Cyanide and imidazolate bridged macrocyclic dinuclear CuII complexes: Synthesis, structure and magnetic properties

Reaction of [Cu2L](ClO4)4 with CH3CN in acetonitrile, and Him in DMF gave cyanide and imidazolate bridged macrocyclic dinuclear copper (II) complexes with the formula [Cu2L(CN)](ClO4)3 (1) and [Cu2L(im)](ClO4)2 · 0.7Br · 0.3Cl, (2), respectively (L = N[(CH2)2NHCH2(C6H4-p)CH2NH(CH2)2]3N). In 2, each Cu(II) atom is coordinated with four macrocyclic nitrogen atoms and one imidazolate N atom, forming a slightly distorted square pyramidal geometry. Magnetic susceptibility measurements of 1 and 2 show that the two Cu(II) atoms of the binuclear unit are antiferromagnetically coupled with g = 2.148, J = −86.09 cm−1 for 1, and g = 2.047, J = −38.20 cm−1 for 2. The correlation between the structures and the J values is discussed.

Graphical abstractCyanide and imidazolate bridged two macrocyclic dinuclear copper (II) complexes were synthesized and their magnetic properties are investigated. The cyanide bridged complex shows stronger antiferromagnetic interactions due to the shorter Cu⋯Cu separation.Figure optionsDownload full-size imageDownload as PowerPoint slide