Five three/two-fold interpenetrating architectures from self-assembly of fluorene-2,7-dicarboxylic acid derivatives and d10 metals

Abstract

Five new three/two-fold interpenetrated coordination polymers, namely, [Cd(mfda)(L¹)] (1), [Cd(efda)(L¹)] (2), [Zn₂(mfda)₂(L²)]·DMF·H₂O (3), [Zn₂(efda)₂(L²)]·(DMF)_0.25, (4) and [Cd₂(mfda)₂(L²)₂]·DMF·H₂O (5) (H₂mfda = 9,9-dimethylfluorene-2,7-dicarboxylic acid, H₂efda = 9,9-diethylfluorene-2,7-dicarboxylic acid, L¹ = Methylene bis(3,5-dimethylpyrazole) and L² = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene), have been synthesized under solvent-thermal conditions with mixed ligands. Compounds 1 and 2 are isostructural and possess two-dimensional (6, 3) layered structures containing two kinds of rings. Three equivalent (6, 3) net interpenetrate in a parallel fashion to form an unprecedented mat-like 2D sheet. Compounds 3 and 4 are almost identical in structure and display threefold interpenetrating α–Po net structures. Compound 5 displays a twofold interpenetrated 3D 6-connected net with α–Po topology. The luminescent properties of these compounds have been studied in the solid state at room temperature.