Liu Yuemin, Massoud Salah S, Starovoytov Oleg N, Altalhi Tariq, Gao Yunxiang, Yakobson Boris I
Department of Chemistry, Prairie View A&M University, Prairie View, TX 77446, USA.
Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA.
Nanomaterials (Basel). 2025 Jun 17;15(12):938. doi: 10.3390/nano15120938.
Co(II) complexes have shown promising applications as single-molecule magnets (SMMs) in quantum computing and structural biology. Deciphering the Co(II) complexes may facilitate the development of SMM materials. Structural optimizations and calculations of chemical and magnetic properties were performed for Co(II) complexes with a tripodal tetradentate phenolate-amine ligand using MP2/aug-cc-pvdz, MP2/Def2svp, and CASSCF/Def2svp methods. The Second Order Perturbation Theory Analysis of Fock Matrix in NBO Basis unravels that Co(II) ions form unusual coordinate quasi-double bonds with ligand oxygen donor atoms, and the bond strengths range from 142.01 kcal/mol to 167.36 kcal/mol but lack further spectrometric evidence. The average 151.70 kcal/mol of the Co(II-O coordinates quasi-double bonds are formed mainly by two lone pairs of electrons from the ligand phenolate donor oxygen atoms. Dispersion forces contribute 24%, 28%, 27%, and 31% to the Co(II)-ligand interaction. Theoretical results of ZFS D, transversal ZFS E, and g-factor agree well with the experimental values. Magnetic susceptibility parameters calculated based on 5 doublet roots account for 85% of results computed 40 doublet roots are specified. These insights may aid in the rational design of SMM materials and Co(II) porphyrin fullerene conjugate for CO electroreduction with superior magnetic properties.
钴（II）配合物在量子计算和结构生物学中作为单分子磁体（SMMs）已显示出有前景的应用。解析钴（II）配合物可能有助于单分子磁体材料的发展。使用MP2/aug-cc-pvdz、MP2/Def2svp和CASSCF/Def2svp方法对具有三脚架四齿酚盐-胺配体的钴（II）配合物进行了结构优化以及化学和磁性性质的计算。在自然键轨道（NBO）基组下对福克矩阵进行的二阶微扰理论分析表明，钴（II）离子与配体氧供体原子形成了不寻常的配位准双键，键强度范围为142.01千卡/摩尔至167.36千卡/摩尔，但缺乏进一步的光谱学证据。钴（II）-氧配位准双键的平均键能为151.70千卡/摩尔，主要由配体酚盐供体氧原子的两对孤对电子形成。色散力对钴（II）-配体相互作用的贡献分别为24%、28%、27%和31%。零场分裂D、横向零场分裂E和g因子的理论结果与实验值吻合良好。基于5个双重态根计算的磁化率参数占指定40个双重态根计算结果的85%。这些见解可能有助于合理设计具有优异磁性的用于CO电还原的单分子磁体材料和钴（II）卟啉富勒烯共轭物。
