Novel three-dimensional framework based on Co(II)-azide chains and a tetrapyridyl ligand

A new cobalt(II) coordination polymer with azide and a quadritopic ligand, [Co-2(N-3)(4)(TPOM)](n) (TPOM= tetrakis(4-pyridyloxymethylene) methane), was solvothermally synthesized and characterized structurally and magnetically. The compound exhibits a three-dimensional framework in which Co(II) chains with alternating double end-on (EO) and double end-to-end (EE) azide bridges are linked by the tetrapyridyl ligand in a bowl-shaped conformation. With both Co(II) and TPOM as 4-connecting nodes, the structure represents the first real example of the 4-connected net topology with point symbol (3(2).10(4))(3(2).4.10(2).11)(2). Magnetic studies demonstrated that the alternating double EO and double EE azide bridges induce ferro-and antiferromagnetic interactions along the chain. (C) 2011 Elsevier B.V. All rights reserved.