Optical limiters with improved performance based on nanoconjugates of thiol substituted phthalocyanine with CdSe quantum dots and Ag nanoparticlesElectronic supplementary information (ESI) available: 1H-NMR, UV-Vis, FT-IR, MALDI TOF MS, EDX data for synthesized compounds and conjugates. See DOI: 10.1039/c7dt03867d

• Main Authors: Oluwole, David O, Yagodin, Alexey V, Britton, Jonathan, Martynov, Alexander G, Gorbunova, Yulia G, Tsivadze, Aslan Yu, Nyokong, Tebello
• Format: Journal Article
• Language: English
• Published: 28.11.2017
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt03867d

Two alternative synthetic approaches affording a low-symmetry A 3 B-type phthalocyanine 1 bearing two [2′-(2′′-mercaptoethoxy)ethoxy] anchoring substituents were developed. Due to the presence of thiol groups, this phthalocyanine could be conjugated with TOPO-capped (TOPO - trioctylphosphine)-capped CdSe quantum dots ( CdSe-QDs ) or oleylamine capped silver nanoparticles ( Ag-NPs ). The nonlinear optical behaviour of starting phthalocyanine, quantum dots, nanoparticles and their conjugates was studied by using an open aperture Z -scan technique, revealing that the grafting of 1 onto the nanomaterials resulted in a significant enhancement of the optical limiting of 1 -Ag and 1 -CdSe in comparison with the individual components. The conjugate 1 -CdSe , being the first example of Pc-based thiol conjugated with quantum dots, revealed superior limiting characteristics with a limiting threshold below 0.18 J cm −2 . Grafting of thiolated phthalocyanine onto quantum dots and nanoparticles provided conjugates with prominent optical limiting.