Ambient Phosphorescence From Donor-Acceptor Bola-Amphiphilic Heterodimers in Aqueous Media

Bola-amphiphilic di-cationic heterodimers with donor-acceptor moieties were explored for generating ambient phosphorescence in aqueous media through different strategies. The use of macrocyclic host cucurbit[8]uril led to host-guest complexes with significantly enhanced phosphorescence. Additionally, the presence of cationic moieties in these derivatives allowed them to form electrostatically driven co-assemblies in the presence of (bio)anionic templates such as biopolymer heparin or synthetic polymer polyacrylic acid, with the latter template giving rise to noticeable improvement in the phosphorescence features. In the presence of heparin, the co-assemblies showed induced chirality, which was dependent on the sample preparation protocol. Moreover, the exchange of the original bromide counterions with a bulky borate counterion such as tetrakis(pentafluorophenyl)borate led to a significant increase in the phosphorescence intensity of the self-assemblies in aqueous media.