Two Cu₂ and Zn₂ Metallamacrocycles Featuring a Novel Extended π-Conjugated Carbazole Bridge

Two neutral dinuclear metallamacrocycles, [Cu2(hbca)2]·2CHCl3·2H2O (1) and [Zn2(hbca)2]·7H2O (2), have been assembled from reactions of the new rigid carbazole-based ligand H2hbca [N,N‘-bis(2-hydroxobenzylidene)-9H-carbazole-3,6-diamine] with copper(II) or zinc(II) acetate. The extended aromatic ligand spacer is responsible for intermetallic antiferromagnetic exchange, which is rationalized using the spin-polarization formalism with the help of density functional theory calculations.本研究通过新型刚性咔唑基配体H₂hbca（N,N'-双(2-羟基亚苄基)-9H-咔唑-3,6-二胺）与乙酸铜(II)或乙酸锌(II)的配位反应，成功组装得到两种中性双核金属大环配合物：[Cu₂(hbca)₂]·2CHCl₃·2H₂O（1）与[Zn₂(hbca)₂]·7H₂O（2）。该配体的延展芳香间隔基可引发金属间反铁磁交换相互作用，该作用可借助自旋极化形式方法，并结合密度泛函理论（density functional theory）计算实现合理阐释。