Syntheses And Properties Of Metal-Organic Frameworks Constructed From Cyclotriveratrylene Derivatives

Metal-Organic Frameworks?MOFs?have attracted the attention and active participation of researchers due to their well-defined structure and high porosity.The introduction of a bowl-shaped cyclotriveratrylene derivatives as a ligand into MOFs enables the synthesis of novel materials with novel structures and excellent properties.In this paper,six MOFs were synthesized by using the new cyclotriveratrylene derivative?HECTV=5,6,12,13,19,20-hexaimidazolium-ethoxy-cyclo triveratrylene?as a neutral ligand and introducing organic carboxylic acid ligands under solvothermal conditions.Their catalytic properties as heterogeneous catalysts and luminescence properties were investigated based on their structural characteristics.1.By using a novel imidazole-functional cyclotriveratrylene derivatives ligand?HECTV?,two isostructural frameworks,[Cd₃?HECTV??bdc?₃]·DMF·6H₂O?1?and[Zn₃?HECTV??OH-bdc?₃]·3DMF·4H₂O?2?were constructed.Interestingly,1demonstrates a single-crystal to single-crystal transformation with the guests exchanged by a cycloalkane solvent.Strikingly,1 and 2 feature highly heterogeneous catalytic activities for Knoevenagel condensation.In particular,catalysts 1 and 2could be reused with the good catalytic performance.2.The catalytic activity of the epoxy compound with CO₂ cycloaddition with epoxides was investigated by the synthesized 1 and 2.2 can be used as a heterogeneous catalyst to efficiently catalyze the epoxides for CO₂ cycloaddition with epoxides.By comparing the catalytic activities of 1 and 2,it was found that the catalytic activity of 2 is higher than 1.This is caused by the influence of the polar phenolic hydroxyl group of the OH-bdc anion in 2.It is noteworthy that 1 and 2 are particularly highly stable and can be easily separated and reused with no significant changes in catalytic activity.3.We investigated the luminescent properties of MOFs 1 and 2.1 can be used to detect Fe³⁺.2 can be used as a potential sensing material for detecting nitrobenzene compounds due to the luminescence quenching effect,it also has a good luminescence response to acetone and acetone vapors,and can be used as a luminescence sensor for detecting acetone.4.Four novel MOFs,[Zn₆?HECTV??bdc?₅?HCOO?₂]·4DMF·2H₂O?3?,[Cd₃?HECTV??bdc?₃]·6.5H₂O?4?,[Cd₃?HECTV??OH-bdc?₂?H₂O?₂]·DMF·2H₂O?5?and[Co₃?HECTV??L1?₃]·9DMF·9H₂O?6??H₂L1=4,4'-Stilbenedicarboxylic acid?were synthesized by HECTV.3-6 have different 2D or 3D structures.The addition of organic carboxylic acid ligands makes the synthesized MOFs present different structures.At the same time,we also studied the luminescent properties of 3-5.