Non-covalent incorporation of some substituted metal phthalocyanines into different gel networks and the effects on the gel properties

Abstract

The use of metallo-phthalocyanines (MPcs) in many technological applications requires the development of specific methods for flexible thin film fabrication. An interesting and simple strategy is the physical encapsulation of MPcs within viscoelastic gel scaffolds. However, non-covalent incorporation of large external molecules into gel networks is a challenge because the balance between dissolution and crystallization in metastable gel phases is likely to be altered changing the properties and/or stability of the material and, therefore, threatening its functionality. In this work, we report preliminary results regarding non-covalent inclusion of MPcs into different gel networks and the effects on their thermal, morphological and mechanical properties. In general, slight variations on the [Formula: see text]were observed for most combinations prepared at well-defined concentrations in the presence of suitable MPcs, except for the organogel made of peracetylated [Formula: see text]-cyclodextrin and the hydrogel made of a bile acid-based gelator. These gels experienced a remarkable enhancement of the [Formula: see text] of ca. 20°C with respect to the pristine gels. Moreover, preservation of monomeric dye species and reduced photodegradation was also observed in some hybrid gels. Relative correlations between thermal stability, morphological features and mechanical properties were also drawn during the study. Maintenance of the catalytic activity of a CuPc immobilized in a supramolecular gel network was also demonstrated by the aerobic oxidation of benzhydrol to benzophenone at room temperature.