SOLID C60-FULLERENE DERIVATIVES:

PHOTOPHYSICAL PROPERTIES AND

EVALUATION AS SINGLET OXYGEN SENSITIZERS.

Bourdelande, J.L.,⁽¹⁾ Font, J.⁽¹⁾ and González-Moreno, R.⁽¹⁾

Nonell, S.⁽²⁾

⁽¹⁾Unitat de Química Orgànica, Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain. E-mail: iqor2@cc.uab.es

⁽²⁾Institut Químic de Sarrià, Universitat Ramón Llull, Via Augusta 390, 08017 Barcelona, Spain. E-mail: nonel@iqs.url.es

 

INTRODUCTION

Many efforts have been devoted to clarify the properties of fullerenes since they were discovered some years ago [ 1-11] . The photophysical behaviour of C₆₀ (Figure 1) in solution is well known [ 8-11] , and the eventual application of solid C₆₀ derivatives in the field of new materials science has stimulated also the publication of many data about the properties of such derivatives in the solid state. In this context we have, already, carried out some studies on the photophysical properties of pure solid C₆₀, [ 12] , C₆₀ covalently bound to insoluble cross-linked polystyrene, Ps-C₆₀ [ 13] , and solid 2:1 inclusion complex g -cyclodextrin-C₆₀, [ 14] . For these studies we have used the diffuse reflectance laser flash photolysis (DRLFP) technique developed by F. Wilkinson [ 15] that allows the characterization of the photophysical properties of many solid and opaque substances [ 16-18] . In all the above mentioned samples we have detected the transient triplet of solid C₆₀. We show, here, some data for C₆₀ and Ps-C₆₀ as well as some information for S-C₆₀ (C₆₀ covalently bound to insoluble cross-linked Sephadex), and Calix-C₆₀ (1:1 inclusion complex calix[ 8] arene-C₆₀). For all samples we have evaluated the ability of molecular oxygen to deactivate the excited solid triplets. For the polymer Ps-C₆₀ we have used the front-face, time-resolved 1270-nm phosphorescence detection technique to observe the O2(1Dg) emission coming from its surface [ 19] .