Experiment: Characterization of samples The characterization of d-and L-alanine crystals was performed by the element analysis(C, H and N) and X-ray structure analysis. It indicates that D-alanine and L alanine are pure single crystals containing no crystalline water
Experiment: Experiment:Characterization of samples Characterization of samples The characterization of D The characterization of D - and L -alanine alanine crystals was performed by crystals was performed by the element the element analysis analysis (C, H and N) and (C, H and N) and X -ray structure ray structure analysis analysis. It indicates that D . It indicates that D -alanine alanine and L - alanine alanine are pure single crystals pure single crystals containing containing no crystalline water no crystalline water
Experiment: Characterization of samples The crystal structures are orthorhombic with the same space group P212121>Z=4, with lattice constants a =0.60388(1),0.60344(5) nm,b=123670(3)2123668(8)nm,2C= 0.580002,0.57879(3) nm ofd-andL alanine(300K),a=β=y=90°
Experiment: Experiment:Characterization of samples Characterization of samples The crystal structures are orthorhombic with The crystal structures are orthorhombic with the same space group the same space group P2 1 2 1 2 1, Z=4, with , Z=4, with lattice constants a = 0.60388(1), 0.60344(5) lattice constants a = 0.60388(1), 0.60344(5) nm, b = 1.23670(3), 1.23668(8) nm , c = nm, b = 1.23670(3), 1.23668(8) nm , c = 0.58000(2), 0.57879(3) nm of D 0.58000(2), 0.57879(3) nm of D -and L - alanine alanine (300K), (300K), α = β= γ = 90 °
Experiment: Characterization of samples The rotation angle S of the D-and L-alanine solution was measured on polarimeter pe 241MC with the wavelength of 589.6 nm at 293K. By using the formula of [a=5/(L+c), the corresponding a values of D-and L alanine were shown to be the same absolute value and of opposite signs
Experiment: Experiment:Characterization of samples Characterization of samples The rotation angle The rotation angle ζ of the D of the D - and L - alanine alanine solution was measured on solution was measured on Polarimeter Polarimeter PE - 241MC with the wavelength of 589.6 nm at with the wavelength of 589.6 nm at 293K. By using the formula of [ 293K. By using the formula of [ α] = ζ / (L+C), / (L+C), the corresponding the corresponding α values of D values of D - and L - alanine alanine were shown to be the same absolute were shown to be the same absolute value and of opposite signs. value and of opposite signs
Experiment: Apparatus Schematic diagram of the apparatus Alanine Photodetector cry talt Wollaston He-Ne laser Temperature prsm Controlling Photodetector Vacuum system
Experiment: Experiment: Apparatus Apparatus Schematic diagram of the apparatus Schematic diagram of the apparatus
Experiment: Measurement Linearly polarized light of wavelength 632. 8 nm from He-Ne laser source passes through a transparent chiral material of length d that is located in vacuum temperature-control system The direct measurement of the polarization direction of a light beam e.g. the rotation signal must be converted into an amplitude signal with the aid of a polarization-optical analyzer Wollaston prism is a beam splitter that splits the linearly polarized light beam into two component beams polarized normal to each other
Experiment: Measurement Experiment: Measurement Linearly polarized light of wavelength 632.8 nm Linearly polarized light of wavelength 632.8 nm from He from He -Ne laser source passes through a laser source passes through a transparent transparent chiral material of length material of length d that is that is located in vacuum temperature located in vacuum temperature -control system. control system. The direct measurement of the polarization The direct measurement of the polarization direction of a light beam e.g. the rotation signal direction of a light beam e.g. the rotation signal must be converted into an amplitude signal with must be converted into an amplitude signal with the aid of a polarization the aid of a polarization -optical analyzer. optical analyzer. Wollaston prism is a beam splitter that splits the Wollaston prism is a beam splitter that splits the linearly polarized light beam into two component linearly polarized light beam into two component beams polarized normal to each other. beams polarized normal to each other