Effect of organic polycarboxylate ligands on the structures of a series of zinc(II) coordination polymers based on a conformational bis-triazole ligand

摘要

To explore the influence of six structurally different polycarboxylate ligands H _2L ~1 to H _4L ~6 in the system Zn(II)/btmx, six coordination polymers, formulated as [Zn(btmx)(L ~1)] _n (1), {[Zn(btmx)(L ~2)]?2H _2O} _n (2), {[Zn(btmx)(L ~3)]?1.5H _2O} _n (3), [Zn(btmx)(L ~4)] _n (4), {[Zn _4(btmx) _3(L ~5) _4(H _2O) _2]?4H _2O} _n (5), and [Zn(btmx)(H _2L ~6)] _n (6), have been obtained under similar conditions (btmx = 1,4-bis(1,2,4-triazol-1-ylmethyl)-2,3,5,6- tetramethylbenzene, H _2L ~1 = 1,3-benzenedicarboxylic acid, H _2L ~2 = 1,4-benzenedicarboxylic acid, H _2L ~3 = 1,3-adamantanedicarboxylic acid, H _2L ~4= 1,3-adamantanediacetic acid, H _2L ~5 = 4,4′- oxidibenzoic acid, and H _4L ~6 = 3,3′,4,4′- benzophenone tetracarboxylic acid). The structure determination reveals that complexes 1 and 4 are two-dimensional (2D) layered networks and exhibit typical (4,4) topological nets. Complex 2 shows an undulating 2D (4,4)-network with 2-fold interpenetration. Complex 3 possesses a three-dimensional (3D) 3-fold interpenetrating 4-connected framework of 6 ~6-dia topology. Both 5 and 6 have different 3D interpenetrated motifs generated by 2D → 3D interpenetration. Complex 5 belongs to a 3D framework built from the interpenetration of 2D bilayers in an inclined mode, while 6 involves a parallel interpenetration between the adjacent 2D (4,4) layers. This work markedly indicates that the effect of polycarboxylate ligands is significant in the construction of these networks.