The Benzotriazolate Coordination Polymer (1)(infinity)[Eu(Btz)(2)(BtzH)(2)], Containing Divalent Europium

The reaction of europium metal with a melt of the amine 1H-1,2,3-benzotriazole yields single crystalline yellow (1)(infinity)[Eu(Btz)(2)(BtzH)(2)], Btz = 1,23-benzotriazolate anion, C6H4N3-, BtzH = 1H-1,2,3-benzotriazole, C6H5N3, and H-2 gas. No additional solvent was used. The new compound adopts a strand-like structure and exhibits it square anti-prismatic coordination of europium by nitrogen atoms. As europium is divalent, this is the first example of a divalent rare earth benzotrizolate. Both benzotriazolate and benzotriazole ligands function as mu-eta(1):eta(1) linkers between different europium atoms, their third nitrogen atom being involved in intra-strand hydrogen bridges. Although the of each strand call be refined in a smaller subcell, the arrangement of strands to one another necessitates a refinement in a larger supercell.