The solvent-induced topological diversity and different framework stabilities were studied in two Zn(II) metal–organic frameworks (MOFs), {[Zn(L)]·DMA}n (1) and {[Zn(L)]·MeOH·0.5NMP}n (2) (H2L = 5-(4H-1,2,4-triazol-4-yl)isophthalic acid). Despite the fact that both of these MOFs are (3,6)-connected networks based on the same coordination environment of Zn(II) ions and the same coordination mode of the ligands, they adopt distinct nets with apo and rtl topologies, respectively, which originate from the template effects of the solvents and the conformational flexibility of the ligand. The two Zn(II) MOFs show remarkably different framework stability upon guest exchange due to their different topological structures. The luminescent properties of MOF 1 with different solvents have been studied in detail, which shows high sensitivity in the detection of nitrobenzene (NB). In addition, MOF 1 can be reused by simply washing with fresh solvent.