Three dinuclear copper(II) complexes containing oxamate-based ligands with the chemical formula [Cu(opba)Cu(dap)(H₂O)]·H₂O (1), [Cu(opba)Cu(dap-OH)(H₂O)]·1.5H₂O (2), and [Cu(opba)Cu(en)(H₂O)]·4H₂O (3) in which opba = o-phenylenebis(oxamato), dap = 1,3-diaminopropane, dap-OH = 2-hydroxy-1,3-diaminopropane and en = ethylenediamine have been synthesized and their crystal structures have been determined by single crystal X-ray diffraction. The molecular structures of 1–3 consist of neutral dicopper(II) complexes obtained by the “complex as a ligand” strategy, in which each [Cu(opba)]²⁻ fragment acts as a bidentate ligand towards the copper(II) ion bonded to the amine capping ligands (dap, dap-OH and en) and the two other carbonyl groups are uncoordinated. Variable-temperature magnetic susceptibility measurements of 1–3 in the temperature range of 4–300 K reveal a strong antiferromagnetic coupling between the metal centers through the oxamate bridge with J = −183.5 cm⁻¹ (1), J = −195.8 cm⁻¹ (2), and J = −195.6 cm⁻¹ (3). The fit of the variable-temperature magnetic susceptibility data of 3 revealed that Cu^IICu^II⋯Cu^IICu^II coupling between the dinuclear entities is very weak. In all cases, the Hamiltonian used was H = −JS₁·S₂. DFT calculations based on the broken-symmetry formalism were used to provide further insight and an explanation for the reported behavior.

中文翻译：

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含草酸盐和封闭配体的双核铜（II）配合物：晶体结构，磁性和DFT计算

三种双核铜（II）配合物，含草酸盐基配体，化学式为[Cu（o pba）Cu（dap）（H ₂ O）]·H ₂ O（1），[Cu（o pba）Cu（dap- OH）（H ₂ O）]·1.5H ₂ O（2）和[Cu（o pba）Cu（en）（H ₂ O）]·4H ₂ O（3），其中o pba = o已经合成了-亚苯基双（恶唑），dap ＝ 1，3-二氨基丙烷，dap-OH ＝ 2-羟基-1，3-二氨基丙烷和en ＝乙二胺，并且已经通过单晶X射线衍射确定了它们的晶体结构。1-3的分子结构由中性双铜（II）配合物组成，该配合物是通过“作为配体的配合物”策略获得的，其中每个[Cu（o pba）] ^2-片段均作为铜（II）的双齿配体与胺封端配体（dap，dap-OH和en）键合的离子没有配位。1-3的可变温度磁化率测量在4–300 K的温度范围内，通过草酸盐桥在金属中心之间表现出强反铁磁耦合，其中J = −183.5 cm ^-1（1），J = −195.8 cm ^-1（2），并且J = −195.6厘米^-1（3）。3的变温磁化率数据的拟合表明，双核实体之间的Cu ^II Cu ^II ⋯Cu ^II Cu ^II耦合非常弱。在所有情况下，使用的哈密顿量为H = −JS ₁ ·S ₂。基于破碎对称形式主义的DFT计算用于提供进一步的见解和对所报告行为的解释。