Synthesis、Characterization And Properties Of The Silver Or Copper Metal Organic Gel

Metal organic gels (MOGs) constitute a subset of solid-like metal ions and bridging organic ligand structures (similar to metal organic framework, MOFs), that form multidimensional network through a trapped solvent as a result of noncovalent interaction. While physical properties of these gels are similar to conventional high molecular weight organic polymer gels, MOGs systems are often fully reversible and can be assembled and disassembled in the presence of additional energy (heat, sonication, shaking). Compared to gels resulting from purely organic self-assembled low molecular weight gelators, metal ions incorporated into the fibrilar networks spanning the bulk solvent can impart MOGs with added functionalities. The solid/liquid nature of the gels allows for species to migrate through the gel system and interact with metals, ligands, and the solvent. Chemosensing, catalysis, fluorescence, and drug-delivery applications are some of the many potential uses for these dynamic systems, taking advantage of the metal ion’s coordination, the organic polydentate ligand’s orientation and functionality, or a combination of these properties. By fine tuning these systems through metal ion and ligand selection and by directing self-assembly with external stimuli the rational synthesis of practical systems can be envisaged.However, the research of MOGs is still in its infancy so far. It has suffered great challenges to chemist in many fields such as fully characterize these novel soft materials, confirm the coordination polymer structure, construct the gelation mechanism and expand the application field of MOGs. The chemist pursuit of goal is to design new MOGs with novel structure and special functionality on purpose.This paper mainly concern to the synthesis of MOGs based on the rigid ligand2,7-bis(1-imidazole)fluorine and pharmaceutical intermediates2-amino-5-thiol-1,3,4-thiadiazole with Ag(I) and Cu(II) salt, respectively. The MOGs obtained have been characterized by1H NMR, SEM, IR, UV-vis. We also studied the responsive of MOGs to various environmental stimuli such as physics, chemistry, the applications in medicine and dye adsorption. The whole work can be summarized as three aspects:1. We have discovered a new series of metallogelators derived from the rigid ligand2,7-bis(1-imidazole) fluorine and three Ag(Ⅰ) salt, respectively, which are characterized by1H NMR, IR, etc. The relationship of their gelation with the organic solvent, the Ag(Ⅰ)/BIF ratio and the Ag(Ⅰ) salt counteranion also discussed in detail. It has found that the gels exhibit multiple responsive to the chemical stimuli such as ultrasound, acid, base, S2-, I-; they display considerable antibacterial properties against Bacillus subtilis, Staphylococcus aureus and Escherichia coli bacteria. Their xerogels showed well adsorption properties against the dye such as acid fuchsin, eosin Y, methyl orange, rhodamine B, and could be recycling and reuse.2. The ultrasonic method applied to synthesize the Cu(Ⅱ)-BIF gel, which showed unique phenomenon, fluorescence "off and on" accompanied with the formation and collapse of gels. The properities could be used to detect the sulfide such as Na2S and H2S by naked eyes. The gel exhibit excellent dye adsorption properties to acid magenta, methylene blue, methyl orange, rhodamine B, crystal violet, pyrrole red.3. Using the pharmaceutical intermediates2-amino-5-thiol-1,3,4-thiadiazole as ligand to react with three silver(Ⅰ) salt respectively, formed a new class of Ag (I)-AMTD MOGs. This polymer system was observed to undergo sol-to-gel transition as the temperature was raised, in contrast with the behavior of most gel-forming polymers, which do so upon cooling. It has found that the sol-gel transition temperature (Tgel) decrease with the proportion of Ag (Ⅰ)/AMTD. The gels display considerable antibacterial properties against Bacillus subtilis, Staphylococcus aureus and Escherichia coli bacteria. Their xerogels showed well adsorption properties against the dye such as acid fuchsin in water, and could be recycling and reuse. It may provides an effective new method to purify sewage.