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

Abstract

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.