Synthesis, structure and magnetic properties of a copper molybdate hybrid inorganic/organic solid with a novel 10-connected three-dimensional network topology

Hydrothermal reaction of CuCl2, MoO3, and 4,4′-dipyridylketone (4,4′-dpk) afforded green crystals of the mixed metal oxide phase {[Cu2(MoO4)2(4,4′-dpk)(H2O)]·H2O}n (1). According to single-crystal X-ray diffraction, {Cu2O2} dimers link into 1-D {Cu2O2(μ-H2O)}n chains via bridging aqua ligands. These chains form [Cu2(MoO4)2(H2O)]n slabs via linkage through tetrahedral molybdate anions. In turn, the copper molybdate slabs are pillared through tethering 4,4′-dpk ligands into a 10-connected three-dimensional lattice with an unprecedented 312430526 topology. Variable temperature magnetic data above 140 K were fit to the Curie–Weiss law, with C = 0.17 cm3 K/mol Cu and Θ = 70 K, indicating likely ferromagnetic coupling within the dinuclear kernels of 1; low temperature data points towards the possibility of interdimer antiferromagnetic interactions.

Graphical abstractThe mixed metal oxide phase {[Cu2(MoO4)2(4,4′-dpk)(H2O)]·H2O}n (1, 4,4′-dpk = 4,4′-dipyridylketone) exhibits [Cu2(MoO4)2(H2O)]n slabs that are pillared by 4,4′-dpk ligands into a 10-connected 3-D lattice with an unprecedented 312430526 topology. Ferromagnetic coupling within and antiferromagnetic exchange between {Cu2O2} dimers in 1 is observed.Figure optionsDownload full-size imageDownload as PowerPoint slide