Accurate measurement of the optical activity of alanine crystals and the determination of their absolute chirality

Published: 22-01-2017| Version 1 | DOI: 10.17632/wwg5snsnbb.1
Contributors:
Kazuhiko Ishikawa,
Yukana Terasawa,
Masahito Tanaka,
Toru Asahi

Description

Figure 1 The absolute structure of the L-alanine crystal. Views of the planes perpendicular to the a-axis (a), b-axis (b) and c-axis (c). Red, blue, grey and white represent oxygen, nitrogen, carbon and hydrogen, while the blue dashed-lines indicate hydrogen bonds. Green squares express 2-fold screw axes that are shown in Figures 7-10. Figure 2 The absolute structure of the D-Alanine crystal. Views of the planes perpendicular to the a-axis (a), b-axis (b) and c-axis (c). Red, blue, grey and white represent oxygen, nitrogen, carbon and hydrogen, while the blue dashed-lines indicate hydrogen bonds. Green squares express 2-fold screw axes that are shown in Figures 7-10. Figure 3 Wavelength dependence of (a) Δn(100), (b) Δm(100) and (c) k(100) in the <100> direction of D- and L-alanine crystals. Open and closed squares are results for D- and L-alanine, respectively. Figure 4 Wavelength dependence of (a) Δn(010), (b) Δm(010) and (c) k(010) and (d) ρ(010) in the <010> direction of D- and L-alanine crystals. Open and closed circles are results for D- and L-alanine, respectively. Figure 5 Wavelength dependences of (a) Δn(001), (b) Δm(001) and (c) k(001) in the <001> direction of D- and L-alanine crystals. Open and closed triangles are results for D- and L-alanine, respectively. Figure 611 OThe chirality indexptical rotatory power per molecule in the crystalline state of D- and L-alanine crystals (ρ_c^0) and that of alanine in 6N HCl solution (ρ_s^0), and in the <010> direction of D- and L-alanine crystals.. Open and closed squares represent ρ_s^0 the chirality indices of D- and L-alanine in 6N HCl, respectively. Open and closed triangles representare ρ_s^0the chirality indices in the <010> direction of D- and L-alanine crystals, respectively. Figure 7 The handedness of the 2-fold screw axes of an L-alanine crystal along the a-axis. (a) 2-fold screw axis no. 1 (Figure 2(a)). (b) 2-fold screw axis no. 2 (Figure 2(a)). Figure 8 The handedness of the 2-fold screw axes of a D-alanine crystal along the a-axis. (a) 2-Fold screw axis no. 1 (Figure 3(a)). (b) 2-Fold screw axis no. 2 (Figure 3(a)). Figure 9 The handedness of the 2-fold screw axis of alanine crystals along the b-axis. (a) L-alanine and (b) D-alanine. Figure 10 The handedness of the 2-fold screw axis of alanine crystals along c-axis. (a) L-alanine and (b) D-alanine. Figure 11 The wavelength dependence of Δn for alanine crystals. Open and closed red squares are results for D- and L-alanine in the <100> direction, respectively. Open and closed green circles are results for D- and L-alanine in the <010> direction, respectively. Open and closed blue triangles are results for D-, L-alanine in the <001> direction, respectively. The solid line represents the calculated Δn(100) obtained from experimental values of Δn(010) and Δn(001).

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