Emission properties of cyclodextrin dimers linked with perylene diimide - Effect of cyclodextrin tumbling

Abstract

Perylene diimide (PDI) derivatives with cyclodextrins (PDI-CD 2s) exhibit specific emission properties, which depend on the type of CDs in an aqueous solution. Herein we successfully create an emission film-kneaded PDI-CD 2 derivatives via effective tumbling of the altropyranose unit. PDI-6CD 2 s are crosslinked with PDI between 6-amino-CDs. Although the emission intensities of PDI-6CD 2s in dimethyl sulfoxide are similar regardless of the type of CD, PDI-6γCD 2 has a relatively high emission intensity in aqueous solutions. In contrast, for PDIC 7-3CD 2s, which are linked with N,N′-bis(6- carboxylhexyl)perylene-3,4,9,10-tetracarboxyl diimide (BisC 7-PDI) between 3-amino-CDs, the emission intensity of PDIC 7-3βCD 2 is stronger than those of PDIC 7-3αCD 2, PDIC 7-3γCD 2, and PDI-6CD 2s in aqueous solutions. The selective emission behavior of PDIC 7-3CD 2s is due to the formation of the pseudo1rotaxane dimer through tumbling of the altropyranose unit in an aqueous solution. PDIC 7-3βCD 2 in the solid state does not demonstrate a distinctive emission due to self-quenching, whereas PDIC 7-3βCD 2 kneaded into the polyvinyl alcohol (PVA) film exhibits a bright yellow emission. The order of the emission intensities of PDIC 7-3CD 2s kneaded into PVA films is similar to those in aqueous solutions. © 2012 The Society of Polymer Science, Japan (SPSJ) All rights reserved.