Highly symmetrical tetranuclear cluster complexes supported by p-tert-butylsulfonylcalix[4]arene as a cluster-forming ligand
Highly symmetrical tetranuclear cluster complexes supported by p-tert-butylsulfonylcalix[4]arene as a cluster-forming ligand
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DOI：
10.1002/ejic.200501086
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发表时间：
2006-05-08
影响因子：
2.3
通讯作者：
Iki, Nobuhiko
中科院分区：
文献类型：
--
作者：
Kajiwara, Takashi;Kobashi, Takanori;Iki, Nobuhiko
使用四阴离子对叔丁基磺酰基杯[4]芳烃 (L4-) 作为簇形成配体合成方形平面四核簇 [M-4(L)(AcO)(4)(mu(4)-OH)](-) (M = Mn-II、Co-II 和 Ni-II)。三种配合物在晶体学上是同构的，在空间群 Pi 的三斜晶系中结晶。杯[4]芳烃作为四面三齿配体，通过四个苯氧基和四个磺酰氧原子形成四个金属离子的方形排列，进一步通过四个螯合乙酸根离子和一个羟基离子以mu(4)方式桥联，完成每个金属中心的六配位。尽管每个复合物的整个分子在晶体学上是独立的，但该分子是高度对称的，具有位于 mu(4)-OH- 基团上的伪四重轴。四核簇足够稳定，即使在高度稀释的溶液（约10μm）中也能维持核心结构，这通过质谱研究得到证实，然而，桥联乙酸盐很容易被其他羧酸盐螯合物交换形成衍生物，例如[M-4(L)(BzO)(4)(OH)](-)。通过磁化率研究了金属-金属相互作用，结果表明，根据 Ni-O-Ni 的桥接角，Ni-II 配合物中会发生铁磁和反铁磁相互作用。 (c) Wiley-VCH Verlag GmbH & Co.
Square-planar tetranuclear clusters [M-4(L)(AcO)(4)(mu(4)-OH)](-) (M = Mn-II, Co-II, and Ni-II) are synthesized using tetra-anionic p-tert-butylsulfonylcalix[4]arene (L4-) as a cluster-forming ligand. Three complexes are crystallographically isostructural, being crystallized in the triclinic crystal system with space group Pi. The calix[4]arene acts as a tetrakis fac-tridentate ligand through four phenoxo and four sulfonyl oxygen atoms to form square arrangement of four metal ions, which are further bridged by four chelating acetate ions and one hydroxo ion in a mu(4) manner to complete the hexacoordination of each metal center. Although the whole molecule of each complex is crystallographically independent, the molecule is highly symmetrical with a pseudo-four-fold axis lying on the mu(4)-OH- group. The tetranuclear clusters are stable enough to maintain the core structures even in highly dilute solution (approximate to 10 mu m), which was confirmed by mass spectroscopic study, however, bridging acetates were easily exchanged by other carboxylate chelates to form derivatives such as [M-4(L)(BzO)(4)(OH)](-). Metal-metal interactions were investigated by means of magnetic susceptibility, and it was revealed that both ferro- and antiferromagnetic interactions occur in the Ni-II complex depending on the bridging angles of Ni-O-Ni. (c) Wiley-VCH Verlag GmbH & Co.