Abstract We studied the interaction of 5-aza[5]helicene and 5-aza[6]helicene with gold nanostructured substrates by SERS spectroscopy and DFT calculations. By comparing Raman and SERS experiments we observe significant changes for the normal modes involving nitrogen. This behavior, together with further evidence coming from SERS experiments carried out on the quaternary salts of the same azahelicenes, clearly highlight the direct interaction of nitrogen with the gold surface. DFT calculations on azahelicene models interacting with Au20 gold clusters reveal the charge transfer between azahelicene and gold. The information obtained from this study is useful in the field of sensor applications, where knowledge of the molecular mechanisms of interaction is fundamental for an appropriate design of the device.

中文翻译：

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氮杂[5]螺旋烯和氮杂[6]螺旋烯与纳米结构金表面相互作用的拉曼和SERS研究

摘要 我们通过SERS 光谱和DFT 计算研究了5-氮杂[5]螺旋烯和5-氮杂[6]螺旋烯与金纳米结构基底的相互作用。通过比较拉曼和 SERS 实验，我们观察到涉及氮的正常模式的显着变化。这种行为，连同来自对相同氮杂螺旋烯的季盐进行的 SERS 实验的进一步证据，清楚地突出了氮与金表面的直接相互作用。氮杂螺旋烯模型与 Au20 金簇相互作用的 DFT 计算揭示了氮杂螺旋烯和金之间的电荷转移。从这项研究中获得的信息在传感器应用领域很有用，其中相互作用的分子机制的知识是适当设计设备的基础。