| Abstract
| - Syntheses, lanthanide quantitative analyses, mass spectrometry and luminescence spectroscopy, and decay dynamicsof crystals containing pentanuclear hetero-lanthanide(III) nanoclusters [(Ln‘5-xLnx)(NO3)6(μ5-OH)(μ4-L)2] (0 ≤x ≤ 5), Ln‘ = Eu or Tb; Ln = La−Nd, Sm−Ho (hereafter Ln‘5-xLnx) were undertaken in search of informationon factors governing self-assembly processes by which the clusters are formed and electronic interactions withinand between them. The data obtained are consistent with the self-assembly of Ln‘5-xLnx nanoclusters being aconcerted process featuring a profound expression of complementarity among mutually bridging [Ln(μ4-L]- and[Ln(NO3)2]+ components. The energy transport regime in crystals of Eu5-xLnx is in the dynamic regime when x= 0 or Ln = La and, at 293 K, Ln = Dy, despite the presence of two crystallographically different Eu3+ coordinationenvironments which give rise to a doublet in the excitation and emission spectra of Eu3+(5D0). The luminescencedecay behavior of Eu3+(5D0) in Eu5-xLnx (Ln = Dy (for 77 K), Sm) is intermediate between the static and dynamiclimits and reveals extensive electronic coupling among lanthanide ions, including many-body processes at relativelyhigh Dy3+ or Sm3+ concentrations.
- Assembly of small hetero-pentanuclear nanoclusters with lanthanide(III) ions in different coordination environments is governed by cooperative processes in which metal ions are placed in locations from where they contribute most to the stability of the cluster. Resulting nano-aggregates feature remarkably efficient excitation energy transport facilitated by cooperative action of several coupled lanthanide(III) ions.
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