這是一份關於吡咯（Pyrrole）及嘧啶（Pyrimidine）在銅（100）和氧/銅（100）表面的熱反應研究。利用程式控溫反應譜（TPR/D）偵測反應脫附的氣體分子，配合反射式紅外線吸收光譜（RAIRS）及X射線光電子光譜（XPS）對表面的吸附物種探測，結合理論計算，分析Pyrrole和Pyrimidine在Cu(100)和O/Cu(100)表面可能的反應路徑。
Pyrrole在Cu(100)表面上，己知不會反應分解。當Pyrrole在140 K於O/Cu(100)表面吸附時，會進行去質子化反應，發生N-H鍵斷裂並且生成OH(ad)和Pyrrolate。理論計算此反應的活化能為6.02 kcal/mol，約在100 K左右即可發生反應。Pyrrolate在250 K會進一步反應發生環結構改變或是環破裂，並且在350 K時完全分解生成其他物種。當溫度繼續提高，會脫氫持續產生H2O脫附。在600 K時，表面的中間產物會再分解出CO2和H2O。在700K，表面有足夠的O(ad)濃度，會產生CO2脫附，致使在850 K左右有N2的生成脫附。若表面O(ad)濃度不足，則在770 K左右分解產生HCN及H2，並且在850 K以上生成C2N2。另外在600 K有大量的H2O生成脫附，會導致HCN和H2的生成會減少，甚至不會產生H2。然而在高暴露量的紅外線光譜中，在500 – 700 K有789 cm-1的吸收峰出現，顯示在不同的覆蓋率可能造成Pyrrole在O/Cu(100)表面有不同的反應路徑或生成物。
Pyrimidine在140 K於Cu(100)及O/Cu(100)表面吸附時，不會發生反應分解，而且隨溫度提高只有發生脫附。在紅外線光譜中，在這兩種表面也只有觀察到in-plane的吸收峰，顯示Pyrimidine在表面有直立或是接近直立的吸附。理論計算Pyrimidine在Cu(100)或O/Cu(100)最穩定的吸附結構結果也顯示，Pyrimidine分子和表面之間有N－Cu鍵生成且分子直立於表面。此結果也與紅外線研究相符。另外，在Cu(100)的高暴露量紅外線光譜中，在140 K有不在Pyrimidine振動模式中的吸收峰生成。

The adsorption and thermal chemistry of pyrrole and pyrimidine on Cu(100) and O/Cu(100) have been investigated, using by temperature-programmed reaction/desorption (TPR/D), reflection-adsorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) the calculations for the adsorption energy, structure and orientation and the reaction pathway.
Pyrrole on O/Cu(100) shows a complex reaction. At 140 K, pyrrole decomposes into pyrrolate and OH groups on the surface. The activation energy of this reaction is calculated to be 6.02 kcal/mole. It suggests this reaction can occur even at 100 K. Between 200 K and 350 K, the RAIRS and XPS results indicate that the pyrrolate may have a change in adsorption structure. At higher temperatures, the product of H2O(400, 500, 600 K ), CO2(600, 700 K), H2(770 K) ,HCN( 770 K), N2 (870 K)and C2N2( > 850 K) are detected. The appearing temperatures and relative amounts of these products are dependent on the pyrrole coverage.
Pyrimidine has no reaction on Cu(100) or O/Cu(100) surface. In the IR spectra, only the in-plane vibrational modes are observed. These results reveal the adsorption orientation of the pyrimidine on Cu(100) and O/Cu(100), i.e., are upright or near upright. Theoretically, the pyrimidine is predicted to be adsorbed vertically on Cu(100), with one of the nitrogen atoms on a atop site. The calculated, the most stable geometric structure of pyrimidine/Cu(100) is consistent with the infrared result.
Keywords: Pyrrole, Pyrimidine, Cu(100), temperature-programmed reaction/desorption (TPR/D), reflection-absorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS)

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