Two new coordination polymers of Robson-type macrocycle bridged by perchlorate anions: Structure, electrochemistry and magnetism

Two new coordination polymers of Robson-type macrocycles, [Cu2L1(μ-ClO4)2]∞ (1) and [Cu2L2(μ-ClO4)2]∞ (2) (where H2L1and H2L2 are the [2+2] condensation products of 2,6-diformyl-4-flurophenol with 1,3-diaminopropane and 2-hydroxy-1,3-diaminopropane, respectively), have been synthesized and characterized. The intriguing feature is that intermolecular perchlorato bridges occur between adjacent copper(II) centers. The cyclic voltammograms of the complexes show that each complex undergoes two pseudo-reversible processes with the half wave potentials, −0.361 V and −0.729 V for 1, and −0.372 V and −0.744 V for 2, respectively. Magnetic susceptibility was measured for 1 and 2 over a temperature range of 2–300 K. The optimized magnetic data were J = −359.6 cm−1, j′ = −30 cm−1 and R = 6.8 × 10−8 for 1 and J = −411 cm−1, j′ = −26 cm−1 and R = 2.4 × 10−7 for 2, respectively. The data reveal antiferromagnetic couplings between the copper(II) ions of intra- and intermolecular units.

Graphical abstractTwo novel coordination polymers of Robson-type dinuclear macrocyclic complexes, bridged by ClO4-, were synthesized and fully characterized, and the unique property of the complexes is that there is anitferromagnetic interaction between copper(II) ions connected by ClO4-Figure optionsDownload full-size imageDownload as PowerPoint slide