Structure and dimensionality of coordination complexes correlated to piperazine conformation: from discrete [CuII2] and [CuII4] complexes to a μ1,3-N3− bridged [CuII2]n chain
摘要两个新的四核CuII配合物[Cu4(L2)2(µ2-OH)2(H2O)2]·(ClO4)2·DMF·2H2O(1)和[Cu4(L3)2(µ2-OH)2(H2O) )2]·(ClO4)2·DMF·H2O(2)已合成,其中包含哌嗪基希夫碱配体H2L2(不对称)和H2L3(对称)。H2L2含有一个邻香兰素和一个水杨醛单元,而H2L3有两个邻香兰素单元。为了合成H 2 L 2和H 2 L 3,已经探索了一种有趣的合成方法,该方法涉及过渡金属离子诱导的两个席夫碱配体之间的醛交换反应。尽管后者可以通过相应的胺和醛直接缩合而获得,但前者只能通过开发的这种方法来合成。1和2均包含哌嗪环,以稀有的轴-赤道配位方式将两个CuII中心连接成椅子构型。两个哌嗪桥连的Cu 2部分还通过两个羟基和两个苯氧基桥连接。在两个Ophenoxido–Cu键中,一个短(基)键,另一个长(顶)键,而羟基O以基-基方式对称地桥
Synthesis and Characterisation of Some Hexadentate Schiff-base Ligands Containing the Piperazine Moiety
作者:Hassan Keypour、Majid Rezaeivala、Ahmad Ali Dehghani-Firouzabadi
DOI:10.3184/030823409x402528
日期:2009.2
Ten hexadentate (N4O2, N4S2 and N6) Schiff-base ligands have been prepared by condensation of various aldehydes and two different linear tetraamines containing the piperazine moiety. The products have been characterised by melting point, elemental analysis and various spectroscopic methods such as: FT-IR, 1H, 13C NMR, and EI mass spectrometry. The complex [CoN, N'-bis[(pyridin-2-ylmethylene)ethyl
十个六齿(N4O2、N4S2 和 N6)席夫碱配体已通过各种醛和两种不同的包含哌嗪部分的线性四胺的缩合制备。产品已通过熔点、元素分析和各种光谱方法进行表征,例如:FT-IR、1H、13C NMR 和 EI 质谱。复合物 [CoN, N'-bis[(pyridin-2-ylmethylene)ethyl]piperazine}][ClO4]2 已制备。
Unique Asymmetric (Cu<sup>II</sup><sub>4</sub>) Double-Stranded Helicate from a Hexadentate Piperazine-Based Ligand: Ligand Conformation Isomerism upon Coordination
作者:Alok Ranjan Paital、Prasant Kumar Nanda、Sunirban Das、Guillem Aromí、Debashis Ray
DOI:10.1021/ic051455y
日期:2006.1.1
constrained piperazine imine phenol ligand (H(2)L), in the presence of NEt(3), affords a novel tetranuclear copper(II) complex of formula [Cu(II)(4)(mu(3)-L)(2)(mu-OH)(2)(H(2)O)(2)](ClO(4))(2).H(2)O (1). The X-ray structure of this complex shows an elongated Cu(4) quasi-tetrahedron coordinated to two hexadentate chair-(e,a)-mu(3)-piperazine bridging ligands. Variable-temperature magnetic studies show an