Synthesis, crystal structure, and magnetic properties of tetraphenylarsonium tetrachloro(oxalato)rhenate(IV) and bis (2,2′-bipyridine)tetrachloro(μ-oxalato)copper(II)rhenium(IV)
Synthesis, crystal structure, and magnetic properties of tetraphenylarsonium tetrachloro(oxalato)rhenate(IV) and bis (2,2′-bipyridine)tetrachloro(μ-oxalato)copper(II)rhenium(IV)
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DOI：
10.1021/ic990376h
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发表时间：
1999-10-18
影响因子：
4.6
通讯作者：
Faus, J
中科院分区：
文献类型：
--
作者：
Chiozzone, R;González, R;Faus, J
合成了两种新的铼（IV）化合物（AsPh4）(2)[ReCl4(ox)](1)和[ReCl4(μ -ox)Cu(bipy)(2)] (2) （AsPh4 =四苯基larsonium阳离子，ox =草酸盐阴离子，bipy = 2,2'-联吡啶），并通过单晶x射线衍射测定了它们的晶体结构。1和2分别在单斜晶系P2(1)/c和P2(1)/n空间群中结晶，a = 22.250(5)埃，b = 11.245(3)埃，c = 19.089(4)埃，β = 96.59(2)度，Z = 4为1，a = 9.421(2)埃，b = 16.909(4)埃，c = 16.179(4)埃，β = 93.97(2)度，Z = 4为2。1的结构是由[ReCl4(ox)]（2-）阴离子和通过静电力结合在一起的AsPh4+阳离子组成的。铼（IV）是六配位的，两个螯合氧原子和四个氯原子围绕金属原子形成一个扭曲的八面体。[ReCl4(ox)]（2-）阴离子之间不发生接触，最短的Re…Re和Cl……Cl距离分别为10.345和7.209埃。这个阴离子配合物通过一个草酸氧与2中的[Cu(bipy)(2)]（2+）阳离子配位，形成中性的异金属双核单元。Cu（II）离子呈现非常扭曲的五配位几何，四个双氮原子位于赤道位置，氧原子位于顶端位置。基面几何向四面体方向扭曲，两个双配体的平均面之间的二面角为37.6(2)度。这些[ReCl4(mu-ox)Cu(bipy)(2)]单元以这样一种方式排列，其中一个氯原子指向相邻的铜原子，形成螺旋链。链内Re - Cu通过氯桥和草桥的距离分别为4.658和4.798埃。在1.8 ~ 300 k的温度范围内，研究了1和2的磁性行为。1是磁性稀释的Re（IV）配合物，在低温范围内，零场分裂的大值（D = 60 cm(-1)）解释了chi(M)T随T的变化。2表现为铁磁链，Re（IV）和Cu（II）之间通过草化桥和单氯桥存在弱反铁磁相互作用。
Two new rhenium(IV) compounds of formula (AsPh4)(2)[ReCl4(ox)] (1) and [ReCl4(mu-ox)Cu(bipy)(2)] (2) (AsPh4 = tetraphenylarsonium cation, ox = oxalate anion, and bipy = 2,2'-bipyridine) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. 1 and 2 crystallize in the monoclinic system, space groups P2(1)/c and P2(1)/n, respectively, with a = 22.250(5) Angstrom, b = 11.245(3) Angstrom, c = 19.089(4) Angstrom, beta = 96.59(2)degrees, and Z = 4 for 1 and a = 9.421(2) Angstrom, b = 16.909(4) Angstrom, c = 16.179(4) Angstrom, beta = 93.97(2)degrees, and Z = 4 for 2. The structure of 1 is made up of [ReCl4(ox)](2-) anions and AsPh4+ cations held united by electrostatic forces. Rhenium(IV) is hexacoordinate, with two oxygens of a chelating ox and four chlorine atoms building a distorted octahedron around the metal atom. There is no contact between the [ReCl4(ox)](2-) anions, the shortest Re ... Re and Cl ... Cl distances being 10.345 and 7.209 Angstrom, respectively. This anionic complex is coordinated to a [Cu(bipy)(2)](2+) cation in 2, through one oxalate-oxygen, giving a neutral heterometallic dinuclear unit. The Cu(II) ion shows a very distorted five-coordinated geometry, four bipy-nitrogens occuping the equatorial positions and the oxygen atom the apical one. The basal plane geometry is distorted toward the tetrahedron, the dihedral angle between the mean planes of the two bipy ligands is 37.6(2)degrees. These [ReCl4(mu-ox)Cu(bipy)(2)] units are arranged in such a way that a chlorine atom of one of them points toward the copper atom of the neighboring one, forming helicoid chains. The intrachain Re Cu distances through chloro and oxalato bridges are 4.658 and 4.798 Angstrom, respectively. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8-300 K. 1 is a magnetically diluted Re(IV) complex, the great value of zero-field splitting of the ground level (D = 60 cm(-1)) accounting for the variation of chi(M)T with T in the low-temperature range. 2 behaves as a ferrimagnetic chain, with weak antiferromagnetic interactions between Re(IV) and Cu(II) through oxalato and single chloro bridges.