Yüklü Yüzeylere Sahip Metal Organik Kafeslerin Zwitteriyonik Ligandlarla Sentezi, Karakterizasyonu, Fotokromik Özelliklerinin Ve Karbondioksit Adsorplama Kapasitelerinin Araştırılması

Coordination polymers which have high surface area and permanent porosity are known as metal-organic frameworks (MOFs). MOFs have been had some appication areas such as small molecule adsorption, magnetic materials, sensor, catalysis, gas separation and storage. Especially, in recent years, the investigation of MOFs as color changing material to external stimuli response to light, heat, solvent and water molecules has been increased expectations for new applications. Nowadays, color change has received scientific interest due to various potential applications in various high-tech fields such as window, rewrittable copy papers, sensors, secret writing, brand protection and anti-counterfeiting. Zwitterionic ligands which have potisively charged cationic group and negatively charged anionic group in the structures have been designed in the syntheses of smart MOFs. Thus, charged organic surfaces (COS) formed by ZW ligand in the structure of MOF will help to more polarization of guest molecules like CO2. Moreover, charged groups in the structure of MOFs will produce free radicals with electron transfer by absorbing light and respond by changing color against external stimuli. 

In the project proposal, the design of smart MOF having charged surfaces with zwitterionic ligands which are both high CO2 adsorption capacity and also color change under light is aimed. To achive this goal, triazine and pyridine derivative zwitterionic ligands which have both positive and also negative charges in the structure will be designed. MOFs will be synthesized with ZW ligands in the presence of Cu(II), Zn(II) and Cd(II) ions and characterized. The walls of MOFs will be charged with the effect of ZW ligand and thus, the adsorption amount will be increased due to more interaction with CO2. Furthermore, it is predicted that CO2 molecules will interact with electron pairs in the nitrogens of the triazine rings or CN group. It is planned that -CH2- groups in the structure of ZW ligands will gain flexibility to ligands and thus, ligands will connect to metal ions easily. The electrons in the structure of ZW-ligand in the MOF acting inside MOF will generate radicals with the effect of light and color conversion will be occured. Moreover, to reach the high surface area and pore size, original ligands with three arms and 120 ° angle are designed. ZW-MOFs will be synthesized with hydro(solvo)thermal method using Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions. The structures of MOFs will be characterized by elemental analysis, FT-IR spectroscopy, single and powder X-ray diffractions. Thermal and photoluminescence properties will be investigated with thermal anlaysis and photoluminescence spectroscopy. MOFs will be activated under vacuum and their BET surface areas and CO2 adsorption capacities will be investigated. Color changing properties will be studied under 365 nm light and color changing will be followed with solid state UV-Vis. spectroscopy. Radical formation in the color transformation mechanism will be determined with ESR method.  

When the project is successfully completed, the obtaining results will be published high impact SCI journal and presented various scientific conferences. This project will contribute to come out scientists about this subject. Furthermore, MOFs which have high adsorption capacity and response to light by changing color will be patentable. 

It is planned that project will be finished in 24 months and two researcher and three scholar will work.