Ligand and pH-Controlled Zn^II Bilayer Coordination Polymers Based on Biphenyl-3,3‘,4,4‘-tetracarboxylate

Abstract

Four novel ZnII coordination polymers, [Zn(btc)0.5(H2O)] n (1), {[Zn(btc)0.5(4,4‘-bpy)0.5(H2O)]·1.5H2O} n (2), {[Zn2(H2btc)2(4,4‘-bpy)4]·H2O} n (3), [Zn(H2btc)(bpe)] n (4) [H4btc = biphenyl-3,3‘,4,4‘-tetracarboxylic acid, 4,4‘-bpy = 4,4‘-bipyridine, and bpe = 1,2-bis(4-pyridyl)ethane], have been synthesized by hydrothermal reactions. Single-crystal X-ray structural analysis reveals that the four polymers exhibit different novel bilayer architectures. Complex 1 possesses a bilayer structure in which two helical layers are further pillared by (btc)4- ligands into a two-dimensional (2D) bilayer network. Complex 2 is an unusual 2D double-layered supramolecular motif generated by hydrogen bonding interactions of two single-layered networks. Complex 3 displays a 2D supramolecular bilayer network formed by the one-dimensional {[Zn2(H2btc)2(4,4‘-bpy)4]·H2O} n polymer. Complex 4 features a 2D double-layered framework in which two puckering single layers are linked by μ2-carboxylato groups of (H2btc)2- anions. The diverse structures illustrate rational adjustment of the second ligand, and the pH value is a good method to further design bilayer metal−organic compounds with novel structures and properties. In addition, the thermal stabilities and photoluminescence properties of 1−4 were also studied.

Synthesis, characterization and crystal structure of a 2D Cd(II) complex with a 4,4'‐diazenediyldiphthalic acid ligand

“…Each Cd(ІІ) ion is sixcoordinated by oxygen atoms from three different L ligands and another three oxygen atoms from three coordinated water molecules, forming a distorted octahedral geometry. The bond lengths of Cd−O range from 2.255(12) to 2.390(14) Å with an average value of 2.283(3) Å , which are similar to those found in other transition-metal complexes of carboxylates [14]. The O−Cd(1)−O angles range from 78.1(5) to 168.2(4)°, which indicates Cd center has a distorted octahedral environment.…”

Synthesis of a two‐dimensional porous framework based on symmetrical organic ligand and linking metal ion

“…This octahedron is normal ( Table 2). The bond lengths of Cu−O range from 1.957(2) to 2.465(4) Å with an average value of 2.259(4) Å, which are similar to those found in other transition-metal complexes of carboxylates [12]. The O−Cu(1)−O angles range from 91.97(13) to 179.2(13)°, which indicates that Cu center has a normal octahedral environment.…”

A New Coordination Polymer Exhibiting Unique 2D Hydrogen‐Bonded (H2O)16 Ring Formation and Water‐Dependent Luminescence Properties

“…Wang et al [19] reported four new coordination polymers through hydrothermal self-assembly with biphenyl-3,3',4,4'-tetracarboxylic acid, Zn II , and bipyridyl ligands as the molecular building blocks. The complexes display luminescence properties resulting from intraA C H T U N G T R E N N U N G liA C H T U N G T R E N N U N G gand fluorescence (p*!p transition).…”