Synthesis,Structural Characterization And Properties Of Organotin And Organozirconium Complexes Derived From Selenoacetic Acid

Since the last century,organotin(IV)complexes are an important class of organometallic chemistry,which have attracted considerable academic and practical focus.Recently,bulks of advances had been made in the synthesis of organotin(IV)complexes possessing attractive biological properties,such as lower general toxicity and fewer side effects,than platinum drugs.Hence,it‘s urgent to synthesize and research organotin(IV)complexes with high biological activity.The effective measures for preventing and treating cancer is to supply selenium.Selenium,one of the trace elements,is closely related to human health,which plays an irreplaceable role in regulating immunity,resisting cell mutation,preventing the occurrence of cancer.The selenium-containing complexes are of extremely significance in nutriology,especially the absorption rate of organoselenium by human is 20 times of inorganoselenium.From the perspective of coordination chemistry,carboxylic acid ligands embody a number of distinct advantages,such as coordination ability through the oxygen electron-donating atoms that allows it to serve as either a multidentate or a bridging building block in structural assemblies.Additionally,there is considerable attention in organometallic chemistry of zirconocene complexes for their particular spatial constructions,as well as their significant application.In light of these reasons,we carried out a series of organotin(IV)and zirconocene complexes bearing selenoacetic acid ligands,and some studies on their structures and properties were conducted systematacially.The main works of this paper are listed below.1.We synthesized a se-containing ligand—4-fluorophenylselenoacetic acid,and chose 4-fluorophenylthioacetic acid and 4-fluorophenylacetic acid,for comparison purposes,combined with di and triorganotin substrates under nitrogen atmosphere using standard Schlenk techniques.Twelve novel organotin(IV)complexes were prepared and characterized by elemental analysis,FT-IR,NMR(1H,13 C and 119Sn)spectroscopy as well as single-crystal X-ray diffraction.The structural analyses reveal that:(1)a 1:1 reaction of Me3 Sn Cl with ligands afforded infinite one-dimensional(1D)polymeric chain composed of alternate [Sn-O]2,while a 1:2 reaction of(n-Bu3Sn)2O with ligands also afforded 1D coordination polymers;(2)a 1:2 reaction of R2 Sn Cl2(R = Me;n-Bu)with ligands afforded ladder-like structure as well as monomer,respectively.The screening test of these organotin(IV)complexes against human breast cancer cell lines(MDA-MB-231)were conducted with MTT-based assays.The obtained results indicate that these complexes exhibit obvious inhibitory efficiency on MDA-MB-231.Definitrly,the organic groups of the organotin precursors contribute largely to their in vitro cytostatic activity,even with the same ligands.The alkyl groups of organotin precursors acts as an important role on their in vitro cytostatic activity.The inhibitory efficiency of these organoseleniumtin complexes against MDA-MB-231 is di-n-butyl > tri-n-butyl > trimethyl > dimethyl.The organosulfurtin complexes and the organotin carboxylates also accord with the above mentioned rule.Additionally,the inhibitory efficiency of organoseleniumtin complexes is the highest compared with corresponding organosulfurtin complexes‘ and the organotin carboxylates‘.The inhibitory efficiency of 1-12 are higher than the cisplatin.2.We synthesized another se-containing ligand—3,4-difluorophenylselenoacetic acid,and chose 3,4-difluorophenylacetic acid for comparison purposes,combined with di and triorganotin substrates under nitrogen atmosphere using standard Schlenk techniques.Six novel organotin(IV)complexes were prepared and characterized by elemental analysis,FT-IR,NMR(1H,13 C and 119Sn)spectroscopy as well as single-crystal X-ray diffraction.The structural analyses reveal that:(1)a 1:1 reaction of Me3 Sn Cl with ligands afforded infinite 1D polymeric chain;(2)a 1:2 reaction of R2 Sn Cl2(R = Me;Ph;n-Bu)with ligands afforded ladder-like structure,drum-like structure as well as monomer,respectively.The screening test of these organotin(IV)complexes against human cervix cancer cell lines(Hela)were conducted with MTT-based assays.The obtained results indicate that these complexes exhibit obvious inhibitory efficiency on Hela.The organic groups of the organotin precursors contribute largely to their in vitro cytostatic activity,even with the same ligands.The alkyl groups of organotin precursors acts as an important role on their in vitro cytostatic activity.The inhibitory efficiency of these organoseleniumtin complexes against Hela is di-n-butyl > trimethyl > dimethyl.The inhibitory efficiency of organoseleniumtin complexes is higher than corresponding organotin carboxylates‘.The inhibitory efficiency of 13-18 is higher than the cisplatins.3.We synthesized se-containing ligand—2-methylphenylselenoacetic acid,combined with di and triorganotin substrates under nitrogen atmosphere using standard Schlenk techniques.Three novel organotin(IV)complexes were prepared and characterized by elemental analysis,FT-IR,NMR(1H,13 C and 119Sn)spectroscopy as well as single-crystal X-ray diffraction.The structural analyses reveal that:(1)a 1:1 reaction of Me3 Sn Cl with 2-methylphenylselenoacetic acid afforded infinite 1D polymeric chain;(2)a 1:2 reaction of R2 Sn Cl2(R = Me;Ph)with 2-methylphenylselenoacetic acid afforded ladder-like structure and drum-like structure,respectively.4.We synthesized a class of se-containing ligand—2-thienylselenoacetic acid,phenylselenoacetic acid,4-fluorophenylselenoacetic acid,3-fluorophenylselenoacetic acid,3,4-difluorophenylselenoacetic acid and 2,4,6-trimethyl-phenylselenoacetic acid.Six novel zirconocene complexes were synthesized and characterized by elemental analysis,FT-IR,NMR(1H and 13C)spectroscopy,X-Ray powder diffraction as well as single-crystal X-ray diffraction.The structural analyses reveal that: a 1:1 reaction of Cp2 Zr Cl2 with corresponding se-containing carboxylic ligands obtained trinuclear zirconocene complexes.In summary,different reaction conditions(e.g.: the proportion of reagent,the species of solvent)contributed to the synthesis of organotin(IV)and zirconocene complexes.Typical intermolecular weak interactions can enrich the structure of organotin(IV)and zirconocene complexes,including hydrogen bond,C-H···? interactions and ?···? interactions.It is worth to note that selenium-containing organotin carboxylates display better in vitro cytostatic activity,indicating that these complexes possess potential pharmaceutical value.