A combined Fourier transform infrared (FTIR) spectra of ferrocene (Fc) and density functional theory (DFT) based quantum mechanical calculations confirmed the dominance of the eclipsed Fc conformer in the fingerprint region of 400–500 cm⁻¹ in solutions. Solution IR spectra of Fc measured in acetonitrile (ACN, ε = 35.69), dichloromethane (DCM, ε = 8.93), tetrahydrofuran (THF, ε = 7.43) and dioxane (DOX, ε = 2.21) show two well-defined bands in the 480-500 cm⁻¹ region with the higher-wavenumber band higher in intensity. The band profile agrees well with the earlier IR spectra of Lippincott and Nelson (1958) in tetrachloromethane solution as well as more recent measurement in dichloromethane solution of Duhović and Diaconescu (2013). DFT based quantum mechanical calculations predict that the eclipsed (D_5h) Fc conformer is lower in energy than the staggered (D_5d) conformer and that the room-temperature solution spectrum of Fc is dominated by that of the D_5h form (Best et al., 2016). The present study confirms that solvent effects enhanced the dominance of the D_5h Fc conformer which resulted in switch of the IR profile patterns in 400–500 cm⁻¹, from low-wavenumber band higher in intensity pattern in gas phase to higher-wavenumber band higher in intensity in solutions. It further suggests that the effects of solvents on the IR spectra of Fc in this region are small and the solvent model effects are also small for the IR spectrum in the region of 400–500 cm⁻¹ of Fc.

二茂铁 (Fc) 的傅立叶变换红外 (FTIR) 光谱和基于密度泛函理论 (DFT) 的量子力学计算的组合证实了在溶液中 400–500 cm ^-1指纹区域中失色 Fc 构象异构体的优势。在乙腈 (ACN, ε = 35.69)、二氯甲烷 (DCM, ε = 8.93)、四氢呋喃 (THF, ε = 7.43) 和二恶烷 (DOX, ε = 2.21) 中测量的 Fc 溶液 IR 光谱在480-500 厘米^-1具有较高波数带的区域强度较高。谱带轮廓与 Lippincott 和 Nelson (1958) 在四氯甲烷溶液中的早期红外光谱以及 Duhović 和 Diaconescu (2013) 在二氯甲烷溶液中的最新测量结果非常吻合。基于 DFT 的量子力学计算预测，遮蔽 (D _5h ) Fc 构象异构体的能量低于交错 (D _5d ) 构象异构体，并且 Fc 的室温溶液光谱以 D _5h形式的光谱为主（Best 等人., 2016)。本研究证实，溶剂效应增强了 D _5h Fc 构象异构体的优势，导致 400-500 cm ^-1的 IR 分布模式转换，从气相中强度模式较高的低波数带到溶液中强度较高的高波数带。这进一步表明，溶剂对该区域 Fc 的 IR 光谱的影响很小，并且溶剂模型对 Fc 400-500 cm ^-1区域内的 IR 光谱的影响也很小。