Synthesis And Properties Of A Novel Polystyrene Macroligand And Its Metal Complexes

In this paper, a novel polystyrene macroligand was synthesized via combination of atomtransfer radical polymerization (ATRP) and click reaction. Coordination reactions of thepolystyrene macroligand with metal ions were carried out to synthesize its zinc complexesand copper complexes. The fluorescence properties of the complexes were investigated.ATRP of styrene was carried out using1-bromoethylbenzene as an initiator, CuBr as acatalyst, N,N,N’,N’’,N’’-pentamethyl diethylenetriamine (PMDETA) or2,2’-bipyridine (bpy) asa catalyst ligand and toluene as a reaction solvent. Influences of reaction time, ligand type,monomer to initiator molar ratio, monomer concentration, reaction temperature on ATRP ofstyrene were discussed. The results indicated that the reaction rate of ATRP increased withthe decrease of monomer to initiator molar ratio, the increase of monomer concentration andreaction temperature, when PMDETA was as a catalyst ligand. The polymerization reactionexhibited the characteristics of a "living"/controlled polymerization, and molecular weightcontrolled bromine-terminated polystyrene (PS-Br) with narrow polydispersity was obtained.Azido reaction of PS-Br was carried out by using sodium azide (NaN3) to giveazidoe-terminated polystyrene (PS-N3).5-Bromoquinolin-8-ol was synthesized from8-hydroxy quinoline. Reactions between5-bromoquinolin-8-ol and acetic anhydride, benzyl chloride, di-tert-butyl dicarbonate, werecarried out respectively, so that hydroxy group of5-bromoquinolin-8-ol was protected tosynthesize5-bromoquinolin-8-ol derivatives (5-bromo-8-quinoly acetate,5-bromo-8-benzyloxyquinoline and5-bromo-8-tert-butoxycarbonyloxyquinoline). Sonagashira couplingreaction and elimination reaction of hydroxy protection of5-bromoquinolin-8-ol derivativeswere investigated and8-tert-butoxycarbonyloxy-5-ethynylquinoline was synthesized. Then anovel polystyrene macroligand with8-hydroxyquinoline as coordination group wassynthesized via click reaction between PS-N3and8-tert-butoxycarbonyloxy-5-ethynylquinoline followed by elimination of butoxycarbonyl group.Polystyrene zinc complexes and copper complexes were synthesized via coordinationreaction between the novel polystyrene macroligand and zinc ion or copper ion. Thecomplexes could be used as luminescent materials, because they showed fluorescence emission at509nm and540nm, respectively.