Effect of Organic Polycarboxylate Ligands on the Structures of a Series of Zinc(II) Coordination Polymers Based on a Conformational Bis-triazole Ligand

To explore the influence of six structurally different
polycarboxylate
ligands H2L1 to H4L6 in
the system Zn­(II)/btmx, six coordination polymers, formulated as [Zn­(btmx)­(L1)]n (1), {[Zn­(btmx)­(L2)]·2H2O}n (2), {[Zn­(btmx)­(L3)]·1.5H2O}n (3), [Zn­(btmx)­(L4)]n (4), {[Zn4(btmx)3(L5)4(H2O)2]·4H2O}n (5), and [Zn­(btmx)­(H2L6)]n (6), have been obtained under similar
conditions (btmx = 1,4-bis­(1,2,4-triazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene,
H2L1 = 1,3-benzenedicarboxylic acid, H2L2 = 1,4-benzenedicarboxylic acid, H2L3 = 1,3-adamantanedicarboxylic acid, H2L4 = 1,3-adamantanediacetic acid, H2L5 = 4,4′-oxidibenzoic acid, and H4L6 =
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 66-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.