Slow Magnetic Relaxation in Octahedral Cobalt(II) Field-Induced Single-Ion Magnet with Positive Axial and Large Rhombic Anisotropy

Pseudooctahedral mononuclear cobat­(II) complex [Co­(abpt)2(tcm)2] (1), where abpt = 4-amino-3,5-bis­(2-pyridyl)-1,2,4-triazole and tcm = tricyanomethanide anion, shows field-induced slow relaxation of magnetization with U = 86.2 K and large axial and rhombic single-ion zero-field-splitting parameters, D = +48(2) cm–1 and E/D = 0.27(2) (D = +53.7 cm–1 and E/D = 0.29 from ab initio CASSCF/NEVPT2 calculations), thus presenting a new example of a field-induced single-ion magnet with transversal magnetic anisotropy.

假八面体单核钴(II)配合物[Co(abpt)₂(tcm)₂]（1），其中abpt（4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole，即4-氨基-3,5-双(2-吡啶基)-1,2,4-三唑）、tcm（tricyanomethanide anion，即三氰基甲烷根阴离子），该配合物展现出具有能垒U=86.2 K的场诱导磁慢弛豫行为，且具备较大的轴向与菱面单离子零场分裂参数：D=+48(2) cm⁻¹、E/D=0.27(2)（通过从头算CASSCF/NEVPT2计算得到的结果为D=+53.7 cm⁻¹、E/D=0.29），因此该配合物为一类具有横向磁各向异性的场诱导单离子磁体的全新范例。