Syntheses, crystal structures and magnetic properties of polynuclear 1,4,5,8,9,12-hexaazatriphenylene (hat)-bridged copper(II) complexes
Syntheses, crystal structures and magnetic properties of polynuclear 1,4,5,8,9,12-hexaazatriphenylene (hat)-bridged copper(II) complexes
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DOI：
10.1039/b009647o
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发表时间：
2001-01-01
期刊：
影响因子：
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通讯作者：
Lloret, F
中科院分区：
文献类型：
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作者：
Grove, H;Sletten, J;Lloret, F
制备了三种含有铜(II)和1,4,5,8,9,12-六氮杂苯并菲(hat)作为基本结构单元的多核化合物[Cu-4(hat)(2)Cl-8](n)。 6nH(2)O 1、[Cu(hat)(H2O)(2)](n)[NO3](2n) 2 和[Cu-2(hat)(H2O)(6)](n)[SO4](2n)。 2nH(2)O 3，确定了它们的晶体结构并测量了变温磁化率数据。 1 中的基本构建块是双核 [Cu-2(hat)Cl-4] 实体，两个这样的单元通过相对较强的轴向 Cu-Cl 键（面外二-μ-氯桥）连接到四核单元。轴向铜较弱。 。 。 Cl 相互作用将单元连接成片状结构。在2和3中，存在沿滑移面延伸的帽桥铜(II)链。 hat在2中充当双齿配体并在3中充当三齿配体；在后一种化合物中，与帽子配位的铜原子之一不参与链的形成。在这些化合物中观察到的铜配位几何形状是方锥体和细长八面体。 hat 仅在赤道位置与铜配位 (1)，或者与一种螯合物在两个赤道位置和另一种螯合物在一个赤道位置和一个轴向位置交替（2 和 3）。铜。 。 。 1 中帽子桥的铜距离为 6.857(1) 埃，跨越三个不同二-μ-氯桥的铜距离为 3.517(1)、3.600(1) 和 3.651(1) 埃。 2 链内Cu 。 。 。 Cu 距离为 6.797(1) 埃。三种不同的铜。 。 。帽桥上的 Cu 距离为 3，其中 6.789(1) 埃之一涉及跨吡嗪环的两个赤道 Cu-N 键，7.117(1) 和 7.186(1) 埃中的两个涉及吡嗪的一个赤道和一个轴向 Cu-N 键。 1-3的变温磁化率测量揭示了铜(II)离子之间通过桥帽发生弱分子内反铁磁相互作用，J值为-2.5 (1)、-2.1 (2)和-2.4 cm(-1) (3)。在1 中，四核实体(J') 内跨二-μ-氯桥的相互作用被发现较弱且具有铁磁性(约+0.7 cm(-1))。
Three polynuclear compounds containing copper(II) and 1,4,5,8,9,12-hexaazatriphenylene (hat) as the basic building blocks have been prepared, [Cu-4(hat)(2)Cl-8](n). 6nH(2)O 1, [Cu(hat)(H2O)(2)](n)[NO3](2n) 2, and [Cu-2(hat)(H2O)(6)](n)[SO4](2n). 2nH(2)O 3, their crystal structures determined and variable-temperature magnetic susceptibility data measured. The basic building block in 1 is the dinuclear [Cu-2(hat)Cl-4] entity, two such units being connected to tetranuclear units through relatively strong axial Cu-Cl bonds (out-of-plane di-mu -chloro bridges). Weaker axial Cu . . . Cl interactions link the units into a sheet structure. In 2 and 3 hat-bridged copper(II) chains extending along glide planes are present. hat serves as a bis-bidentate ligand in 2 and as a ter-bidentate ligand in 3; in the latter compound one of the copper atoms coordinated to hat does not participate in chain formation. The copper coordination geometries observed in these compounds are square pyramidal and elongated octahedral. hat coordinates either in only equatorial positions to copper (1), or alternates with one chelate in two equatorial positions and another in one equatorial and one axial position (2 and 3). The copper . . . copper distance across the hat bridge in 1 is 6.857(1) Angstrom and 3.517(1), 3.600(1) and 3.651(1) Angstrom across the three different di-mu -chloro bridges. In 2 the intrachain Cu . . . Cu distance is 6.797(1) Angstrom. Three different Cu . . . Cu distances across the hat bridge are found in 3, one of 6.789(1) Angstrom involving two equatorial Cu-N bonds across a pyrazine ring, and two of 7.117(1) and 7.186(1) Angstrom involving one equatorial and one axial Cu-N bond to a pyrazine. Variable-temperature susceptibility measurements on 1-3 reveal the occurrence of weak intramolecular antiferromagnetic interactions between copper(II) ions through bridging hat, the J values being -2.5 (1), -2.1 (2) and -2.4 cm(-1) (3). In 1 the interaction across the di-mu -chloro bridge within the tetranuclear entity (J') is found to be weak and ferromagnetic in character (ca. +0.7 cm(-1)).