Energetics and Vibrational Signatures of Nucleobase Argyrophilic Interactions
Energetics and Vibrational Signatures of Nucleobase Argyrophilic Interactions
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DOI：
10.1021/acsomega.8b01895
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发表时间：
2018-10
期刊：
影响因子：
4.1
通讯作者：
S. Lee;Sarah N. Johnson;Thomas L. Ellington;Nasrin Mirsaleh-Kohan;Gregory S. Tschumper
中科院分区：
文献类型：
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作者：
S. Lee;Sarah N. Johnson;Thomas L. Ellington;Nasrin Mirsaleh-Kohan;Gregory S. Tschumper
本研究研究了嘌呤（腺嘌呤和鸟嘌呤）和嘧啶（胞嘧啶、胸腺嘧啶和尿嘧啶）核碱基与一对银原子 (Ag2) 的相互作用。使用 M06-2X 密度泛函对每个核碱基/Ag2 复合物和相应的分离单体的多个结构进行全面几何优化，该密度泛函具有相关一致的三重 z 基组，并通过所有原子上的扩散函数和 Ag 上的相对论赝势进行增强（aug-cc-pVTZ 代表 H、C、N 和 O，aug-cc-pVTZ-PP 代表 Ag；表示为 aVTZ）。谐波振动频率计算表明，每个优化结构对应于 M06-2X/aVTZ 势能表面上的最小值。比较 Ag2 和每个核碱基之间相互作用的相对电子能，以阐明异构体之间的能量差异。对振动频率、红外强度和拉曼散射活性变化的进一步分析揭示了如何通过光谱来区分不同的 Ag2 结合位点。这些结果提供了对核碱基和银之间相互作用的分子水平洞察，这可能有助于更好地理解和解释核碱基和相关系统的表面增强拉曼光谱实验。
This study investigates the interactions of both purine (adenine and guanine) and pyrimidine (cytosine, thymine, and uracil) nucleobases with a pair of silver atoms (Ag2). Full geometry optimizations were performed on several structures of each nucleobase/Ag2 complex and the corresponding isolated monomers using the M06-2X density functional with a correlation consistent triple-ζ basis set augmented with diffuse functions on all atoms and a relativistic pseudopotential on Ag (aug-cc-pVTZ for H, C, N, and O and aug-cc-pVTZ-PP for Ag; denoted aVTZ). Harmonic vibrational frequency computations indicate that each optimized structure corresponds to a minimum on the M06-2X/aVTZ potential energy surface. Relative electronic energies for interactions between Ag2 and each nucleobase were compared to elucidate energetic differences between isomers. Further analysis of the changes in vibrational frequencies, infrared intensities, and Raman scattering activities reveals how different Ag2 binding sites might be differentiated spectroscopically. These results provide molecular-level insight into the interactions between nucleobases and silver, which may lead to better understanding and interpretation of surface-enhanced Raman spectroscopy experiments on nucleobases and related systems.