Photophysicochemical behaviour of metallophthalocyanines when doped onto silica nanoparticles

• Published in: Dyes and pigments 2017-01, Vol.136, p.262-272
• Main Authors: Oluwole, David O., Nyokong, Tebello
• Format: Article
• Language: English
• Subjects: Fluorescence quantum yields; Phthalocyanines; Silica nanoparticles; Triplet quantum yields
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2016.08.053

Aluminum(III) chloride 2,9(10),16(17),23(24)–tetra–(4–tert–butylphenoxy)phthalocyanine (1), zinc(II) 2,9(10),16(17),23(24)–tetra–(4–tert–butylphenoxy)phthalocyanine (2), zinc(II) 1,8(11),15(18),22(25)–tetra–(4–tert–butylphenoxy) phthalocyanine (3) and zinc(II) 2,9(10),16(17),23(24)–tetra–(4–carboxylphenoxy) phthalocyanine (4) were doped onto silica nanoparticles (SiNPs). There were no significant changes in fluorescence quantum yields and lifetimes of the metallophthalocyanines ( MPcs) when doped onto SiNPs. The triplet quantum yields of the MPcs alone range from 0.22 to 0.85 and in the presence of SiNPs the values range from 0.17 to 0.89. We observed a general decrease of triplet quantum yields of phthalocyanines in the conjugates except for 2 where there was an increase. The values were highly affected by aggregation. Complexes 1 and 3 were highly aggregated when doped onto SiNPs, while 2 and 4 did not show much aggregation. [Display omitted] •Silica nanoparticles (SiNPs) were doped with metallophthalocyanines (MPcs).•There was an increase in triplet quantum yields of MPcs when conjugated to SiNPs.•The highest loading of MPcs was for non-peripherally substituted derivative.