Synthesis, structure and magnetism of homodinuclear complexes of Co, Ni and Cu supported by a novel bitriazine scaffold
作者:Derek J. Reid、John E. W. Cull、Kimberley D. S. Chisholm、Alexandre Langlois、Po-Heng Lin、Jérôme Long、Olivier Lebel、Ilia Korobkov、Ruiyao Wang、James D. Wuest、Muralee Murugesu、Jennifer Scott
DOI:10.1039/c1dt00018g
日期:——
Btzn (1), an amine-functionalized bi(1,3,5-triazine) 4,4′-(NH2)2-6,6′-(NHC6H5)2-2,2′-(1,3,5-C3N3)2, is reported, and its coordination with Co, Ni and Cu is explored. Reactions of metal salts (2 equiv) with Btzn (1 equiv) result in dimeric species [(Btzn)Co2(NCS)4(EtOH)2(DMF)2], (2), [(Btzn)Ni2(η1-ONO2)2(MeOH)4(DMF)2]·2[NO3], (3), [(Btzn)Cu2Cl4(DMF)2], (4), and [(Btzn)Cu2(η2-O2NO)2(OH2)2(DMF)2]·2[NO3], (5). These complexes are the first examples of the coordination of transition metals with bi(1,3,5-triazine) ligands. Their structures display a bridging bis-bidentate coordination mode for Btzn. Variable-temperature magnetic susceptibility of the complexes reveals antiferromagnetic exchange between the spin carriers, with calculated exchange coupling values (J) of −4.7 cm−1 for 3, −18.2 cm−1 for 4, and −5.5 cm−1 for 5. An in-depth evaluation of the metal geometry highlights the inefficient overlap of the magnetic d-orbitals through the bridging ligand, most likely leading to reduced delocalization and coupling.
报告了胺功能化双(1,3,5-三嗪)4,4′-(NH2)2-6,6′-(NHC6H5)2-2,2′-(1,3,5-C3N3)2 的 Btzn (1),并探讨了它与 Co、Ni 和 Cu 的配位。金属盐(2 等份)与 Btzn(1 等份)反应生成二聚物[(Btzn)Co2(NCS)4(EtOH)2(DMF)2],(2)、(Btzn)Ni2(η1-ONO2)2(MeOH)4(DMF)2]-2[NO3],(3),[(Btzn)Cu2Cl4(DMF)2],(4) 和 [(Btzn)Cu2(η2-O2NO)2(OH2)2(DMF)2]-2[NO3],(5)。这些配合物是过渡金属与双(1,3,5-三嗪)配体配位的首个实例。它们的结构显示了 Btzn 的桥式双同位配位模式。这些配合物的变温磁感应强度显示了自旋载流子之间的反铁磁交换,计算得出的交换耦合值 (J) 分别为:3 为 -4.7 cm-1、4 为 -18.2 cm-1 和 5 为 -5.5 cm-1。对金属几何形状的深入评估突出表明,通过桥接配体,磁性 d 轨道的重叠效率很低,这很可能导致脱ocalization 和耦合的降低。