd) 3(H 2O) 2], and the structures and magnetic properties were investigated, where H 3L dpen( meso ) = meso-1,2-diphenyl-1-(2-hydroxybenzamido)-2-(2-hydroxy-3-ethoxybenzylideneamino)ethane and Hthd = 2,2,6,6-tetramethyl-3,5-heptanedione. The Cu II complex component [NaCu IIL dpen( meso )(DMF)] has a one-dimensional (1D) chain structure, in which the Na + ion is coordinated by two phenoxo and an ethoxy oxygen atoms of a Cu II complex and an amido oxygen atom of the adjacent Cu II unit to produce the 1D structure, in which the diphenylethylenediamine moieties have the array of {(1 R,2 S)-Na-(1 S,2 R)} 1∞. The assembly reaction of the Cu II and Gd III components gave a linear complex with the array of Cu(1)–Gd(1)–Cu(2)–Gd(2), in which two diphenylethylenediamine moieties have the same chirality of (1 R,2 S)-(1 R,2 S) or (1 S,2 R)-(1 S,2 R). Two linear Cu(1)–Gd(1)–Cu(2)–Gd(2) units are linked by hydrogen bonds through two water molecules to give a cyclic structure with a center of symmetry. The temperature dependence of the magnetic susceptibilities and field-dependent magnetization revealed the ferromagnetic interaction between the Cu II and Gd III ions within the linear chain.