Atomically Precise Bismuth Oxido Nanoclusters as Hosts for Ln ³⁺ : Effects of Doping on Optical and Magnetic Properties of a Soluble Metal Oxide

High Resolution Image Download MS PowerPoint Slide A series of lanthanoid-doped bismuth oxido nanoclusters (BiO-NCs) of the type [Bi 38 O 45 (NO 3 ) 24 (dmso) y ]:Ln ( C-1:Ln; Ln 3+ = La – Lu, ≠ Pm; y = 26–28) including isostructural host and doped structures is reported. Successful doping with ≈1 ω% of the BiO-NCs was demonstrated by ICP-OES, ESI-MS, and exemplarily by SC XRD analysis for C-1:Gd and C-1:Dy . The dopants are statistically albeit nonuniformly distributed on the lattice position of Bi 3+ and change the optical and magnetic properties of the BiO-NC host material. Altered optical properties (UV–vis and PL) were demonstrated with special focus on C-1:Er, C-1:Yb, and C-2 d:Dy showing dual Bi 3+ and the Ln 3+ specific PL emissions, resulting in characteristic emission combinations over a wide wavelength range from visible to the NIR region and lifetimes up to 0.5 ms. Starting from C-1:Gd and C-1:Dy the methacrylate-substituted BiO-NCs [Bi 38 O 45 (OMc) 24 (EtOH) 14 ]:Gd ( C-2 E:Gd ) and [Bi 38 O 45 (OMc) 24 (EtOH) 14 ]:Dy ( C-2 E:Dy ) were synthesized to finally give solvate-free [Bi 38 O 45 (OMc) 24 ]:Ln ( C-2 d:Gd, C-2 d:Dy ) after drying. The introduction of paramagnetic behavior in the BiO-NC diamagnetic host structure was confirmed by SQUID measurements. We further investigated the suitability of Gd 3+ in C-2 d:Gd as a polarization agent for dynamic nuclear polarization (DNP)-enhanced MAS NMR experiments, which resulted in a proton enhancement factor of approximately 10.