Synthesis,structure Characterization And Properties Of Organotin Complexes Derived From Hydroxycinnamic Acid And Aminophosphonic Acid

As a major section of organometallic chemistry,organotin chemistry has attracted the attention of many chemical researchers and medical researchers because of its excellent applications in the fields of synthesis,catalysis,insecticide,antibacterial,and anti-cancer.Nowadays,a large number of organotin complexes base on carboxylic acid,phosphonic acids,sulfonic acid and selenite have been successfully synthesized and found that there are many organotin complexes with good biological activity.Therefore,the research on the synthesis,structure and biological activity of organotin has a significant effect on the development of current chemistry and medicine.Organotin complexes show a variety of structure and properties.The diversity not only depends on the properties of organotin precursor,but also depends on the properties of ligands.In the synthesis process of organotin complexes,the design and selection of ligands is a critical step.Carboxylic acid and phosphonic acid compounds are very important ligands.From structure,a variety of coordination modes can be presented,which is beneficial for the diversity of organotin complexes.Based on the above statement,we chose 4-hydroxy-3-methoxycinnamic acid（ferulic acid）and 4-hydroxy-3,5-dimethoxycinnamic acid（sinapic acid）in hydroxycinnamic acid and aminophosphonic acid compounds as ligands to synthesize new organotin complexes,and further characterize their structure and properties.This article mainly introduces the synthetic methods and structural characterization of new organotin complexes,and then explores the in vitro anticancer activity and their binding effects with BSA.The specific work is as follows:1.Ferulic acid was selected as the ligand to react with trihydrocarbyltin chloride and dihydrocarbyltin oxide to synthesize five organotin ferulate complexes 1-5.（1）In the reaction between the ligand and triphenyltin chloride,the monomer structure complex is obtained by the reaction in the molar ratio of 1:1,and the 1D chain structure complex is obtained in the ratio of 1:2.The reaction with trimethyltin chloride to synthesize a 1D chain structure complex,but the complex synthesized is a monomer structure when4,4’-bipyridine is present.In addition,the complex obtained by reacting with di-n-butyltin oxide is also a monomer.（2）The tin atoms of the complexes synthesized by ferulic acid and trihydrocarbyltin chloride present a penta-coordinated trigonal bipyramid geometry.And the tin atom of the complex synthesized by ferulic acid and dihydrocarbyl tin oxide presents a hexa-coordinated skewed octahedral geometry.（3）The intermolecular O-H···O force makes the organotin ferulate complexes further form a 2D network or 3D space supramolecular structure.2.Sinapic acid was selected as the ligand to react with trihydrocarbyltin chloride to synthesize three organotin sinapate complexes 6-8.（1）In the reaction between ligand and trihydrocarbyltin chloride,all organotin complexes are 1D chain structures.（2）In these complexes,the tin atoms coordinated with the phenolic hydroxyl group are tetra-coordinated mode,and the tin atoms coordinated with the carboxyl group are penta-coordinated mode.（3）These 1D chain structures of organotin sinapates complexes can form a layered 3D supramolecular space structure through the intermolecular interactions O-H···O and C-H···O.3.Benzylamino dimethyl diphosphonic acid was selected as the ligand to react with trihydrocarbyltin chloride to synthesize three organotin phosphonate complexes 9-11.（1）The ligand reacts with trimethyltin chloride in a ratio of 1:3 to obtain a 3D structure containing 16-membered ring and 32-membered ring.And the ligand reacts with tri-n-butyltin chloride in a ratio of 1:4 to obtain a 1D ribbon structure containing another16-membered ring.（2）All tin atoms in organotin aminophosphonates complexes derived from trimethyltin chloride are in penta-coordination mode.And there are tetra-coordinated and penta-coordinated tin atoms in organotin aminophosphonates complexes derived from tri-n-butyltin chloride.4.The half inhibition rates(IC₅₀)of some complexes on human cervical cancer cell lines（He La）and human hepatocellular carcinoma cell lines（Hep G-2）was measured by MTT method.And the interaction of some complexes with bovine serum albumin（BSA）was studied by fluorescence test.The study of in vitro anti-cancer biological activity experiments shows that organotin hydroxycinnamates and aminophosphonates complexes synthesized from phenyltin and n-butyltin have outstanding anti-cancer activity.These complexes have significant inhibitory effects on He La and Hep G-2,and are better than cisplatin.Through the fluorescence spectrum test of the interaction between the complexes and BSA,it can be found that these complexes could quench the intrinsic fluorescence of BSA in a static way.At the same time,it can be seen from the synchronous fluorescence spectroscopic studies that the complexes also has a quenching effect on the fluorescence intensity of tyrosine and tryptophan.