質子化苯二甲胺離子及其類似物於氣相中碰撞誘導解離途徑之探討 = Stud...
國立高雄大學應用化學系碩士班

 

  • 質子化苯二甲胺離子及其類似物於氣相中碰撞誘導解離途徑之探討 = Study on Collision-Induced Dissociation Path of Protonated Xylylenediamine Analogues
  • 紀錄類型: 書目-語言資料,印刷品 : 單行本
    並列題名: Study on Collision-Induced Dissociation Path of Protonated Xylylenediamine Analogues
    作者: 施舜文,
    其他團體作者: 國立高雄大學
    出版地: [高雄市]
    出版者: 撰者;
    出版年: 民100
    面頁冊數: 106葉圖,表格 : 30公分;
    標題: xylylenediamine
    標題: xylylenediamine
    電子資源: http://handle.ncl.edu.tw/11296/ndltd/12879717793203952171
    附註: 參考書目:葉88-93
    摘要註: 以電噴灑游離法(ESI)所生成的離子,經碰撞誘導解離(CID)後所生成的斷片離子,一般大多具有偶數電子。然而,我們的研究發現,質子化m-xylylenediamine離子(MH+)不但在ESI游離源就很容易失去一個氨分子(NH3),形成[MH - NH3]+離子,而且這個偶數電子的離子在較高的碰撞能下,會進一步失去一個氫原子(•H),形成少見的奇數電子離子([MH - NH3 - H•]•+),以及[MH - 2NH3]+等偶數電子的斷片離子。因此,本研究乃比對一些m-xylylenediamine (m-XDA)類似物的一次和二次CID結果,探討其間結構上的差異與生成[MH - NH3]+和[MH - NH3 - H•]•+等斷片離子的關係。分析的化合物可分為(1)具有兩個胺基的m-XDA類似物和(2) m-XDA的結構異構物兩大類,包含的化合物有:o-phenylenediamine、m-phenylenediamine、p-aminobenzylamine、1,3-cyclohexanebis(methylamine)、2,4,6-triethyl-1,3,5-benzenetrimethanamine、o-xylylenediamine和p-xylylenediamine。為瞭解各種化合物於一次和二次CID所生成斷片離子的差異性,進一步以混合式密度泛函理論的UB3LYP/6-311++G(d,p)為計算方法,探討m-XDA及其類似物於不同解離途徑所需的能量。 CID結果顯示,o-XDA的MH+離子因產生內氫鍵,相對於m-XDA和p-XDA不易生成[MH - NH3]+離子;同樣的,phenylenediamine化合物的MH+離子於解離時會破壞苯環的共振結構,也是不易生成[MH - NH3]+離子。至於[MH - NH3 - H•]•+自由基陽離子的生成條件,雖然理論計算預測三種XDA結構異構物生成[MH - NH3 - H•]•+離子所需的能量相近,但CID結果顯示o-XDA並無法生成[MH - NH3 - H•]•+離子,推測o-XDA的前驅物[MH - NH3]+離子中另有作用力,使其較其他結構異構物衍生離子穩定,而我們於理論計算時並未考慮到,造成此差異。另外,理論計算與CID結果的差異,也可能歸因於前者為熱力學產物,而後者為動力學產物。 The even-electron precursor ions usually dissociate into the same state, even-electron, product ions by electrospray ionization tandem mass spectrometry (ESI-MS/MS). We found the protonated m-xylylenediamine (m-XDA) was easily losing NH3 molecule in ESI. However, the [MH - NH3]+ further expelled H atom then forming into radical cations, and lost the another NH3 molecule in the collision cell. We compared with some primary and secondary collision-induced dissociation (CID) results of protonated m-XDA and its analogues to study the relationship between the molecular structure and the formations of [MH - NH3]+ and [MH - NH3 - H•]•+. The m-XDA analogues could be classified by the benzene ring with two amine substituent group and m-XDA regioisomers. MS/MS spectra indicated that the MH+ of o-XDA was harder to dissociate into [MH - NH3]+ than m-XDA and p-XDA because of the internal hydrogen bonding in MH+ of o-XDA; the same, the NH3 dissociation reaction of protonated phenylenediamime would destroy the benzene ring resonance. We also studied the formation conditions of the [MH - NH3 - H•]•+. Although the theory formation energies of the [MH - NH3 - H•]•+ of m-XDA regioisomers were similar, we could not get the [MH - NH3 - H•]•+ fragment of o-XDA by CID. The differences between calculation and CID results were that we did not consider the interaction in [MH - NH3]+ of o-XDA during theoretical calculation processes. Otherwise, the differences could be attributed to the thermodynamics in calculation and the kinetics in CID.
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310002134883 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 421202 0820 2011 一般使用(Normal) 在架 0
310002134875 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 421202 0820 2011 c.2 一般使用(Normal) 在架 0
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