Huang, G.L.; Ting, K.Y.; Narayanam, N.; Wu, D.R.; Hsieh, T.E.; Tsai, K.C.; Yang, D.W.; Tang, Q.X.; Su, B.K.; Kang, Y.T.; Huang, S.J.; Chen, C.H.; Chang, Y.P.; Yang, L.S.; Chao, Y.C.; Li, E.Y.T.; Liu, Y.H.: Unexpected Magnetic Moments in Manganese-Doped (CdSe)13 Nanoclusters: Role of Ligands. Angewandte Chemie - International Edition 64 (2025), p. e202420257/1-11
10.1002/anie.202420257
Abstract:
This study explores the enhancement in magnetic and photoluminescence properties of Mn2+-doped (CdSe)13 nanoclusters, significantly influenced by the introduction of paramagnetic centers through doping, facilitated by optimized precursor chemistry and precisely controlled surface ligand interactions. Using a cost-effective and scalable synthesis approach with elemental Se and NaBH4 (Se-NaBH4) in n-octylamine, we tailored bonding configurations (Cd−O, Cd−N, and Cd−Se) on the surface of nanoclusters, as confirmed by EXAFS analysis. These bonding configurations allowed for tunable Mn2+-doping with tetrahedral coordination, further stabilized by hydrogen-bonded acetate ligands, as evidenced by 13C NMR and IR spectroscopy. Mulliken charge analysis indicates that the charge redistribution on Se2− suggests electron transfer between surface ligands and the nanocluster, contributing to spin fluctuations. These tailored configurations markedly increased the nanoclusters′ magnetic susceptibility and photoluminescence efficiency. The resulting nanoclusters demonstrated a clear concentration-dependent response in emission lifetimes and intensities upon exposure to magnetic field effects (MFE) and spin-spin coupling, alongside a large magnetic moment exceeding 40 μB at 180 K. These findings highlight the potential of these nanoclusters for magneto-optical devices and spintronic applications, showcasing their tunable magnetic properties and exciton dynamics.