title: Gyration and Permittivity of Ethylenediammonium Sulfate Crystals.
abstract: Ethylenediammonium sulfate (EDS) crystals were grown from aqueous solution and cleaved into thin (100-500 micron) plates. The 422 point group of EDS was confirmed by X-ray diffraction. The constitutive relations of EDS crystals were determined through generalized ellipsometry with an instrument that uses four photoelastic modulators (4PEM). The optical rotation at 500 nm, for example, was + 22.9°/mm along the optic axis and - 12.1°/mm perpendicular to the optic axis for the P41 21 2 crystals. Enantiomorphous twins frequently form across the (001) plane. Mirrored halves must be separated by cleavage in advance of optical measurements. Chirality 28:460-465, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Chemistry and Molecular Design Institute, New York University, New York City, New York, USA.
authors.forename: Shane
authors.initials: S
authors.lastname: Nichols
authors.affiliation: Department of Chemistry and Molecular Design Institute, New York University, New York City, New York, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Martin
authors.affiliation: Department of Chemistry and Molecular Design Institute, New York University, New York City, New York, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Chemistry and Molecular Design Institute, New York University, New York City, New York, USA.
authors.forename: Bart
authors.initials: B
authors.lastname: Kahr
keywords: bianisotropic; chiral twinning; ellipsometry; gyration; multiple reflections; optical activity; polarimetry