Studies On Al³⁺ Ions Sensing Properties Of Schiff Bases And Seurm Protien Interactions Of Their Metal Complexes

Schiff bases are a class of compounds containing an imino group?HC = N? or alkyl imino group?RC = N?, which are synthesized using the active carbonyl compound and a primary amine through condensation reaction. Since the Schiff base compounds containing C = N bond, therefore, the C = N bond hybrid atomic orbitals on the N-containing lone pair of electrons, so that these compounds are endowed with important chemical and biological significance. From the point of view of chemical synthesis, Schiff base compounds can be easily synthesized by a variety of flexible options amines and carbonyl-containing different aldehydes and ketones, which could regulate substituents donor groups and chemical environment, resulting in a series of different properties, changing the structure of Schiff base ligands. In addition, Schiff base metal complexeshave great potential in design and application of this type of molecules. Schiff base compounds and their metal complexes have very broad development prospects, such as in the fields of catalysis, medicine, etc., and optical, electrical, magnetic and functional materials, which caused many scholars studied extensively. Since the Schiff base compounds have a good coordination property, therefore, it plays a vital role in the development of coordination chemistry, especially the development of bio-inorganic chemistry.Obeject: To design, discover, synthesize and screen a series of Schiff bases ligands which are capable of using as new aluminum ion fluorescent probes, and study effects of many factors on structure-activity relationships and fluorescence intensity and fluorescence properties studied in solution. At the same time, using fluorescence spectroscopy and ultraviolet spectroscopy to detect the interactions between thiourea Schiff base metal complexesandserum albumin, which can explore the feasibility of such complexes in tumor cells and provide experimental basis for the application.Methods: Six salicyl aldehydes Schiff base ligands, H2L1-H2L6, were obtained, and H2L2 were screened as the best aluminum ion fluorescence probe molecule. H2L2 is capable of recognizing Al³⁺ in methanol and can produce intense fluorescence. The probe is less susceptible to interference from other metal ions, with strong anti-jamming capability. For the detection of Al³⁺, H2L2 probe showed high sensitivity, good stability, in a certain concentration range with good linearity. Job's plot fitting results showed that H2L2 can react with Al³⁺by 1:1 stoichiometry complexto produce fluorescent effect. Fluorescence properties results showed that under different pH conditions, H2L2 has with good fluorescence in the physiological p H range accordingly, which can be applied to the further development of life-system detection of Al³⁺. On the other hand, the experimental results show that thioureas Schiff base metal complexes may bind serum albumin BSA. Complex 2can quench BSA fluorescence by the dynamic quenching mechanism, while complexes 1,3, and 4were through static quenching mechanism. Thermodynamic investigation results showed that the mode of action Schiff base metal complex 1 and the BSA is hydrophobic forces; and van der Waals forces and hydrogen bonding are the the main mode of action for Schiff base metal complexes 2-4to BSA.Conclusions: By chemical synthesis, structural characterization and fluorescent probe screening,we obtained salicylic aldehyde Schiff base aluminum ion fluorescence probe H2L2. The probe molecule has a selective, high sensitivity, anti-interference ability, at physiological p H under conditions with good fluorescence signal characteristics, with strong development potential. By thiourea Schiff base metal complexes 1-4 with serum albumin BSA binding manner investigation showed that these compounds can bind serum albumin with a strong combination, which can be used for the evaluation of the biological activity of these compounds and provide an experimental basis.