Two unique isomorphic Zn2 + and Co2 +-based metal-organic frameworks comprising octahedral cage

Abstract

Two Zn2+ and Co2+-based metal-organic frameworks, [Zn4(L)4(4,4′-bpy)(H2O)2] 2H2O 2CH3CN (1) and [Co4(L)4(4,4′-bpy)(H2O)2].2H2O (2), have been synthesized hydrothermally from mixed ligands of H2L (4,4′-dicarboxy-4″-nitrotriphenyl-amine) and 4,4′-bpy (4,4′-bipyridine). Single-crystal X-ray crystallography reveals that compounds 1 and 2 are isomorphic both featuring a 2-D square-grid layer assembled from one-dimensional cage-connected-cage chain and 4,4′-bpy pillar. Both compounds exhibits one-dimensional rhombus channel with the dimension of about 14.12×7.62Å2 along the c axis. Compound 1 shows strong photoluminescence which has the capability of selective sensing of Fe3+ ion in DMAc.