Synthesis of several novel coordination complexes: ion exchange, magnetic and photocatalytic studies

Eight new coordination polymers (CPs) based on a V-shaped carboxylate ligand H2L (H2L = 5-(1-oxo-1,3-dihydro-isoindol-2-yl)-isophthalic acid), namely {[Zn(L)(H2O)]·H2O}n (1), {[Zn2(L)2(phen)2(H2O)2]·CH3OH·2H2O}n (2), {[Zn(L)(2,2′-bpy)(H2O)]·H2O}n (3), [Zn2(L)2(4,4′-bpy)]n (4), {[Cu(L)(H2O)]·H2O·0.5(CH3OH)·0.5(DMF)}n (5), [Cu3(L)2(phen)3(ClO4)2]n (6), {[Co(L)(dbpy)(H2O)]·3CH3CN}n (7), and {[Co(L)(phen)(H2O)2]·DMA·3H2O}n (8), have been synthesized and characterized by IR, XRD, TG analysis, elemental analysis and single crystal X-ray diffraction measurement. Reactions of H2L and ZnSO4 with different auxiliary ligands in similar solvents occurred at the temperature of 80 °C, yielding similar 1D chains 1–3 and a three-dimensional (3D) framework 4. Besides, reactions of H2L and Cu2+ in the absence or presence of phen formed CPs of 5 and 6 associated with the reduction of dimensionality of the self-assembled products from 3D to 2D. Complex 5 presents a 3D framework with nanosize channels which are comprised of interlocked six-fold one-dimensional helical chains, while compound 6 shows a 2D structure. Additional reactions of H2L, Co2+ and auxiliary ligands give rise to two structurally related 2D CPs 7 and 8. Single-crystal-to-single-crystal studies show that Zn2+ ions in complexes 1–3 could be partially exchanged with Cu2+ ions. And we elaborated the reasons for different exchange degrees by comparing the coordination energies of Zn2+. Furthermore, by comparing the photoluminescence and photocatalytic mutation results induced by the interconversion of metal ions, we confirm that the property mutation induced by metal ions is greatly controllable and obvious. Magnetic studies show that there are strong antiferromagnetic interactions in 5 and 6. Moreover, complexes 5–8 are also applied to catalyze the reaction of MB under high-pressure mercury lamp irradiation.