三吡啶二胺配基(H2tpda)之四核鉬與釕金屬串及新型三核鎳金屬串的合成與研究

Abstract

本論文研究的內容可分為兩部分，第一部分為不對稱5-苯基吡啶噻唑胺(Hphpta= 5-phenylpyridinyl-thiazolylamine)配基之金屬串研究。將Hphtpa與金屬利用傳統萘燒法，在高溫下即可獲得直線型三核金屬串錯合物[Ni3(phpta)4(X)2] (X = Cl, NCS)，金屬串錯合物中三個鎳金屬被四片phpta架橋配基以螺旋的方式環繞而呈現直線型。在X-ray單晶結構中，[Ni3(phpta)4Cl2]存在配基失序的問題，導致噻唑(Thiazole)與吡啶(Pyridine)無法區別。而[Ni3(phpta)4(NCS)2]則沒發生失序問題，結構為(4,0)的構型。由直線三核金屬錯合物分子軌域模型，可以知道Ni-Ni之間沒有金屬-金屬鍵結的存在。磁性方面，350 K下的有效磁矩為3.37 B.M.，呈現反鐵磁曲線。並利用掃描式穿隧顯微破裂接合點法(STM-bj)測量其導電度，值為1.2 × 10-3 (G0)。 第二部分選用三吡啶二胺五氮配基，簡稱H2tpda，利用萘燒法合成出目前已知第一個四核鉬金屬串錯合物[Mo4(tpda)4](PF6)，並獲得其單晶結構。金屬串由四片tpda-配基以(2,2) trans錯位螺旋環繞住四個直線排列的鉬金屬。X-ray單晶結構中發現分子外圍有一個[PF6]-離子，可推知四個鉬金屬共帶有九價正電荷。並藉由磁性測量，得知S = 1/2呈現順磁性的結果。另外，利用H2tpda配基與釕金屬起始物在萘燒法下合成，可順利在電噴灑游離質譜圖中發現[Ru4(tpda)4]+的訊號。

The aim of thesis can be separated in two parts. The first part of thesis is to investigate the tri-nickel metal string complexes which are surrounded by the new type of asymmetric tri-nitrogen ligand, Hphpta (5-phenylpyridinyl-thiazolylamine). The linear tri-nickel complexes, [Ni3(phpta)4(X)2] (X = Cl, NCS),can be synthesized at high temperature by using naphthalene as the solvent. We can find that the tri-metal string complexes are helically wrapped by four phpta- ligands. The X-ray structure shows that [Ni3(phpta)4Cl2] has some trouble of ligand disorder which means that we cannot distinguish between pyridyl and thiazyl parts of phpta-, owing to their similar structure. Luckily, [Ni3(phpta)4(NCS)2] do not face the problem, and we can find that all the thiazyl part of phpta- ligands bind on the same side of the metal string, known as (4,0)-form. There is no metal-metal bond between any two nickels, by qualitative M.O. analysis. Magnetic measurement shows μeff = 3.37 B.M. at 350 K. Furthermore, the conductance value of [Ni3(phpta)4(NCS)2] is around 1.2 × 10-3 (Go), measuring by STM-bj. The second part of my thesis is focus on synthesis the first tetra-molybdenum metal string complex, [Mo4(tpda)4](PF6), which using N5 ligand, H2tpda (tri-pyridyl-di-amine). The X-ray structural studies reveal that four molybdenum metals are chelated by four tpda- ligands and arranged in a straight line. Judging from the [PF6]- anion, we can sure that the total charge of four molybdenum is 9+. Magnetic measurement shows a paramagnetic curve and S = 1/2. Moreover, we could also find the [Ru4(tpda)4]+ signal on ESI-MS spectra by using Ru precursor.