Photophysical studies of an encapsulated neutral guest intercalated into the 2-dimensional space of α-Zr(iv) phosphate

Abstract

Our long-range objective of developing surface anchored supramolecular assemblies as artificial light harvesting systems led us to explore the intercalation of guest molecules confined within octaamine hydrochloride (OAm·HCl) in the 2-dimensional galleries of layered inorganic material α-Zr(IV)phosphate (α-ZrP). Photophysical properties of 4,4′-dimethylbenzil, camphorthione, 4,4′-dimethylstilbene, pyrene and coumarin-1 were used to probe the intercalation behavior of OAm capsules within the galleries of α-ZrP. ¹H NMR and emission spectral investigations suggested the inclusion of guests within OAm and also confirmed the stability of host–guest complexes under acidic conditions in water. Stirring guest encapsulated OAm capsule with exfoliated α-ZrP nanosheets resulted in intercalation of the host–guest assembly as a whole in the case of 4,4′-dimethylbenzil, camphorthione, and 4,4′-dimethylstilbene as guests. According to powder X-ray diffraction and emission data these capsules are stable in the galleries of α-ZrP. The fact that the capsules are stable and can be included in α-ZrP nanosheets opens up further opportunities to explore inclusion of two different capsules, one with a donor and the other with an acceptor, and study the energy and electron transfer phenomenon between neutral molecules in α-ZrP galleries.