This study presents a comprehensive analysis of the vibrational spectra of methyl-β-D-ribofuranoside. Employing a combination of inelastic neutron scattering, Raman, and infrared spectroscopy allows for the observation of all modes regardless of the selection rules. The experimental techniques were complemented by density functional theory computational methods using both gas-phase (Gaussian) and solid-state (CRYSTAL, CASTEP) approaches to provide an unambiguous assignment of the defining vibrational features. Two distinct structures of the molecule were identified in the unit cell, differentiated mainly by the orientation of the furanose ring O–H bonds. The low-energy region of the spectrum (<400 cm^–1) is dominated by lattice vibrations and functional group rotation, while the midenergy region is dominated by out-of-plane bending motions of the furanose ring (400–900 cm^–1) and by C–H bending in the methyl and methylene groups (1400–1600 cm^–1). The high-energy region (>2800 cm^–1) encompasses the C–H and O–H stretching modes and offers convincing evidence of at least one H-bonding interaction between the two structures of methyl-β-D-ribofuranoside.

中文翻译：

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甲基-β-D-呋喃核苷的综合分析：多方面的光谱和理论方法

本研究对甲基-β- D-呋喃核苷的振动光谱进行了全面分析。采用非弹性中子散射、拉曼和红外光谱的组合可以观察所有模式，而不管选择规则如何。实验技术得到密度泛函理论计算方法的补充，使用气相（高斯）和固态（CRYSTAL、CASTEP）方法来提供定义振动特征的明确分配。在晶胞中鉴定出该分子的两种不同结构，主要通过呋喃糖环 O-H 键的方向来区分。光谱的低能区域（<400 cm ^–1）主要由晶格振动和官能团旋转主导，而中能区域则由呋喃糖环的面外弯曲运动（400–900 cm ^–1）以及甲基和亚甲基中的 C–H 弯曲 (1400–1600 cm ^–1 )。高能区域（>2800 cm ^{–1 ）包含 C-H 和 O-H 拉伸模式，并提供了甲基-β-} D-呋喃核苷两个结构之间至少一种氢键相互作用的令人信服的证据。