Self-assembly of a terbium(III) 1D coordination polymer on mica.

Quentin Evrard,Andrea Caneschi,Kevin Bernot,Yan Suffren,Guillaume Calvez,Giuseppe Cucinotta,Matteo Mannini,Carole Daiguebonne,Felix Houard,Olivier Guillou

doi:10.3762/bjnano.10.234

Abstract

The terbium(III) ion is a particularly suitable candidate for the creation of surface-based magnetic and luminescent devices. In the present work, we report the epitaxial growth of needle-like objects composed of [Tb(hfac)3·2H2O]n (where hfac = hexafluoroacetylacetonate) polymeric units on muscovite mica, which is observed by atomic force microscopy. The needle-like shape mimics the structure observed in the crystalline bulk material. The growth of this molecular organization is assisted by water adsorption on the freshly air-cleaved muscovite mica. This deposition technique allows for the observation of a significant amount of nanochains grown along three preferential directions 60° apart from another. The magnetic properties and the luminescence of the nanochains can be detected without the need of surface-dedicated instrumentation. The intermediate value of the observed luminescence lifetime of the deposits (132 µs) compared to that of the bulk (375 µs) and the CHCl3 solution (13 µs) further reinforces the idea of water-induced growth.

Highlights

The study of materials for the realization of novel magnetic [1,2,3,4], luminescent [5,6,7] or magneto-luminescent [8,9] devices is a very active research area
The mica substrate was chosen because of its low roughness [23] making it suitable for atomic force microscopy (AFM) imaging [24] as well as for its hydrophilic nature promoting the interaction with the deposited molecules
We report on highly luminescent and magnetic terbium one-dimensional coordination polymers on a mica substrate with the possible formula [Tb(hfac)3·2H2O]n@mica

Summary

Introduction

The study of materials for the realization of novel magnetic [1,2,3,4], luminescent [5,6,7] or magneto-luminescent [8,9] devices is a very active research area These devices rely on functional materials made of magnetically or optically active molecules deposited on surfaces or embedded in host matrices. Similar to what has been observed for other lanthanide ions, the luminescence emission spectrum is characterized by a line shape that is barely affected by the ionic environment because of the inner nature of the 4f orbitals [15] This emission can be considerably enhanced when the ions are properly coordinated by organic ligands that act as “antennas” for UV irradiation increasing the overall brightness of the compound [14]

Results

Discussion

Conclusion