Two water-bridged cobalt(II) chains with isomeric naphthoate spacers: from metamagnetic to single-chain magnetic behaviour

摘要

The crystal structures and magnetic behaviours of two water-bridged one-dimensional (1D) cobalt(II) chains with different isomeric naphthoate (na(-)) terminals, [Co(H2O)(3)(2-na)(2)](n) (1) and {[Co(H2O)(3)(1-na)(2)]center dot 2H(2)O}(n) (2), were reported to investigate the effect of interchain distance on their magnetic properties. Complex 1 with trans-2-na(-) blocks and dense interchain separation exhibits a metamagnetic transition from antiferromagnetic ordering to a saturated paramagnetic phase. By contrast, complex 2 possessing cis-arranged 1-na(-) spacers and good interchain isolation shows unusual single-chain magnetic behavior under a zero dc field. Thus, completely different interchain packing by isomeric naphthoate ligands governs the ratio of intra-to inter-chain magnetic interactions and further results in different magnetic phenomena, which provide significant magnetostructural information on 1D magnetic systems.