Intriguing Architectures Generated from 1,4-Bis(3- or 4‑pyridyl)-2,3-diaza-1,3-butadiene with Aromatic Dicarboxylates: Syntheses, Crystal Structures, and Properties

Six
new mixed-ligand coordination polymers, namely, [Zn­(1,3-bdc)­(3-bpdb)]n (1), {[Zn­(1,3-bdc)­(4-bpdb)]­·2H2O}n (2), [Co­(1,4-bdc)­(3-bpdb)­(H2O)2]n (3), [Ni­(1,4-bdc)­(3-bpdb)­(H2O)]n (4), {[Co5(1,4-ndc)4(3-bpdb)­(μ3-OH)2(H2O)2­(DMF)2]­·2H2O­·CH3OH}n (5), and {[Zn2(1,4-ndc)2­(3-bpdb)]­·H2O}n (6), where 3-bpdb =
1,4-bis­(3-pyridyl)-2,3-diaza-1,3-butadiene, 4-bpdb = 1,4-bis­(4-pyridyl)-2,3-diaza-1,3-butadiene,
1,3-H2bdc = 1,3-benzenedicarboxylic acid, 1,4-H2bdc = 1,4-benzenedicarboxylic acid, and 1,4-H2ndc = 1,4-naphthalenedicarboxylic
acid, were synthesized under solvothermal conditions. Single crystal
X-ray diffraction analysis revealed that the structures of complexes 1 and 2 were isomorphic and exhibited two-dimensional
(2D) double-layered sql nets. Complex 3 had
an interesting 2D → three-dimensional (3D) inclined polycatenation
net based on 44-sql subunits. Complex 4 featured an uncommon 3D 2-fold cds network,
while complex 5 possessed a rare uninodal self-penetrating
10-connected pentacobalt-cluster-based ile-(36.434.53.62) framework. Complex 6 displayed a 2-fold interpenetrated 3D six-connected pcu topology. These different intriguing architectures indicated
that the coordination behaviors of metal ions and the coordination
modes, the position isomers of carboxylate, and different steric hindrances
of aromatics played important roles in the construction of CPs; moreover,
bpdb ligands with conformational freedom may affect the formation
of the final architectures. The photoluminescence properties of 1, 2, and 6 in the solid state and
the magnetic properties of 5 were studied. Moreover,
thermal analysis, powder X-ray diffraction, infrared spectroscopy,
and elemental analysis were also performed.