Three dinuclear copper(II) complexes with pyrazino[2,3-f][4,7]phenanthroline (pap) as bridging ligand have been prepared; [Cu2(pap)(C2O4)2]·5H2O 1, [Cu2(pap)(H2O)7(SO4)]SO4·3H2O 2 and [Cu2(pap)(H2O)3(NO3)3]NO33. These are the first metal complexes of pap which have been characterized by X-ray crystallography and magnetic susceptibility measurements. In 1 the dinuclear complex is intercepted by a mirror plane; the bridging pap and the terminal oxalate ligands are bidentate in the equatorial plane of copper. In addition copper has weak axial interactions to oxygen atoms of oxalate in two neighbouring molecules. In 2 the two crystallograpically independent copper atoms are both six-co-ordinated with bridging pap and water molecules in equatorial positions, the axial positions being occupied by two water molecules or one water molecule and one sulfate oxygen atom, respectively. In 3 the co-ordination geometry of one copper is close to square pyramidal with pap, one nitrate oxygen atom and one water in equatorial positions; another water occupies the apical position. The description of the co-ordination sphere of the other copper is complicated by the presence of disorder in one of the co-ordinated nitrate groups. When considering only the major site of the disordered nitrate, the co-ordination geometry may in a first approximation be described as square pyramidal with a significant trigonal bipyramidal distortion. In the square pyramidal description the two pap nitrogen atoms, one water and one nitrate oxygen constitute the equatorial plane and a nitrate oxygen is situated in apical position. All the co-ordinated nitrate ions have a second weak Cu⋯O interaction. The Cu⋯Cu separations across bridging pap are 6.740 (1), 6.834 (2) and 6.808 Å (3). Variable-temperature susceptibility measurements reveal Curie law behaviour with very weak intramolecular antiferromagnetic coupling in all three compounds, the relevant parameters being J = −1.4 cm−1, g = 2.06 for 1, J = −1.5 cm−1, g = 2.10 for 2, and J = −1.3 cm−1, g = 2.08 for 3 (the Hamiltonian being H = −J SA·SB).
准备了三种二核
铜(II)配合物,使用呫唑并[2,3-f][4,7]
菲啰啉(pap)作为桥联
配体;分别为[Cu2(pap)(
C2O4)2]·5 1、[Cu2(pap)(
H2O)7(SO4)]SO4·3 2 和 [Cu2(pap)( )3(
NO3)3] 。这些是首次通过X射线晶体学和磁化率测量表征的pap
金属配合物。在1中,二核配合物被一个镜面平面截断;桥联的pap和末端的
草酸配体在
铜的赤道平面内是双齿
配体。此外,
铜还与两个相邻分子的
草酸的氧原子存在弱的轴向相互作用。在2中,两种晶体独立的
铜原子都被六个配位,桥联的pap和
水分子处于赤道位置,轴向位置分别被两个
水分子或一个
水分子及一个
硫酸根氧原子占据。在3中,一个
铜的配位几何形状接近于正方体
金字塔,
配体为pap、一个
硝酸根氧原子和一个
水分子位于赤道位置;另一个
水分子位于顶点位置。另一个
铜的配位球的描述因一个配位的
硝酸根
配体的无序出现而变得复杂。当仅考虑无序
硝酸根的主要位点时,配位几何形状可以在初步近似下描述为正方体
金字塔,并存在显著的三角双
金字塔畸变。在正方体
金字塔的描述中,两个pap氮原子、一个
水分子和一个
硝酸根氧原子构成赤道平面,一个
硝酸根氧原子位于顶点位置。所有配位的
硝酸根离子都有第二个弱的Cu⋯O相互作用。通过桥联pap的Cu⋯Cu间隔分别为6.740 Å (1)、6.834 Å (2) 和6.808 Å (3)。可变温的磁化率测量揭示出符合居里定律的行为,在三种化合物中,分子内的抗
铁磁耦合非常弱,相关参数为1中J = −1.4 cm−1,g = 2.06;2中J = −1.5 cm−1,g = 2.10;3中J = −1.3 cm−1,g = 2.08(哈密顿量为H = −J
SA·SB)。