Two azido-bridged homospin Fe(ii)/Co(ii) coordination polymers featuring single-chain magnet behavior

Two azido-bridged homospin Fe(ii)/Co(ii) coordination polymers [Fe-2(Bzp)(2)(N-3)(4)](n) (1) and [Co-4(Bzp)(4)(N-3)(8)(MeOH)(2)](n) (2) (bzp = 2-benzoylpyridine) are prepared, which consist of one-dimensional neutral chains with pure EO-azido (mu(2)-1,1-N-3) bridges. Magnetically, both 1 and 2 exhibit considerable intrachain ferromagnetic interactions which benefit from the EO-azido bridging mode, leading to typical single-chain magnet (SCM) behavior under both the "infinite-size" and "finite-size" regime and pronounced hysteresis loops. As far as the bridging network is concerned, complex 1 represents not only a rare example of homospin Fe(ii)-based SCMs but also the first Fe(ii) chain compound with pure EO-azido bridges.