On the syntheses and the optical properties of optically active 2-pyrazoline compounds

1979 ◽  
Vol 57 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Makoto Mukai ◽  
Takashi Miura ◽  
Masahiro Nanbu ◽  
Toshinobu Yoneda ◽  
Yohji Shindo
Keyword(s):  
Optical Properties ◽  
Optical Activity ◽  
Optically Active ◽  
Spectroscopic Techniques ◽  
Considerable Influence ◽  
Pyrazoline Ring

Optically active 2-pyrazolines were synthesized and their optical properties were studied using various spectroscopic techniques to investigate the effects of substituents at the 3 and 5 positions of the 2-pyrazoline ring on their optical activity. It was found that in the case of 5-substituted-1,3-diphenyl-2-pyrazoline derivatives, the substituent at the 5 position has considerable influence on the optical activity, whereas in 3-substituted-1,5-diphenyl-2-pyrazoline derivatives, the substituent at the 3 position has no such influence.

Chiral π-conjugated organoboron polymers

2009 ◽  
Vol 81 (3) ◽  
pp. 433-437 ◽  
Author(s):  
Fukashi Matsumoto ◽  
Yoshiki Chujo
Keyword(s):  
Optical Properties ◽  
Reference Material ◽  
Concentration Dependence ◽  
Optical Activity ◽  
Solvent Effects ◽  
Fluorescence Emission ◽  
Cd Spectroscopy ◽  
Optically Active ◽  
Side Chain ◽  
Influence Of Solvent

A novel π-conjugated organoboron polymer with a chiral side chain was prepared by way of hydroboration polymerization between an optically active diyne monomer and triisopropylphenylborane. The achiral analog of this organoboron polymer was also prepared as reference material. Optical properties and optical activity were investigated by UV-vis absorption, fluorescence emission, and circular dichroism (CD) spectroscopy. Concentration dependence and the influence of solvent effects upon chiroptical activity are described.

Differential polarization imaging of sickled cells

1988 ◽  
Vol 46 ◽  
pp. 62-63
Author(s):  
Marcos F. Maestre
Keyword(s):  
Optical Properties ◽  
Theoretical Approach ◽  
Polarized Light ◽  
Polarization Microscopy ◽  
Spectroscopic Techniques ◽  
Polarization Imaging ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Microscopic Scale ◽  
Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

scholarly journals Orientation dependence of optical activity in light scattering by nanoparticle clusters

2022 ◽  
Author(s):  
Atefeh Fazel Najafabadi ◽  
Baptiste Auguié
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Optical Activity ◽  
Incident Light ◽  
Spatial Arrangement ◽  
Orientation Dependence ◽  
Nanoparticle Clusters

The optical properties of nanoparticle clusters vary with the spatial arrangement of the constituent particles, but also the overall orientation of the cluster with respect to the incident light. This...

scholarly journals Enhanced gyrotropic birefringence and natural optical activity on electromagnon resonance in a helimagnet

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
S. Iguchi ◽  
R. Masuda ◽  
S. Seki ◽  
Y. Tokura ◽  
Y. Takahashi
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Optical Activity ◽  
Optical Rotation ◽  
Magnetoelectric Coupling ◽  
Optically Active ◽  
Crystalline Solid ◽  
Spin Order ◽  
Active Devices ◽  
Principal Axes

AbstractSpontaneous symmetry breaking in crystalline solid often produces exotic nonreciprocal phenomena. As one such example, the unconventional optical rotation with nonreciprocity, which is termed gyrotropic birefringence, is expected to emerge from the magnetoelectric coupling. However, the fundamental nature of gyrotropic birefringence remains to be examined. Here w`e demonstrate the gyrotropic birefringence enhanced by the dynamical magnetoelectric coupling on the electrically active magnon resonance, i.e. electromagnon, in a multiferroic helimagnet. The helical spin order having both polarity and chirality is found to cause the giant gyrotropic birefringence in addition to the conventional gyrotropy, i.e. natural optical activity. It is demonstrated that the optical rotation of gyrotropic birefringence can be viewed as the nonreciprocal rotation of the optical principal axes, while the crystallographic and magnetic anisotropies are intact. The independent control of the nonreciprocal linear (gyrotropic birefringence) and circular (natural optical activity) birefringence/dichroism paves a way for the optically active devices.

Optical activity and enantiomorphism

2004 ◽  
Author(s):  
Robert E. Newnham
Keyword(s):  
Optical Activity ◽  
Polarized Light ◽  
Polarization Vector ◽  
Optically Active ◽  
Crystal Thickness ◽  
Helical Structures ◽  
Active Materials ◽  
Circularly Polarized ◽  
Space Groups ◽  
Polarized Waves

When plane-polarized light enters a crystal it divides into right- and lefthanded circularly polarized waves. If the crystal possesses handedness, the two waves travel with different speeds, and are soon out of phase. On leaving the crystal, the circularly polarized waves recombine to form a plane polarized wave, but with the plane of polarization rotated through an angle αt. The crystal thickness t is in mm, and α is the optical activity coefficient expressed in degrees/mm. The polarization vector of the combined wave can be visualized as a helix, turning α ◦/mm path length in the optically-active medium. Because of the low symmetry of a helix, optical activity is not observed in many high symmetry crystals. Point groups possessing a center of symmetry are inactive. In relating α to crystal chemistry it is convenient to divide optically-active materials into two categories: Those which retain optical activity in liquid form, and those which do not. It has long been known that optically-active solutions crystallize to give optically-active solids. This follows from the fact that molecules lacking mirror or inversion symmetry can never crystallize in a pattern containing such symmetry elements. Thus one way of obtaining optically-active materials is to begin with optically-active molecules, as in Rochelle salt, tartaric acid and cane sugar. Few of these crystals are very stable, however, and the optical activity coefficients are usually small, typically 2◦/mm. The same is true of many inorganic solids, though they are seldom optically active in the liquid state. For NaClO3 and MgSO4·7H2O, α is about 3◦/mm. Quartz and selenium, however, have coefficients an order of magnitude larger, showing the importance of helical structures to optical activity. Both compounds crystallize as right- and left-handed forms in space groups P312 and P322, with helices spiraling around the trigonal screw axes. Quartz contains nearly regular SiO4 tetrahedra with Si–O distances of 1.61 Å. Levorotatory quartz belongs to space group P312 and contains right-handed helices; enantiomorphic dextrorotatory quartz crystallizes in P322. Trigonal selenium also contains helical chains.

scholarly journals BODIPY Derivatives: Synthesis and Evaluation of Their Optical Properties

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 10
Author(s):  
Raquel C. R. Gonçalves ◽  
Mariana B. Nogueira ◽  
Susana P. G. Costa ◽  
M. Manuela M. Raposo
Keyword(s):  
Optical Properties ◽  
Water Solution ◽  
Spectroscopic Techniques ◽  
Absorption Bands ◽  
Photophysical Study ◽  
Anions And Cations ◽  
Preliminary Study ◽  
Nm Range

Three 3-difluoroborodipyrromethene (BODIPY) derivatives functionalized at the meso and 2 positions were synthesized with 22–59% yield. The compounds were characterized by the usual spectroscopic techniques and a photophysical study was also undertaken. The BODIPY derivatives presented absorption bands in the 494–512 nm range and were also emissive with fluorescence bands in the 512–514 nm interval. A preliminary study on the sensing ability of a BODIPY derivative functionalized at position 2 with a benzimidazole was carried out in acetonitrile and acetonitrile/water (75:25) solutions in the presence of anions and cations, with environmental, biomedical, and analytical relevance. A highly selective response was obtained for Hg2+ and Fe3+ in acetonitrile/water solution.

scholarly journals Twins in YAl3(BO3)4 and K2Al2B2O7 Crystals as Revealed by Changes in Optical Activity

Crystals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Johannes Buchen ◽  
Volker Wesemann ◽  
Steffen Dehmelt ◽  
Andreas Gross ◽  
Daniel Rytz
Keyword(s):  
Optical Properties ◽  
Optical Activity ◽  
Nonlinear Optical ◽  
Frequency Conversion ◽  
Optical Rotation ◽  
Visible Spectrum ◽  
Rotatory Power ◽  
Nonlinear Optical Properties ◽  
Crystal Quality ◽  
Optical Rotatory Dispersion

Many borate crystals feature nonlinear optical properties that allow for efficient frequency conversion of common lasers down into the ultraviolet spectrum. Twinning may degrade crystal quality and affect nonlinear optical properties, in particular if crystals are composed of twin domains with opposing polarities. Here, we use measurements of optical activity to demonstrate the existence of inversion twins within single crystals of YAl 3 (BO 3 ) 4 (YAB) and K 2 Al 2 B 2 O 7 (KABO). We determine the optical rotatory dispersion of YAB and KABO throughout the visible spectrum using a spectrophotometer with rotatable polarizers. Space-resolved measurements of the optical rotation can be related to the twin structure and give estimates on the extent of twinning. The reported dispersion relations for the rotatory power of YAB and KABO may be used to assess crystal quality and to select twin-free specimens.

ChemInform Abstract: ON THE SYNTHESES AND THE OPTICAL PROPERTIES OF OPTICALLY ACTIVE 2-PYRAZOLINE COMPOUNDS

1979 ◽  
Vol 10 (24) ◽  
Author(s):  
M. MUKAI ◽  
T. MIURA ◽  
M. NANBU ◽  
T. YONEDA ◽  
Y. SHINDO
Keyword(s):  
Optical Properties ◽  
Optically Active
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