透過您的圖書館登入
IP:3.226.254.255
  • 學位論文

甲基吡啶萘啶胺配基及其三核、六核及九核金屬串錯合物之合成與研究

Syntheses and Studies of Tri-, Hexa-, Nona-nuclear Metal String Complexes with the Hbmpa, H2bmpany and H3bmpanya Ligands

指導教授 : 彭旭明

摘要


本論文是探討含甲基吡啶與萘啶官能基的一系列配基:二甲基吡啶胺(Bis(4-methyl-2-pyridyl)amine, Hbmpa),2,7-二甲基吡啶胺-1,8-萘啶(2,7-bis(4-methyl-2-pyridylamino)-1,8-naphthyridine, H2bmpany)與N,N-二甲基吡啶胺萘啶胺(N,N-bis (4-methyl-2-pyridylamino-1,8- naphthyridyl)amine, H3bmpanya)的配位化學研究,我們成功的合成這些配基,也經由1H NMR、FAB-MS與元素分析鑑定這些配基。 在三氮配基的研究中,我們已經成功合成Ni3(bmpa)4(NCS)2與Co3(bmpa)4(NCS)2,並且已經成功得到其晶體結構,三核鎳錯合物為對稱的結構,Ni…Ni的距離為2.442(1)Å;三核鈷錯合物也屬於對稱的結構,Co-Co的鍵長約為2.320(1) Å。電化學的量測可知三核鎳錯合物僅在E1/2(ox) = + 1.02 V的位置具有一對氧化還原對,而三核鈷錯合物則是在E1/2(ox) = + 0.31 V的位置具有一對可逆的氧化還原對。 在六氮配基的方面,我們也成功合成[Ni6(bmpany)4(NCS)2](PF6)n , n= 1, 2以及[Co6(bmpany)4(NCS)2](PF6)n , n= 1, 2, 3,並且已成功得到晶體結構;[Ni6(bmpany)4(NCS)2] (PF6)2的結構為四個bmpany2-配基纏繞於金屬串上,六個鎳金屬的排列近乎直線,不考慮軸配位基時,錯合物具D4對稱,而其鎳與鎳之間並無鍵結,末端的兩個鎳金屬為四角錐環境,高自旋態(S = 1),而內部四個鎳(II)為平方四邊形環境,低自旋態(S = 0)。還原一個電子的 [Ni6(bmpany)4(NCS)2] (PF6)1也有相似的結構,但是它的金屬軸卻由Ni612+還原為Ni611+。還原前後萘啶配位部分的鎳-鎳距離由2.299(2) Å明顯的縮短至2.224(3) Å,而鎳-氮(萘啶)的鍵長則從1.887(8) Å明顯的變長為,所以我們推測一個電子的還原發生在與萘啶配位的鎳金屬上。六核鎳錯合物的電化學方面共具有四組氧化還原對,分別是E1/2(red1)=-0.2V,E1/2(red2)=-0.53V,E1/2(red3)=-0.84V,E1/2(ox)=+1.09V,由電化學的性質來看我們較容易得到未氧化還原(Ni612+)與還原一個電子(Ni611+)的六核鎳錯合物。在六核鈷錯合物方面,具有四組氧化還原對分別為E1/2(ox1) =+0.27V,E1/2(ox2) =+0.81V,E1/2(ox3) =+1.08V,E1/2(red) =-0.66V,由電化學性質來判斷,可分離出還原一個電子的(Co611+)、未氧化還原的(Co612+)和氧化一個電子(Co613+)的六核鈷金屬錯合物。在六核鈷金屬錯合物的磁性方面,還原一個電子的Co611+於300K之有效磁矩為1.87 μB,為S = 1/2之電子組態:而未氧化還原的Co612+於300K之有效磁矩為2.82 μB,較符合為S = 1的電子組態,而氧化一個電子的Co613+於300K之有效磁矩為3.63 μB,符合為S = 3/2的電子組態。 在九氮配基方面,我們成功合成[Ni9(bmpanya)4(NCS)2]Xn , n= 2, 3及目前世界上最長的鈷金屬串,[Co9(bmpanya)4(NCS)2] (PF6)n , n= 3,並成功得到晶體結構,電化學方面,九核鎳錯合物具五組氧化還原對分別是E1/2(ox1) =+0.1V,E1/2(ox2) =+0.94V,E1/2(ox3) =+1.37 V,E1/2(red1)=-0.17V,E1/2(red2)=-0.47V,磁性上,[Ni9(N9Me2)4(NCS)2]2+在300K的有效磁矩為4.88 μB,與純自旋理論磁矩末端為S = 1,而萘啶單元為S = 1/2所計算之理論磁矩為4.69μB符合。而在九核鈷金屬錯合物方面,目前也順利合成九核鈷金屬串錯合物及其晶體,但結構中為九核與八核鈷金屬串失序情形組合而成,Co(1)到Co(9)的距離約為18 Å左右,是目前文獻記載中最長的鈷金屬串錯合物。電化學方面,九核金屬串具有兩組氧化還原對位於E1/2(ox1)=+0.12V,E1/2(ox2) =+0.83 V,八核鈷金屬串具有四組氧化還原對位於E1/2(red1) =-0.56V,E1/2(ox1)=+0.44V,E1/2(ox2)=+0.64V,E1/2(ox3)=+1.06V。

關鍵字

金屬串 導電度 磁性 奈米材料 分子開關

並列摘要


We report novel series ligands containing picolyl and naphthyridyl group , Bis(4-methyl-2-pyridyl)amine, Hbmpa, 2,7-bis(4-methyl-2-pyridylamino)-1,8-naph- thyridine, H2bmpany, N,N-bis(4-methyl-2-pyrid-yl-amino-1,8-naphthyridyl)amine, H3bmpanya, these ligands are characterized by 1H NMR、FAB-MS and element analysis. The ligand Hbmpa has been used to synthesize trinuclear nickel and cobalt complexes, the X-ray structures reveal the trinuclear nickel string complex has a symmetric structure, the Ni…Ni distance is 2.4415(11) Å, the trinuclear cobalt string complex also has a symmetric structure, the Co-Co bond distance is ca. 2.3204(4) Å, The electrochemistry displays both one redox couple of the nickel and cobalt complexs at + 1.02 V and + 0.31 V, respectively. The hexanuclear nickel and cobalt string complexes can be synthesized by the ligand H2bmpany, and we succeed to get the structures of [Ni6(bmpany)4(NCS)2](PF6)n, n = 1, 2 and [Co6(bmpany)4 (NCS)2](PF6)n, n = 1, 2, 3, in Ni system, Ni6 complexes have linear cores of metal arrangements with D4 symmetry but without any metal-metal bonding, For both n=1 and 2 of Ni6, the terminal nickel(II) ions are high-spin states (S = 1), in the n = 2 case, the inner four nickels(II) ions are in low-spin states (S = 0) but in the n = 1 case, the inner dinickel ions bonded with naphthyridly part are in S = 1/2 state. In the one electron reduction of Ni6 complex, the Ni(3)-Ni(4) distance are slight shorter from 2.299(2) Å to 2.224(3) Å. The Ni(3)-Npy(av) distance obviously becomes longer from 1.887(8) Å to 2.006(4) Å. We propose reduction was occurred at one unit of Ni(3) and Ni(4). In Co system, the electrochemistry of Co6 complexes displays four redox couples at E1/2(red1) = -0.2V,E1/2(red2) = -0.53V,E1/2(red3) = -0.84V,E1/2(ox) = +1.09V, repectively. One electron reduced complex (n= 1) is stable in air, it has +1.83 averaged oxidation state, and exhibits magnetic moment as 1.87μB (300K), the magnetic moment of the n= 2 complex is 2.82μB (300K) consistent with (S = 1), the one electron oxidized complex (n = 3) exhibits magnetic moment as 3.63μB(300K) consistent with (S = 3/2). The EHMO calculation shows that three unpaired electrons were filled in δ*(5), σ*(4) and δ*(6). Nonanuclear nickel and cobalt string complexes are synthesized with H3bmpanya ligand. In nickel system, the electrochemistry of Ni9 complexes displays five redox couples at E1/2(red1) = -0.17V,E1/2(red2) = -0.47V, E1/2(ox1) = +0.1V,E1/2(ox2) = +0.94V and E1/2(ox3) = +1.37V, repectively. The magnetic moment of [Ni9(N9Me2)4(NCS)2]2+ is 4.88μB (300K) and consistent with terminal nickel(II) ions are high-spin states (S=1), the inner Ni(3)-Ni (4) and Ni (6)-Ni (7) are in S=1/2 state. In cobalt system, Co9 chain is the longest Co chain obtained up to date with direct Co-Co bonds. However, structurally the Co9 and Co8 complexes are mixed, we can not separate them yet.

參考文獻


15. Kuo, C. K.; Chang, J. C.; Yeh, C. Y.; Lee, G. H.; Wang, C. C.; Peng, S. M.; Dalton Trans., 2005, 3696-3701.
31. Cotton, F. A.; Daniels, L. M.; Lu, T. B.; Murillo, C. A.; Wang, X.; J. Chem. Soc.-Dalton Trans., 1999, 517.
37. Peng, C. H.; Wang, C. C.; Lee, H. C.; Lo, W. C.; Lee, G. H.; Peng, S. M.; J. Chin. Chem. Soc., 2001, 48, 987.
34. Yang, M. H.; Lin, T. W.; Chou, C. C.; Lee, H. C.; Chang, H. C.; Lee, G. H.; Leung, M. K.; Peng, S. M.; Chem. Commu., 1997, 2279.
32. Cotton, F. A.; Daniels, L. M.; Murillo, C. A.; Wang, X.; Chem. Commun., 1999, 2461.

被引用紀錄


林耿民(2016)。微調二吡啶萘啶二胺配基及其直線型多核金屬串分子之合成與研究〔博士論文,國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342%2fNTU201610301
陳奕安(2014)。三吡啶二胺配基之四核異金屬(鈷/鎢及鎳/鉬)串錯合物的合成及研究〔碩士論文,國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342%2fNTU.2014.03145

延伸閱讀