Luminescent coordination polymers constructed from mixed-ligand strategy for highly selective luminescence sensing of nitrobenzene, Fe3+ and Cr2O72- ions and photodegradation of rhodamine B

By using mixed-ligand strategy, ten new LCPs (Luminescent Coordination Polymers), namely, [Cd(IPA-NH2)(Htpim)]n (1), [Mn(IPA-NH2)(Htpim)]n (2), [Zn(IPA-OH)(Htpim)]n (3), [Cd(IPA-OH)(Htpim)]n (4), {[Zn(Htpim)2(H2O)2](IPA-OH)}n (5), {[Cd(Htpim)2(H2O)2](IPA-OH)}n (6), [Cd(IPA-NO2)(Htpim)]n (7), [Zn2(PMA)(Htpim)2]n (8), [Cd2(PMA)(Htpim)2]n (9) and [Cu(H2PMA)(Htpim)2(H2O)]n (10) (Htpim = 2,4,5-tri(4-pyridyl)-imidazole, H2IPA-NH2 = 5-aminoisophthalic acid, H2IPA-OH = 5-hydroxyisophthalic acid, H2IPA-NO2 = 5-nitroisophthalic acid, H4PMA = 1,2,4,5-benzenetetracarboxylic acid) have been constructed. Compounds 1-4 and 7-9 take similar 2D 44 networks, while 5, 6 and 10 show 1D chain structures. The results reveal that the coordination configuration of M(II), carboxylic acids, and coordinated water molecules act a pivotal part in the formation of final structures. Moreover, the selective luminescence sensing and photocatalytic performances of 1–10 were also studied. Interestingly, they can sensitively detect trace amounts of nitrobenzene (NB), Cr2O72− or Fe3+ through luminescence quenching, respectively. In addition, 3–10 show high photocatalytic activities toward degradation of Rhodamine B (RhB).