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

Abstract

Abstract Four new metal‐organic polymers with SCN – /N 3 – 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(N 3 ) 2 (bte)] ( 3‐Mn ), and [Mn(N 3 ) 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 N 3 – 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 Mn II chains and extended through the anti ‐bim spacers. Magnetic measurements reveal that 1‐Co and 3‐Mn remain paramagnetic; the dominant magnetic coupling between Co II is weak ferromagnetic and that between Mn II is strong antiferromagnetic. As for 2‐Co and 4‐Mn , they show metamagnetic behavior below T N = 2.9 and 3.0 K, respectively. Our results show that a combination of the short anion bridges (SCN – /N 3 – ) 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)