Unexpected Magnetic Moments in Manganese‐Doped (CdSe)₁₃ Nanoclusters: Role of Ligands

Abstract This study explores the enhancement in magnetic and photoluminescence properties of Mn 2+ ‐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 NaBH 4 (Se‐NaBH 4 ) 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 Mn 2+ ‐doping with tetrahedral coordination, further stabilized by hydrogen‐bonded acetate ligands, as evidenced by 13 C NMR and IR spectroscopy. Mulliken charge analysis indicates that the charge redistribution on Se 2− 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 μ B 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.