A comparative photophysicochemical study of phthalocyanines encapsulated in core–shell silica nanoparticles

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2015-02, Vol.137, p.294-299
• Main Authors: Fashina, Adedayo, Amuhaya, Edith, Nyokong, Tebello
• Format: Article
• Language: English
• Subjects: Carboxyphenoxy phthalocyanine; Core–shell; Silica matrix; Triplet quantum yields
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2014.08.062

When phthalocyanine complexes were encapsulated within silica matrix to form a core shell, there was an improvement in the triplet quantum yields and singlet oxygen quantum yields when compared to the surface grafted derivatives. •Three phthalocyanine complexes were encapsulated within silica matrix.•The core shell and the hybrid nanoparticles particles were spherical and mono dispersed.•The core shell showed improved triplet quantum yields and singlet oxygen quantum yields. This work presents the synthesis and characterization of a new zinc phthalocyanine complex tetrasubstituted with 3-carboxyphenoxy in the peripheral position. The photophysical properties of the new complex are compared with those of phthalocyanines tetra substituted with 3-carboxyphenoxy or 4-carboxyphenoxy at non-peripheral positions. Three phthalocyanine complexes were encapsulated within silica matrix to form a core shell and the hybrid nanoparticles particles obtained were spherical and mono dispersed. When encapsulated within the silica shell nanoparticles, phthalocyanines showed improved triplet quantum yields and singlet oxygen quantum yields than surface grafted derivatives. The improvements observed could be attributed to the protection provided for the phthalocyanine complexes by the silica matrix.