Self-Assembly and Circularly Polarized Luminescence from Achiral Pyrene-Adamantane Conjugates by Selective Inclusion with Cyclodextrins

Abstract

The interaction between guest chromophores or lumiphores with host chiral cavity and their induced chirality is an important topic in supramolecular chemistry. Kodaka and Harata proposed a rule to explain the induced circular dichroism of the guest chromophores by host cyclodextrins. However, it remains unknown how a circularly polarized luminescence (CPL) signal will change when the lumiphores interacted with cyclodextrins in different modes. Here, we designed an achiral pyrene-adamantane conjugated guest molecule, N-(pyren-1-yl)­adamantane-1-carboxamide (ACNP), and investigated its interactions with α/β/γ-cyclodextrins (CDs) and its induced CPL. Depending on the size match of the pyrene, adamantine with different cyclodextrins, distinct performance was observed. While α-CD could not induce a CPL signal of ACNP, β-CD could induce CPL in two modes, through adamantyl or direct pyrenyl induction, which could produce a CPL signal with opposite signs. γ-CD could always induce a negative CPL signal. Therefore, a rule of induced CPL of lumiphores by cyclodextrins can be proposed.

Cyclodextrin-catalyzed self-assembly of a coordinating fluorescent molecule into microflowers

“…This enhanced excimer emission indicates the formation of a pyrene dimer in the barrel-like cavity formed by two γ-CDs. 16–18 The formation of inclusion complexes between 1-PBA/γ-CD is further confirmed by 1 H NMR (Fig. 1c).…”

Circularly polarized luminescence in molecular recognition systems: Recent achievements

“…Liu et al reported selective interactions of a pyrene–adamantane dual‐site guest molecule, N ‐(pyren‐1‐yl)adamantane‐1‐carboxamide (ACNP), with α/β/γ‐cyclodextrins (Figure 2). 69 α‐Cyclodextrin hardly interacted with either site of ACNP effectively and could not induce CPL because the cavity is too small for both the pyrene and adamantane sites. In contrast, β‐cyclodextrin captured both sites, and the resulting β‐cyclodextrin−ACNP 2:1 complex displayed pyrenyl monomer CPL at 390 nm with a g lum value of −4.8 × 10 −3 ([β‐cyclodextrin] = 10 mM, [ACNP] = 0.1 mM).…”

Efficient circularly polarized electroluminescence from achiral luminescent materials

“…The PL peak of S-BNPCN-o-CP becomes weakened gradually by increasing BN3 concentration (Fig. 3e), indicative of FRET process from S-BNPCN-o-CP to BN3 [58][59][60] . In the absence of BN3, only the CP-PL signal at ~400 nm from S-BNPCN-o-CP is observed, without other CP-PL signals.…”