The Studies On Synthesis And Oxygen Sensing Properties Of Mesoporous Composite Materials Based On (Cu,Re)Complexes

Taking transition metal complexes as an optical sensing probe will be very promising in the field of oxygen sensing since it possesses such strengths as being simple, fast, non-invasive detecting. However, in order that the analyte reaches full diffusion without self-quenching between optical sensors, it is often required to link the sensor analysis to supporting medium through chemical or physical approach. Inorganic mesoporous material, such as silicon molecular sieve bear many merits, such as light stability in visible region, big specific surface-area and easy loading sensing molecules, making them good supporting media in the system of optical sensing. In the project, Alkylation function is used to transfer the optical oxygen sensor probe into the hole on the wall the silicon-based mesoporous materials, the combination of inorganic-organic materials can be implemented in the nanometer scale by physical or chemical reactions. Then the composite materials mesoporous-based are character by using UV-vis absorption spectrum and fluorescence spectrum or the change of material. In the composite materials, organic group with optical sensing property can not only become the active center, but also modulate the surface properties of mesoporous material including hydrophilicity, hydrophobicity and the pore size, thus achieving synergy. By single crystal analysis and density functional theory, the paper makes a study of the crystal structure, electronic property and photophysical property of the synthesized complexes and it also carries out an analysis of the oxygen sensing properties such as sensitivity and good photo stability of the composite material loaded with complex.The main researches are as follows:(1)A new Phen-Np-Et and its corresponding [Cu(Phen-Np-Et)(POP)]BF4 are synthesized. On this basis the paper makes a study of the crystal structure, electronic property and photophysical property of Phen-Np-Et and its corresponding complex. The study shows that under the condition of pure nitrogen, the excited lifetime of the yellow luminescence of this complex can last for 287 microseconds. With theoretical calculation it indicates that the luminescence originates from excited charge transfer state from the combination of triplet metal and the complex. Then, in mingling [Cu(Phen-Np-Et)(POP)]BF4 with the matrix of polystyrene and MCM-41, two composite materials based on copper complexes and mesoporous are formed. After analyzing its oxygen sensing features, it shows that the maximum sensitivity of[Cu(Phen-Np-Et)(POP)]BF4/PS and [Cu(Phen-Np-Et)(POP)]BF4/MCM-41 s respectively 9.6 and 3.6. The high sensitivity to oxygen is decided by the relatively big surface area of Nanofibers mesoporous materials and mesoporous material MCM-41.(2) The synthesis characterizes four nitrogen-containing ligands with different length of conjugate and substituents and their corresponding [Cu(N-N)(PPh3)2]BF4 (N-N represents nitrogen-containing ligands:TYP, PPO, PTOå'ŒPBI). Their geometric and electronic structures are studied by single crystal analysis and density functional theory. By comparing the photophysical property of the series of complex, the relationship between nitrogen-containing ligands and luminescence is explained in detail. Study shows that excited state is more subject to the attack(influence) of oxygen, and thus they are expected to be oxygen sensing probe. Afterwards, the series of [Cu(N-N)(PPh3)2]BF4 are mingled with Silicon-based mesoporous materials SBA-15 and four corresponding [Cu(N-N)(PPh3)2]BF4/SBA-15 are formed after assembling. Then their oxygen sensing property is analyzed systematically and finally Composite mesoporous materials with high sensitivity and good photo stability are acquired.(3) In the research, a novel diamine ligand of 4,7-dinonadecyl-1,10-phenanthroline (DN-Phen) with two long alkyl chain arms serving as a shield and its corresponding dinuclear Re(I) complex of Re2(CO)6(bpy)(DN-Phen)2. With two long alkyl chains as a protective coating, the ligand acquires an optical sensor free from external interference. The geometric and electronic structure of this ligand is studied and it shows that the long alkyl chains introduced can act as the protective coating of excited luminescence centers. The excellent photophysical properties of Re2(CO)6(bpy)(DN-Phen), including the luminescence free from external interference and long excited lifetime, makes its application into oxygen sensing possible. By mingling Re2(CO)6(bpy)(DN-Phen) with two Silicon molecular sieves MCM-41 and SBA-15, the oxygen sensing property of the two composite materials are acquired. Ultimately, the highest sensitivity of 20.1 is obtained and the response and reduction time are respectively 8 seconds and 42 seconds. In addition, the composite bears excellent photo stability without obvious photo bleaching.