本研究目標為釐清烷基胺分子之自組裝機制，採「預先吸附」及「動態吸附」兩種實驗方式，藉電化學掃描式電子穿隧顯微鏡(Electrochemical Scanning Tunneling Microscopy, EC-STM)及循環伏安儀進行探討，並操控介面電位與不同自組裝分子濃度修飾Au(111)基板，觀測烷基胺分子於金單晶電極上之吸附行為。於預先吸附實驗觀測中採浸泡10mM分子液方式，分別選用三種碳鏈長度之烷基胺分子：六碳、十二碳、十八碳，自組裝於金基板上。成果中發現烷基胺碳鏈長度將會直接影響其與Au(111)基板間之配位鍵強度，其中六碳烷基胺因碳鏈較其他二者短，烷基群向氮原子推電子效應較弱，無法於STM表面觀測中察得其吸附構型。在十二、十八碳胺之觀測中發現，若分子在中性溶液中預先吸附於Au(111)表面上，即使在強酸環境中仍可以觀測到分子吸附條紋，並不會質子化成R-NH3+狀態並失去配位能力。而於動態吸附實驗觀測中，在不同啟始電位下加入μM濃度量級之長鏈烷基胺分子，將發現完全不同之吸附現象，於此研究結果中推論質子化烷基胺雖因無孤對電子而無法與Au(111)表面形成配位鍵結，但若電極電位緩慢由負(0.1 V)逐漸增至偏正電位(0.6 V)時，可觀察到一分子吸附構型急遽顯現之現象。此現象經X射線光電子能譜驗證，推斷其為質子化烷基胺分子(R-NH3+)在Au(111)表面上吸附並轉化為烷基胺分子(R-NH2)，形成並排臥列之高度規則吸附構型，即使將電極電位逆向調回此結構亦不會消散。另發現此一烷基胺自組裝單分子膜之狀態愈接近「並排臥列」構型時，對Ferrocyanide /Ferricyanide氧化還原對的電化學反應具有良好的電子穿透性。

The interfacial properties between the substrate and the deposited film are the major determinants of film construction. In this study, Cyclic voltammetry (CV) and electrochemical scanning tunneling microscopy (EC-STM) were used to study the alkyl amine molecules self-assembly behavior. This study reveals the R-NH2 molecules will form an adsorption pattern with highly regular “ lie down “ shape on Au(111) surface, even in an extreme acid system (pH = 1), the R-NH2 to gold atom binding will not break, only the outer layer R-NH2 will be protonated to R-NH3+ by acid electrolyte and the appearance of R-NH3+ will change when Au(111) electrode’s potential shifts to negative site. By In-situ method to proceed the in time observation, the study result shows a unique “ transform ” behavior of R-NH3+ to R-NH2 when the Au(111) electrode’s potential shifts to more positive site (0.6~0.8 V) from negative site (0.1V). This transform model was confirmed by EC-STM and X-ray Photoelectron Spectroscopy (XPS), once the R-NH2 adsorption structure is formed, the potential operation will not dismiss this adlayer.

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