Syntheses,Crystal Structures And Properties Of Metal-Organic Frameworks Based On Tetrazole Clusters

Ammonia has a great threat to the health of human beings,so is very important to study its sensing and recognition.The traditional ammonia sensor is generally electrochemical detection of ammonia,highly susceptible to electromagnetic signals,than reduced the sensitivity of the sensor,the researchers are eaged to find more efficient and more sensitive method to detect ammonia.In this paper,we selected Tetraoxazole ligand which can improve the stability of the material,tris(4-tetrazolyl)aniline(H3L),and the color changeable cobalt metal are obtained by solvothermal method to form a new mixed valence porous Metal Organic Frameworks(MOF)(FJU-56),with high thermal stability and excellent chemical stability.The compound FJU-56 can affect the coordination environment of the metal by the interaction of the host and guest hydrogen bonds,so that the material can change color rapidly from red to tawny to identify the ammonia in the water vapor environment.For the first time,we used the single crystal X-ray diffraction technique to determine the position of the adsorbed ammonia molecules in the FJU-56 channel.It was found that unlike the conventional ammonia sensing material,The discoloration mechanism of FJU-56 is the interaction between ammonia and N atoms of MOF skeleton to change the Co ion coordination environment and cause discoloration.FJU-56 is safer,more convenient and quicker than traditional ammonia sensor,and naked eye visible,provided a new idea for the research of ammonia sensor.In addition,we used triazine tetrazolium ligand 1,3,5-tris(4-tetrazolylphenyl)benzene(H3TPB)and metal zinc to form an anionic MOF(FJU-57).It showed good water stability,has good adsorption propertie on the cationic methylene blue dye,but not adsorbed for the anionic methyl orange dye,showing a good cationic selective adsorption performance.Meanwhile,molybdenum is introduced into a single metal MOF skeleton to obtain a bimetallic MOF material(FJU-58),which is due to the presence of Molybdate and able to conduct protons,we conducted an impedance test and found that the sample proton conductivity reached a 10-4 S/cm level at 60 ? at 95%humidity and was a potential proton conducting membrane material.