Luminescence of Amphiphilic PtII Complexes Controlled by Confinement

7/26/2018 12:00:00 AM

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Authors:Youssef Atoini, Eko Adi Prasetyanto, Pengkun Chen, Simone Silvestrini, Jack Harrowfield, Luisa De Cola

Publication date: 23 July 2018

Chem. Eur. J

Volume:  24, 12054-12060

Link: https://onlinelibrary.wiley.com/doi/pdf/10.1002/chem.201802743#accessDenialLayout

 

 

Abstract : The  formation   of  hybrid  silica-based  systems  to study the  effect of the  confinement on the  emission proper- ties  of  self-assembled   platinum(II)  complexes   is  reported. The complexes  behave  as  surfactants  since  they  possess  a hydrophobic moiety and, on the  ancillary ligand, a relatively long  hydrophilic  chain terminated with a positively charged group. The compounds, soluble in water, self-assemble, even at   very  low   concentration,  in  supramolecular  structures which  display  an  orange   luminescence.   The  properties  of the  assemblies  have  been  studied  in detail  and  in order  to stabilize these  supramolecular  architectures and  to enhance their  emission  properties hybrid  silica porous  nanoparticles have  been  prepared.   In particular  the  PtII   complexes  have been  employed  as co-surfactant  for the  template formation of  mesoporous silica nanoparticles (MSNs) using  a  sol  gel synthesis.   Interestingly,  upon   encapsulation  in  the   silica pores,  the  platinum  aggregates exhibit  an  emission  profile similar in  energy  to  the  complexes  assembled in solution, but  the  photoluminescence quantum  yields  of  the  hybrid systems are significantly higher (up to 45 %), and the excited state  lifetimes much  longer  than  those  recorded  in solution. Such enhancement of the photophysical properties together with the possibility to process the hybrid silica nanomaterials can pave the way to new type of emitters.