Hydrolysis Controlled Synthetic Strategy and Structural Variation of Hydroxyl–Metal Clusters and Metal–Organic Frameworks Based on Tripodal Ether-Linked 1,3,5-Tris(carboxymethoxy)benzene

Abstract

Eight novel coordination polymers were prepared b y a t r i p o d a l e t h e r -l i n k e d t r i c a r b o x y l i c a c i d : [Mn 3 (TCMB) ,5-tris(carboxymethoxy)benzene, 4-abpt = 4amino-3,5-bis(4-pyridyl)-1,2,4-triazole, Hpdta = 4-(1H-tetrazol-5yl)pyridine, and bpee = 1,2-bis(4-pyridyl)ethene). These complexes were characterized by EA, IR, TGA, PXRD, and single crystal XRD. H 3 TCMB is fully deprotonated, and flexible TCMB 3− ligand exhibits nine coordination modes and various conformations. Complex 1 is a 2D coordination polymer constructed from a [Mn(μ 2 -COO) 2 ] n linear chain and [Mn 2 (μ 2 -COO) 2 (μ 3 -COO) 2 ] n double chain combined by hexadentate TCMB 3− spacer. Complex 2 is a beautiful 2D sandwich-like network assembled by layered [Cu 3 (μ 3 -OH) 3 ] n network and typical tripodal hexadentate TCMB 3− ligand. Complex 3 is a 3D coordination polymer constructed from two distinct heptadentate TCMB 3− ligands, in which the ether oxygen atoms take part in coordination. Complex 4 exhibits a 2D double-layered network built by tetranuclear zinc cluster [Zn 4 (μ 2 -COO) 4 (μ 3 -OH) 2 ] pillared by pentadentate TCMB 3− spacer and 4-abpt linker. Complex 5 displays a 3D architecture assembled by tridentate pdta − and heptadentate TCMB 3− ligand with ether−oxygen coordination. Cobalt complexes 6−8 were prepared by similar reactions at slightly different temperatures (85, 100, and 120 °C). Complex 6 is a 3D coordination polymer assembled by tridentate TCMB 3− ligand. Complex 7 is a 3D porous MOF possessing tetranuclear cobalt cluster [Co 4 (μ 2 -COO) 3 (μ 3 -COO) 2 (μ 3 -OH) 2 ] combined by hexadentate and tetradentate TCMB 3− ligands. Complex 8 is a cluster-based 3D porous MOF, which is an isomer of 7 and contains a different tetranuclear cluster [Co 4 (μ 2 -COO) 6 (μ 3 -OH) 2 ] and pentadentate TCMB 3− ligand. PXRD study reveals the hydrolysis reaction mechanism. A hydrolysis controlled synthesis strategy is suggested based on K sp values of metal hydroxides. Their thermal stabilities were investigated. Complexes 1, 2, 7 and 8 present antiferromagnetic and/or ferromagnetic interactions. Their magnetostructural correlations are studied.

Structural Transformation and Spatial Defect Formation of a Co(II) MOF Triggered by Varied Metal-Center Coordination Configuration

“…Furthermore, the TG results confirmed that their main differences in components is only the water molecules. Therefore, the spatial defects should be originated from the distortion of ligand in the transformed framework of 1b at high temperature rather than the collapse of framework due to the removal of ligands . A close look of the pristine structure of 1 suggests that the distortion might be highly related to the flexible L 2– ligand.…”

“…Therefore, the spatial defects should be originated from the distortion of ligand in the transformed framework of 1b at high temperature rather than the collapse of framework due to the removal of ligands. 37 A close look of the pristine structure of 1 suggests that the distortion might be highly related to the flexible L 2− ligand. As mentioned in the structure description part, the porous framework could be considered as the trinuclear clusters-based layers pillared by L 2− ligands.…”

Solvent Influence in Obtaining Diverse Coordination Symmetries of Dy(III) Metal Centers in Coordination Polymers: Synthesis, Characterization, and Luminescent Properties

“…The rational design of LnCPs is quite complicated owing to the higher coordination numbers and flexible coordination spheres exhibited by the lanthanide metal centers. − Flexible linkers offer various conformations to meet the coordination requirements imposed by lanthanide coordination spheres. , The final coordination architectures based on flexible linkers are cooperatively influenced by the conformation of the linker as well as the coordination sphere of the metal center. , Hence, the utilization of flexible linkers has proven to be one of the successful strategies to explore the structural diversity of LnCPs . In addition, the solvent also plays a vital role in the self-assembly process of coordination polymers directly by coordinating with the metal center or indirectly templating the crystal growth process. , When solvents are directly involved in the coordination assembly by coordinating with the metal centers depending upon the bulkiness and steric hindrance of the solvent, it influences the symmetry of the metal coordination sphere thereby affecting the self-assembly process. , …”

Band gap, sorption properties and fluorescence sensing behaviour of a novel 1D→2D cathenane-like cobalt(II)–organic framework

“…As the key components of coordination polymers (CPs), organic ligands play a vital role in the self-assembly of functional CPs with interesting structural topologies (Zhang et al, 2019). In general, the choice of multifunctional organic ligands is a prerequisite for achieving multifunctional MOFs.…”