Terphenyl-based Acid Construct Four Metal - Organic Framework Compounds And Their Properties

Currently, the design and synthesis of porous metal-organic frameworks (MOFs) have attracted ever-increasing interest due to their structural aesthetics as well as their potential applications in a variety of fields, including gas storage, separation, ion exchange, catalysis, sensors, magnetic properties and so on. In the past decades, a number of functional coordination polymers have been fabricated by employing rigid aromatic multicarboxylates as linkers, such as1,4-benzenedicarboxylate acid, benzene-1,3,5-tricarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid and4,4’-biphenyl-dicarboxylic acid. In most cases, multicarboxylic ligands are engaged in the construction of high-dimensional architectures which can keep their robust frameworks after the removal of guest molecules and provide convenience in the subsequent research. In this work, the quadrangular shaped [1,1’:4’,1"-terphenyl]-2’,4,4",5’-tetracarboxylic acid (p-H4tptc) and [1,1’:4’,1"-terphenyl]-2’,3,3",5’-tetracarboxylic acid (m-H4ptc) have been chosen as the building block to construct functional MOFs, on the consideration as the following four aspects:(1) synthetic conditions, configurations and bridging modes of two ligands;(2) conditions and characteristics in constructing non-interpenetrated open frameworks incorporating1D metal-carboxylate chains;(3) effects of the sizes and types of the solvent molecules on the syntheses and structures of the compounds;(4) magnetic studies of different1D metal-carboxylate chains.We have selected P-H4tptc and m-H4tptc as building blocks to construct coordination polymers, respectively, co-reacting with appropriate metal ions. Under the hydrothermal reacyion,13coordination polymers have been obtained by self-assembly principle of crystal engineering:[Co2(p-tptc)(H2O)4]n·5n(H2O)(1),[Mn2(p-tptc)]n (2),[Mn2(p-tptc)(DMA)3]n (3),[Cd(p-tptc)0.5(H2O)2]n·n(DMA)(4),[Mn2(p-tptc)(H20)(NMP)]n·n(NMP)(5),[M2(p-tptc)(H2O)(DMA)]n·n(DMA)(6)(M=Mn为6, Co为9),[Mn2(p-tptc)(DMF)2]n (7),[Ni2(p-tptc)(H2O)2]n·n(DMA)-3n(H2O)(8),[Zn(m-tptc)o.5(DMF)]n (10),[Cd(m-tptc)0.5(H2O)]n·n(H2O)(11),[Pb(m-tptc)0.5(H2O)]n (12) and [Mn3(μ3-OH)2(m-tptc)(H2O)4]n (13). All these compounds were characterized by powder X-ray diffraction (PXRD), infrared spectra (IR), elemental analyses (EA) and thermogravimetric analyses (TGA). The structure and topology network of compounds have been described in detail, compared with each other and summarized. The potential luminescence, adsorption and magnetic properties of some compounds have also been tested and investigated.