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Design, synthesis and characterization of paramagnetic complexes based on thiazyl radicals.

机译：基于噻唑基自由基的顺磁性配合物的设计，合成和表征。

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摘要

Paramagnetic complexes based on the 4-(2'-pyrimidyl)-1,2,3,5-dithiadiazolyl radical as a bridging spin-bearing ligand have been exclusively studied in this thesis. The goal was to investigate the magnetic exchange interaction between transition metal ions and the radical ligand. We designed and synthesized transition metal complexes bridged by the 4-(2'-pyrimidyl)-1,2,3,5-dithiadiazolyl radical ligand with bis-bidentate N-coordination mode. The ligands and the complexes have been characterized by FT-IR, EPR, cyclic voltammetry, X-ray crystallography, etc. The SQUID (Superconducting Quantum Interference Devices) magnetometry measurements showed that the design goals were achieved. The complexes are the first bis-bidentate N-coordination compounds reported for a 1,2,3,5-dithiadiazolyl radical.;Complexes with bis-bidentate coordination modes provide a good platform for the study of intra-molecular magnetic exchange interaction. Two transition metal ions bridged by a spin bearing ligand construct a rigid geometry, and a direct consequence of this coordination mode is the direct exchange interaction between metal ions and radical. This results in the two metals being forced into ferromagnetic coupling with one another, in other words, an overall ferro- or ferri-magnetic coupling scheme. Therefore, regardless of the nature of the magnetic coupling between the ligand and the metal, an optimum total spin quantum number is always guaranteed.;Inter-molecular magnetic exchange interaction was also studied by coordinating only one metal ion to the 4-(2'-pyrimidyl)-1,2,3,5-dithiadiazolyl radical, leaving the remaining coordination site unoccupied. The complexes of this type of coordination, called herein mono-metal complexes, usually crystallize with dimerization of adjacent 1,2,3,5-dithiadiazolyl rings on neighboring complexes. Consequently, magnetic coupling of the ligand with a coordinated transition metal ion is not observed in the solid state. However, an unusual crystalline material consisting of mono-Mn complex packed in a "zigzag" structure was obtained, which has not been reported anywhere in the literature.;In this thesis a series of neutral radicals was prepared, among them 4-(2'-pyrimidyl)-1,2,3,5-dithiadiazolyl radical and 3,5-bipyridyl-1,2,4,6-thiatriazinyl radical were unknown prior to our research. The 4-(2'-pyrimidyl)-1,2,3,5-dithiadiazolyl radical has been fully investigated and coordinated to transition metal complexes. The designed objective has been achieved. We have also successfully synthesized the 3,5-bipyridyl-1,2,4,6-thiatriazinyl (TTA) radical. Due to this TTA radical's highly propensity to form the corresponding closed shell imine, perhaps from exposure to moisture, great effort has been taken to avoid moisture in every step of the processes. Difficulty working with this TTA radical has hindered the synthesis of its metal complexes to date.
机译：本文以4-（2'-嘧啶基）-1,2,3,5-二硫二唑基为桥联自旋配体，研究了顺磁性配合物。目的是研究过渡金属离子与自由基配体之间的磁性交换相互作用。我们设计和合成了过渡金属配合物，由4-（2'-嘧啶基）-1,2,3,5-二噻二唑基自由基配体与双双齿N-配位模式桥接。通过FT-IR，EPR，循环伏安法，X射线晶体学等方法对配体和配合物进行了表征。SQUID（超导量子干涉仪）磁力测量表明已达到设计目标。该配合物是报道的1,2,3,5-二噻二唑基的首个双齿N-配位化合物。具有双齿配位模式的配合物为分子内磁交换相互作用的研究提供了一个良好的平台。由自旋轴承配体桥接的两个过渡金属离子构成了刚性几何结构，这种配位模式的直接结果是金属离子与自由基之间的直接交换相互作用。这导致两种金属被迫彼此进行铁磁耦合，换言之，整个铁磁或亚铁磁耦合方案。因此，无论配体与金属之间的磁耦合性质如何，总能保证最佳的总自旋量子数。;还通过仅将一种金属离子配位至4-（2' -嘧啶基）-1,2,3,5-二硫二唑基自由基，剩下的协调位点未被占用。这种配位的配合物，在本文中称为单金属配合物，通常在相邻配合物上相邻的1,2,3,5-二硫二唑基环二聚化时结晶。因此，在固态下未观察到配体与配位的过渡金属离子的磁偶合。然而，获得了一种由单锰配合物堆积成“之字形”结构的不寻常晶体材料，这在文献中没有任何报道。；本论文制备了一系列中性自由基，其中4-（2在我们的研究之前，'-嘧啶基）-1,2,3,5-二硫二唑基和3,5-联吡啶基-1,2,4,6-噻三嗪基是未知的。已对4-（2'-嘧啶基）-1,2,3,5-二硫二唑基进行了充分研究并与过渡金属配合物进行了配位。设计目标已实现。我们还成功地合成了3,5-Bipyridyl-1,2,4,6-thiatriazinyl（TTA）自由基。由于这种TTA自由基很容易形成相应的封闭壳亚胺，可能是由于暴露在湿气中，因此已竭尽全力在过程的每个步骤中避免湿气。迄今为止，使用该TTA自由基的困难性阻碍了其金属配合物的合成。

著录项

  • 作者

    Wu, Jian.;

  • 作者单位

    University of Guelph (Canada).;

  • 授予单位 University of Guelph (Canada).;
  • 学科 Chemistry Inorganic.;Chemistry Organic.;Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 196 p.
  • 总页数 196
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 无机化学;有机化学;工程材料学;
  • 关键词

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