High-Energy X-ray Diffraction Study on the Intramolecular Structure of 2-Aminoethanol in the Liquid State

• Published in: Bulletin of the Chemical Society of Japan Vol. 86; no. 1; pp. 99 - 103
• Main Authors: Kameda, Yasuo, Deguchi, Hiroshi, Kubota, Yoshiyuki, Furukawa, Hirotoshi, Yagi, Yasuyuki, Imai, Yoshihiro, Tatsumi, Masahiko, Yamazaki, Noriko, Watari, Noriko, Hirata, Takuya, Matubayasi, Nobuyuki
• Format: Journal Article
• Language: English
• Published: Tokyo The Chemical Society of Japan 2013; Chemical Society of Japan
• Subjects: Bonding; Diffraction; Dihedral angle; Hydrogen bonds; Intramolecular structures; Least squares method; Liquids; X-rays
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.20120222

High-energy X-ray diffraction measurements were carried out for liquid 2-aminoethanol (NH2CH2CH2OH, MEA) in order to obtain direct information on the conformation of MEA in the liquid state, in which competition between intra- and intermolecular hydrogen bonds might occur. Least-squares fitting analysis was applied to the high-Q region of the observed total interference term with excellent statistical accuracies. Independent parameters, the C–C, C–O, and C–N interatomic distances, bond angles, ∠OCC and ∠CCN, and a dihedral angle ∠(NCC)–(CCO), were successfully obtained. It has been concluded that the MEA molecule takes the gauche conformation with the dihedral angle ∠(NCC)–(CCO) = 53(3)°, suggesting the formation of the intramolecular hydrogen bond is dominant in the liquid state.