Issue 39, 2017

Fluorescent carborane–vinylstilbene functionalised octasilsesquioxanes: synthesis, structural, thermal and photophysical properties

Abstract

A new set of four different fluorescent boron-rich hybrids based on an octasilsesquioxane core (T8) are presented herein. The syntheses have been carried out starting from styrene-containing ortho- and meta-carboranes and an adequately substituted octasilsesquixane derivative (p-BrStyrenylOS) via Heck coupling reaction. The carborane clusters are attached to the T8 core through para-substituted stilbene spacers, which act as the main electronic donor of the molecule and as a result are responsible for the photoluminescence properties of the hybrids. These have been assessed in DCM solution, concluding that the presence of the carborane clusters plays a key role in the increase of the fluorescence emission displayed by the hybrids. A comparative study of different substituents (H, Me or Ph) linked to the adjacent carbon atom of the ortho-cluster revealed that the unsubstituted o-carborane derivative (POSS-H) has a much higher quantum yield in solution (ΦF = 59%) than its two counterparts. Besides, a comparison between two hybrids containing phenyl-substituted ortho- (POSS-Ph) and meta-carborane (POSS-mPh), demonstrated a significantly higher emission enhancement by the latter, backing the results we have previously reported for similar systems. In the solid state, the emission is largely quenched in all cases (ΦF = 4 to 7%) as well as bathochromically shifted due to considerable intermolecular interactions. Finally, the thermal resistances of these hybrids were tested by TGA under an inert atmosphere, unveiling weight losses as low as 15.8% and proving that the attachment of the carborane moieties to the T8 core outstandingly improves the thermal stability of the final POSS.

Graphical abstract: Fluorescent carborane–vinylstilbene functionalised octasilsesquioxanes: synthesis, structural, thermal and photophysical properties

Supplementary files

Article information

Article type
Paper
Submitted
24 Jul 2017
Accepted
09 Sep 2017
First published
12 Sep 2017

J. Mater. Chem. C, 2017,5, 10211-10219

Fluorescent carborane–vinylstilbene functionalised octasilsesquioxanes: synthesis, structural, thermal and photophysical properties

J. Cabrera-González, A. Ferrer-Ugalde, S. Bhattacharyya, M. Chaari, F. Teixidor, J. Gierschner and R. Núñez, J. Mater. Chem. C, 2017, 5, 10211 DOI: 10.1039/C7TC03319B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements