Linker dependent dimensionality in Zn(II)-coordination polymers containing a flexible bis-pyridyl-bis-amide ligand

A bis-pyridyl-bis-amide ligand containing a biphenylene scaffold was combined with four different dicarboxylic acids in the presence of Zn(NO3)26H2O under solvothermal conditions, using DMF as solvent. The corresponding coordination frameworks were structurally characterized by single crystal diffraction analysis, the topological and thermal analysis were also conducted. The removing of the included DMF was investigated through solvent assisted activation protocol, the final outcomes being determined by 1HNMR analysis. The dimensionality of the solid networks depends on the type of dicarboxylic acid employed. The use of isophthalic acid and 5-amino-isophthalic acid led to the isolation of 2D-frameworks (PUM20 and PUM32, topological type 3,5L2), while a 1-D polymer was obtained using 2-methoxy-isophthalic acid (PUM30, of topological type SP 1-periodic, ladder-like). Finally, the use of terephthalic acid led to a pillared 2-fold interpenetrated 3D-structure (PUM198, of topological type fet).