Hydrogen-bonding interactions, geometrical selectivity and spectroscopic properties of cobalt(III) complexes with unsymmetrical tridentate amine-amidato-phenolato type ligands
Hydrogen-bonding interactions, geometrical selectivity and spectroscopic properties of cobalt(III) complexes with unsymmetrical tridentate amine-amidato-phenolato type ligands
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DOI：
10.1016/j.ica.2013.01.011
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发表时间：
2013-04-01
影响因子：
2.8
通讯作者：
Kojima, Masaaki
中科院分区：
文献类型：
--
作者：
Mitsuhashi, Ryoji;Suzuki, Takayoshi;Kojima, Masaaki
合成了四种含[Co(Ln)(2)]三齿胺-氨基-酚型配体（Ln: n = 1-4）的钴（III）配合物。所有配合物均通过H-1核磁共振光谱和x射线分析进行了表征。几何选择性取决于胺-氨基螯合物与平面2-氧苄胺6元螯合物结合时的柔韧性；即氨基- 5元螯合物为mer型几何，6元螯合物为面型几何。在大多数聚合物型配合物中，分子间的双氢键是通过氨基和氨基选择性地在单核配合物对映体对之间形成的。对于两个手性配体{L2(2) = 2-氨基-1-（2-氧苄胺）丙烷；[Co(L3)(2)]具有非对映选择性，而[Co(L2)(2)]不具有非对映选择性。此外，PPh4[Co(L1)(2)] (L1（2) = 2-氨基-1-（2-氧苄胺）-2-甲基丙烷）在几种溶剂中表现出明显的溶剂致变色行为。虽然[Co(L2或L3)(2)]的分子结构与[Co(L1)(2)]非常相似，但这些配合物并没有表现出这样的溶剂致变色行为。(C) 2013 Elsevier B.V.版权所有
Four cobalt(III) complexes with the formula of [Co(Ln)(2)] bearing tridentate amine-amidato-phenolato-type ligands (Ln: n = 1-4) were synthesized. All of the complexes were characterized by H-1 NMR spectroscopy and X-ray analysis. The geometrical selectivity was found to depend on the flexibility of the amine-amidato chelate in combination with the planar 2-oxybenzamido 6-membered chelate; that is, the amine-amidato 5-membered chelate took the mer-type geometry, and the 6-membered chelate took the fac-type geometry. In most of the mer-type complexes, intermolecular double hydrogen bonds via amidato(O) and amino group were selectively formed between their enantiomeric pairs of mononuclear complexes. In the case of two chiral ligands {L2(2) = 2-amino-1-(2-oxybenzamido) propane; L3(2) = trans-1-amino-2-(2-oxybenzamido)cyclohexane}, [Co(L3)(2)] showed diastereoselectivity while [Co(L2)(2)] did not. Furthermore, PPh4[Co(L1)(2)] (L1(2) = 2-amino-1-(2-oxybenzamido)-2-methylpropane) showed an apparent solvatochromic behavior in several solvents. Although the molecular structures of [Co(L2 or L3)(2)] are quite similar to that of [Co(L1)(2)] , these complexes did not exhibit such a solvatochromic behavior. (C) 2013 Elsevier B.V. All rights reserved.