Premium
Directional Energy Transfer in Nanocrystals of [Ru(2,2′‐bipyridine) 3 ][NaCr(oxalate) 3 ]
Author(s) -
Previtera Elia,
Tissot Antoine,
Hauser Andreas
Publication year - 2016
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201501204
Subject(s) - chemistry , crystallite , nanocrystal , luminescence , oxalate , chromophore , fluorescence , emission spectrum , absorption (acoustics) , absorption spectroscopy , 2,2' bipyridine , photochemistry , crystallography , spectral line , nanotechnology , inorganic chemistry , crystal structure , optics , materials science , optoelectronics , physics , astronomy
Size‐controlled nanocrystals (140 and 670 nm) and microcrystals (2.5 μm) of the three‐dimensional oxalate network [Ru(bpy) 3 ][NaCr(ox) 3 ] (ox = oxalate, bpy = 2,2′‐bipyridine) were prepared by the reverse micelle technique. The photophysical properties of the [Cr(ox) 3 ] 3– chromophores in the nanocrystals at low temperatures are significantly different from those of the same chromophore in 4 μm crystallites prepared by fast precipitation. For the latter, the absorption in the region of the R lines of the 4 A 2 → 2 E transition is characterized by a sharp doublet. For the nanocrystals, the inhomogeneous broadening of the two lines is considerably larger and they have tails on the low‐energy side. The 4 μm crystallites at low temperatures show equally sharp emission from the R 1 line, whereas the emission intensity from the nanocrystallites is shifted into the low‐energy tail. Time‐resolved fluorescence line‐narrowing spectra and luminescence decay curves demonstrate that this is due to efficient directional energy migration from the center of the nanocrystals towards the surface.