Extended Networks of Co2+ and Mn2+ Bridged by NCS–/N3– Anions and Flexible Long Spacers: Syntheses, Structures, and Magnetic Properties

TLDR: In this article, four new metal-organic polymers with short anion bridges and flexible long spacers were synthesized and characterized by single-crystal X-ray diffraction studies and their magnetic properties were investigated.

Abstract: Four new metal-organic polymers with SCN–/N3– anion bridges and flexible long spacers L {L = bim [1,2-bis(imidazol-1-yl)ethane] and bte [1,2-bis(1,2,4-triazol-1-yl)ethane]}, [Co(SCN)2(bim)] (1-Co), [Co(SCN)2(bte)] (2-Co), [Mn(N3)2(bte)] (3-Mn), and [Mn(N3)2(bim)] (4-Mn), were synthesized and characterized by single-crystal X-ray diffraction studies and their magnetic properties were investigated. Complex 1-Co is a triple-bridging chain complex with double end-to-end SCN– anions and single gauche-bim spacers as bridges. Complexes 2-Co and 3-Mn both contain 1D chains bridged by double end-to-end SCN– or N3– anions and these chains are further extended to 2D (4,4) layers by the anti-bte spacers. Complex 4-Mn has a topological 3D diamond structure constructed through 1D double end-on azide-bridged MnII chains and extended through the anti-bim spacers. Magnetic measurements reveal that 1-Co and 3-Mn remain paramagnetic; the dominant magnetic coupling between CoII is weak ferromagnetic and that between MnII is strong antiferromagnetic. As for 2-Co and 4-Mn, they show metamagnetic behavior below TN = 2.9 and 3.0 K, respectively. Our results show that a combination of the short anion bridges (SCN–/N3–) and flexible bidentate long spacers can be used to construct coordination polymers with novel topologies and interesting magnetic properties. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)