Synthesis And Application Of Seminaphthorhodafluor Derivatives Bridged Periodic Mesoporous Organosilicas

Periodic mesoporous silicas（PMO）as one of the organic-inorganic hybrid materials have a wide range of applications in catalysis,adsorption,optics and biomedicine and other fields due to its own structural advantages.Some functional organic groups as bridged groups were homogeneously distributed in the pore walls of mesoporous materials at the molecular level,thus,PMOs not only have the characteristics of mesoporous silica,such as adjustable and uniform pore size,high specific surface area and large pore volume,but also exhibit various properties and functions that mesoporous silica don’t possess due to the diversity of bridging organic groups.When fluorescent dyes are introduced into mesoporous materials as organicbridged groups,the stability of fluorophores is increased and PMOs have fluorescent properties.In this paper,a novel photochromic system and periodic mesoporous silicas fluorescence sensor are designed and synthesized with seminaphthorhodafluor.The main research content is as follows:Firstly,a derivative of seminaphthorhodafluor schiff base is synthesized by using seminaphthorhodafluor（SNARF）compounds and p-hydroxybenzaldehyde,which can form a novel photochromic system of SNARF-SB-Cu²⁺ by complexing with copper ions.The complex undergoes a significant color and spectral changes in solution in the presence of UV light,while in the absence of UV light（dark）,the complex returns to its initial state.In this system,the complex of SNARF-SB and copper ions are necessary to produce photochromic phenomena.The factors affecting the photochromic system（temperature,solvent,acidity and alkalinity,etc.）were studied,and the temperature can regulate the conversion rate of the system,and the acidity and alkalinity of the solution will destroy the photochromic behavior of the system.The system is simple to synthesize,has good reversibility and excellent fatigue resistance.Two INHIBIT logic gates were constructed using this photochromic system,with UV irradiation and Al³⁺or UV irradiation and Cu²⁺as input signals,absorbance and fluorescence intensity as output signals,respectively.In addition,SNARF is highly selective for copper ions and can be used as a fluorescence sensor for Cu²⁺.The fluorescent probe has a high sensitivity with a detection limit of 0.956×10^-7 M.Secondly,periodic mesoporous organosilicas（SSPMOs）were prepared by hydrolysis and condensation of organosilicon precursor（SS-Si）and inorganic silicon source（TEOS）under alkaline condition in the presence of CTAB template.The material has two-dimensional hexagonal ordered mesoporous structure when the content of SS-Si was low,and the degree of order is reduced with high content of SSSi.The fluorescence enhancement of SSPMOs towards Cu²⁺was induced by ringopening of the spirolactam in SNARF-SB in framework of SSPMOs.SSPMOs are served as a fluorescence sensor for detecting copper ions with high selectivity.The sensor also has the advantages of high sensitivity with the detection limit of 5.1×10^-7 M,long fluorescence life,reusability,and good stability.