In silico approach towards nanostructuring of dysprosium bis(amide)–alkene based single-ion magnet onto 1D, 2D, and 3D Network

Abstract

Single-ion magnets (SIMs) are promising candidates for molecular spintronics and quantum technologies; however, their integration into functional nanostructures remains a significant challenge. In this work, we present a comprehensive theoretical investigation of a high-performance dysprosium bis(amide)–alkene complex, [Dy{N(SiiPr₃)[SiiPr₂C(CH₃)=CHCH₃]}{N(SiiPr₃)(SiiPr₂Et)}]⁺ (1), embedded in three distinct environments: a one-dimensional carbon nanotube (CNT(20,0)), a two-dimensional Au(111) surface, and the three-dimensional porous framework MOF-177. By combining periodic density functional theory (pDFT) and CASSCF-SO calculations, we elucidate the influence of dimensionality on SIM behavior across these assemblies. pDFT calculations predict binding energies of −236.5, −71.8, and −68.7 kcal mol⁻¹ for 1@CNT, 1@Au(111), and 1@MOF-177, respectively, while structural analysis reveals that the molecular geometry remains largely preserved upon incorporation. CASSCF-SO results performed on DFT optimized geometry show stabilization of the |±15/2⟩ ground state with near-ideal Ising-type anisotropy (gzz ≈ 19.98–19.99) in all cases. The computed ab initio barrier heights (Ucal) are 1564.3, 1525.5, and 1904.9 cm⁻¹ for 1@CNT,1@MOF-177, and 1@Au(111), respectively, which is close to the U_cal value of 1820.4 cm⁻¹ observed for 1. Notably, deposition of 1 on Au(111) leads to the opening of the N–Dy–N bond angle, increasing the magnetic anisotropy barrier, and suppressing the quantum tunneling of magnetization by approximately two orders of magnitude compared to 1. Importantly, both DFT and multireference calculations confirm that molecular properties and SIM behavior are retained across all three environments, highlighting a viable strategy for organizing magnetic molecules at the nanoscale. Overall, this study demonstrates that surface-induced ligand-field engineering can outperform confinement-based approaches, identifying Au(111) as a particularly promising platform for stabilizing such high-performance SIMs.