【摘要】 手性(R,R)-1,2-环己二胺分别与具有偶数亚甲基烷烃链的S-M-1(4,4’-(butane-1,4-diylbis(oxy))-dibenzaldehyde),S-M-2(4,4’-(octane-1,8-diylbis(oxy))dibenzaldehyde)和S-M-3(4,4’-(dodecane-1,12-diylbis(oxy))-dibenzaldehyde)单元,通过亲核取代-消除反应合成相应的新颖柔性高分子P-1,P-2和P-3.Eu(TTA)3·2H2O分别与P-1,P-2和P-3反应制备相应的柔性稀土Eu(Ⅲ)高分子P-4,P-5和P-6.通过对烷烃主链数目的有效调控,能够有效调控稀土Eu(Ⅲ)的发光效率和圆偏振荧光的不对称因子(glum).实验证明,在一定的激发状态下,稀土高分子仅仅显示Eu(Ⅲ)的红色特征荧光,归于高分子将激发态能量基本传递给配位中心的Eu(Ⅲ)离子.通过对稀土Eu(Ⅲ)高分子的荧光寿命和量子效率表征,P-4,P-5和P-6的发光效率依次降低.P-4与P-5圆偏振荧光(CPL)的最大不对称因子(glum)分别为+0.0873和+0.0115,归属为电偶极跃迁(5D0→7F2);P-6最大不对称因子(glum)为+0.0539,归属为磁偶极跃迁(5D0→7F1).通过烷烃主链数目的差异实现对其CPL的有效调控,调控机理归于高分子折叠所引起稀土Eu(Ⅲ)不对称配位环境的变化.更多还原

【Abstract】 The novel flexible polymers with even alkyl chains P-1,P-2 and P-3 are prepared from the monomers S-M-1,S-M-2 and S-M-3 with( R,R)-1,2-aminocyclohexane via a nucleophilic additionelimination reaction,respectively. The Eu( Ⅲ)-grafting chiral polymers P-4,P-5 and P-6 prepared from the corresponding non-conjugated chiral polymers P-1,P-2 and P-3 by direct coordination reaction of Eu( TTA)3·2H2O displayed high quantum yield and tunable circularly polarized luminescence( CPL). The CD profile and glumvalue of dissymmetry of CPL for Eu( Ⅲ) varied with alkyl length of P-1,P-2,and P-3 with high luminescent efficiency observed for P-4,P-5 and P-6. The P-4,P-5 and P-5 all exhibit exclusively red color emission from Eu( Ⅲ)(5D0→7F2) transition due to almost complete excitation energy transfer from the macromolecular chain to the Eu( TTA)3moiety. The fluorescent efficiency of P-4,P-5 and P-6 could be tuned by choicing the alkyl chain and further corroborated by emission quantum yields and emission lifetimes. The glumvalues of the dissymmetry factors of CPL for electronic dipole(5D0→7F2) transition of Eu( Ⅲ) for P-4and P-5 are as large as + 0. 0873 and + 0. 0115,respectively,whereas P-6 exhibits the largest glumvalue of about + 0. 0539 at magnetic dipole(5D0→7F1) transition. Tunable CPL and luminescent efficiency for Eu( Ⅲ) of corresponding Eu( Ⅲ)-grafting polymer reveal the decisive role of alkyl chain in determining asymmetric coordination environment of Eu( Ⅲ).更多还原