1. Photoswitchable 11 nm CsCoFe Prussian Blue Analogue Nanocrystals with High Relaxation Temperature
- Author
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Laure Catala, Serhane Zerdane, Eric Rivière, Nada Dia, Diana Dragoe, Christian Herrero, Talal Mallah, Marco Cammarata, Sandra Mazerat, Eric Collet, Linh Trinh, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique, CNRS, ANR-13-BS04-0002-03, Institut Universitaire de France, IUF, ANR-13-BS04-0002,FEMTOMAT,Etude femtoseconde rayons X et optique de la dynamique ultrarapide de photocommutation de matériaux moléculaires magnétiques(2013), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Ternary alloys ,Cobalt alloys ,Cetyltrimethylammonium ,Cobalt metallography ,Structural techniques ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,010402 general chemistry ,01 natural sciences ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,Colloid ,Charge transfer ,law ,Electron spin resonance spectroscopy ,Metastability ,Vacancy defect ,Iron alloys ,medicine ,Photoinduced charge transfer ,Physical and Theoretical Chemistry ,Electron paramagnetic resonance ,Coordination networks ,Vacancy concentration ,[PHYS]Physics [physics] ,Prussian blue ,Polyvinylpyrrolidone ,010405 organic chemistry ,Chemistry ,Organic polymers ,Relaxation temperature ,Nanocrystals ,0104 chemical sciences ,Iron metallography ,Prussian blue analogues ,Crystallography ,Nanocrystal ,Sols ,Diamagnetism ,Polyvinyl pyrrolidone ,medicine.drug - Abstract
International audience; Photoswitchable 11 nm nanocrystals with the coordination network Cs{Co[Fe(CN)6]} were obtained using a template-free method. The nanocrystals were recovered from the colloidal solutions as solid materials surrounded by cetyltrimethylammonium (CTA) cations or embedded in the organic polymer polyvinylpyrrolidone (PVP). Complementary magnetic, spectroscopic, and structural techniques, including EPR spectroscopy, reveal a majority (∼70%) of the low-spin and photoactive diamagnetic CoIIIFeII pairs located in the core of the nanocrystals and a mixture of CoIIFeII and CoIIFeIII species present mainly within the shell of the objects. While bulk compounds with similar vacancy concentration do not exhibit noticeable photoinduced charge transfer, the observed photoactivity of the nanocrystals is ascribed to their nanometric size. The relaxation temperature of the photoinduced state shifts upward by ∼55 K when PVP is replaced by CTA. This is ascribed to the larger rigidity of the dense CsCoFe_CTA material, whose metastable state is lower than that for CsCoFe_PVP, leading to a larger relaxation energy barrier and, therefore, to a higher relaxation temperature.
- Published
- 2020
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