The influence of nitro groups on the topology and gas sorption property of extended Zn(II)-paddlewheel MOFs

The synthesis of three nitro-functionalized Zn(II)-paddlewheel based metal-organic frameworks (MOFs) and a Zn(II)-based 2D coordination polymer are reported. While 2-nitro-[1,1'-biphenyl]-4,4'-dicarboxylic acid (bpdc-NO2) is readily incorporated into structure of extended DMOF (DMOF = 1,4-diazabicyclo[2.2.2]-octane MOF) and BMOF (BMOF = 4,4'-bipyridine MOF), 2,2'-dinitro-[1,1'-biphenyl]-4,4'-dicarboxylic acid (bpdc-[NO2](2)) is only incorporated into the structure of BMOF. Furthermore, it is proposed that intermolecular interactions between the nitro groups influence the topology of these frameworks producing unexpected interpenetration in BMOF-1-bpdc-[NO2](2). Gas sorption studies of these functionalized frameworks also reveal effects of the nitro groups on topology as manifest in their gas sorption behaviour.