合成了带有两个具有S-立体中心的手性亲水侧链的两亲性氮杂-BODIPY染料(S)-1。该染料在MeOH/H2O(9/1,v/v)混合溶剂中表现出动力学控制的自组装途径和超分子手性多态性。(S)-1单体首先聚集成动力学受控的,非途径物种Agg。A,自发地转化为通路上的亚稳态聚集体(Agg。B),随后进入热力学Agg。C.染料(S)-1的三种聚集体多晶型物显示出不同的光学性质和纳米形态。特别是,对于两种Agg均观察到手性J-聚集特征。B和Agg.C,如Davydov分裂吸收带(Agg.B),极其尖锐和强烈的J带,具有大的红移(Agg.C),聚集时荧光不减弱,以及强烈的双头棉花效应。此外,AFM和TEM研究表明,Agg。A具有纳米颗粒的形态,而Agg分别观察到具有左旋性的原纤维或棒状螺旋纳米结构。B和Agg.C.通过控制Agg的动力学转化过程。B到Agg。C,由Agg组成的薄膜。B和Agg.制备了不同比例的C,显示出可调的CPL,其发射最大值在788-805nm处,g因子在-4.2×10-2和-5.1×10-2之间。
An amphiphilic aza-BODIPY dye (S)-1 bearing two chiral hydrophilic side chains with S-stereogenic centers was synthesized. This dye exhibited kinetic-controlled self-assembly pathways and supramolecular chiral polymorphism properties in MeOH/H2O (9/1, v/v) mixed solvent. The (S)-1 monomers first aggregated into a kinetic controlled, off-pathway species Agg. A, which was spontaneously transformed into an on-pathway metastable aggregate (Agg. B) and subsequently into the thermodynamic Agg. C. The three aggregate polymorphs of dye (S)-1 displayed distinct optical properties and nanomorphologies. In particular, chiral J-aggregation characteristics were observed for both Agg. B and Agg. C, such as Davydov-split absorption bands (Agg. B), extremely sharp and intense J-band with large bathochromic shift (Agg. C), non-diminished fluorescence upon aggregation, as well as strong bisignated Cotton effects. Moreover, the AFM and TEM studies revealed that Agg. A had the morphology of nanoparticle while fibril or rod-like helical nanostructures with left-handedness were observed respectively for Agg. B and Agg. C. By controlling the kinetic transformation process from Agg. B to Agg. C, thin films consisting of Agg. B and Agg. C with different ratios were prepared, which displayed tunable CPL with emission maxima at 788-805 nm and g-factors between -4.2×10-2 and -5.1×10-2.