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oai:figshare.com:article/34034022 2026-09-30T16:28:12Z category_1 category_4 category_915 category_14 category_16 category_873 portal_63 item_type_6 month_year_09_2026

Quantum Mechanical Insights into Magneto–Structural Correlations Governing the Magnetic Relaxation of Non-Dysprosium Butterfly-Shaped {Cr^III₂Ln^III₂} (Ln = Pr, Nd, Tb, Ho, Er) Complexes Amit Gharu (20427405) Keith S. Murray (1497661) Stuart K. Langley (1497673) Kuduva R. Vignesh (3715498) Biophysics Biochemistry Physical Sciences not elsewhere classified Molecular Biology Physiology Chemical Sciences not elsewhere classified structural derivatives containing quantum mechanical insights large qtm rates field smm behavior ab initio </ energy barriers (< slow magnetic relaxation magnetic relaxation mechanism eff </ sub b </ sub 2 </ sub synthesized several non iii </ sup understand smm characteristics best smm characteristics smm characteristics magnetic relaxation u </ j </ >< sub exchange (< smms ). showed zero performing lanthanide mostly true molecule magnets loprop charges kramers ion The Dy^III Kramers ion is generally found in the best-performing lanthanide-based single-molecule magnets (SMMs). Due to large QTM rates, slow magnetic relaxation in non-Kramers ions like Tb^III and Ho^III is rare. Moreover, Ln^III ions coupled with 3d ions often show enhanced SMM behavior due to significant 3d–4f magnetic exchange, but this is mostly true for Dy^III analogues. Despite this, we synthesized several non-Dy^III-based 3d–4f tetranuclear butterfly-shaped complexes that showed zero-field SMM behavior with energy barriers (<i>U</i>_eff) of 36–44 cm^–1 and relatively long relaxation times for the Tb^III and Ho^III examples. In this work, <i>ab initio</i> and DFT calculations on eight butterfly-type {Cr^III₂Ln^III₂} complexes were performed to understand the SMM characteristics of Tb^III and Ho^III analogues, and structural derivatives containing other Ln^III ions (Pr, Nd, Gd, Er) that did not display zero-field SMM behavior. The magnetic relaxation mechanism of individual Ln^III ions, the Cr^III···Ln^III and Ln^III···Ln^III exchange (<i>J</i>) and the correlation between LoProp charges of bridging and capping ligands, and <i>J</i>s were analyzed to understand SMM characteristics. Furthermore, the dependency of <i>U</i>_eff and <i>T</i>_B on the Cr^III···Ln^III <i>J</i>s has been correlated, which suggests that the moderate Cr^III···Ln^III antiferromagnetic exchange with support from ferromagnetic Ln^III···Ln^III exchange leads to the best SMM characteristics. 2026-09-30T00:00:00Z Text Journal contribution 10.1021/acs.inorgchem.6c03746.s001 https://figshare.com/articles/journal_contribution/Quantum_Mechanical_Insights_into_Magneto_Structural_Correlations_Governing_the_Magnetic_Relaxation_of_Non-Dysprosium_Butterfly-Shaped_Cr_sup_III_sup_sub_2_sub_Ln_sup_III_sup_sub_2_sub_Ln_Pr_Nd_Tb_Ho_Er_Complexes/34034022 CC BY-NC 4.0