The Study Of The Syntheses Of Rare Earth Metal Coordination Polymers In Ionic Liquids And Their Properties

As a kind of green solvents,ionic liquids have attracted a lot of attention in recently years,for its unique properties such as low melting point,low volatility,large liquid range and so on.Compared to the traditional molecular solvents,the ionic liquid utilized as reactive solvents may result in rare-earth metal coordination polymers(Ln-CPs)with novel structures and benigh fluorescent properties.This thesis is focused on the syntheses and characterizations of a series of lanthanide coordination polymers employing the commercial ionic liquids or the as-synthesized new ionic liquids as reactive solvents,with emphasis on the studies of luminescent properites of the resulting compounds.1.In this part,we report on two isomorphous water-stable Ln-Cps synthesized via microwave-assisted ionothermal methods,namely[Hmim]Ln(DHBDC)2 {Ln?Eu(1),Tb(2);Hmim=1-hexyl-3-methylimidazolium;H2DHBDC =2,5-dihydroxytelephthalic acid}.The large and hydrophobic[Hmim]+ cations in the channels of the compounds with the three-dimensional(3D)anionic framework structures may protect the metal-centre from hydrolysis.Under the radiation of 365 um UV light,1 exhibited a very weak emission at room temperature(RT),but a bright red emission at 77 K,indicating that 1 has potential applications as fluorescent thermometer.Furthermore,the compound showed detection capability to Ba2+ ion through a process of luminescence enhancement,which can be distinguished clearly with the naked eye.When the ionic liquid[CNC3mim]Cl(CNC3mim =l-cyanopropy-3-methylimidazolium)was used,a new Ln-CP was obtained,namely[CNC3mim]Eu(DHBDC)2(3),which possess the similar 3D anionic framework as that of 1 and 2.Due to the presence of hydrophilic-CN group,another new Ln-CP,namely[CNC3mim]Eu(H2O)2(DHBDC)2(4),could be obtained from a hydration process of 3 which involves in a surprising crystal-to-crystal transformation.The structure of 4 is comparable to that of 3 while the local corrdination enviroments of metal ions and the space groups are different.2.A series of antimony-based ionic liquids were obtained by introducing SbCl3 into a series of imidazole chlorine salt ionic liquids,for Cl-is easily coordinated with Sb3+ to form a[SbCln]3-n anion.The as-prepared ionic liquids include[Bmim]2SbCl5(5)(Bmim = l-butyl-3-methylimidazolium),[Bzmim]6[SbCl6][SbCl5]Cl(6)(Bzmim?1-benzyl-3-methylimidazolium),[Bzmim]2[SbCl5](7),[HOOCMmim]3[SbCl5]Cl(8)(HOOCMmim = l-carboxymethyl-3-methylimidazolium),and[HOOCMmim]3SbCl6+3(OOCMmim]·H2O(9).As a new kind of functional ionic liquids,they exhibit excellent fluorescent properties.For instance,the fluorescent quantum yield of 5 could reach as high as 86.3%under UV irradiation.Furthermore,we tried to synthesize Ln-CPs by using these novel ionic liquids.As a preliminary result,the compound[Ce(OOCMmim)2(H2O)5][SbCl6]·H2O(10)was obtained and characterized.