Synthesis and Structural Characterization of a Series of Novel Zn(II)-based MOFs with Pyridine-2,5-dicarboxylate Linkers

A series of novel metal–organic
frameworks comprised of
Zn–O–Zn dinuclear units and multidentate pyridine-2,5-dicarboxylate
linkers were synthesized under mild conditions. The crystal structure
and composition of the novel phases were established from synchrotron
powder diffraction data. Small variations in the parameters of the
synthesis led to formation of the metal–organic systems of
different topologies, either 3D metal–organic frameworks (MOFs)
or a 0D molecular complex. The novel MOFs feature a permanent porosity.
The excess hydrogen uptake measured for the selected MOF sample was
about 0.9 wt % at 77 K and 1 bar. Structural examinations indicated
the phase transformation in several samples caused by the absorption
of the atmospheric water molecules. The thermal stability and guest-molecule
content in the pores of the novel MOFs were also characterized by
TGA-DSC.