Molecular structure and photochromic properties of 1,3-dimethylindoline-3,3′-alkano-2-spiro-2′-(6′-nitro)benzopyrans

2002 ◽  
Vol 52 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Yasuo Abe ◽  
Hiromi Ebara ◽  
Satoshi Okada ◽  
Ryuichi Akaki ◽  
Toyokazu Horii ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Photochromic Properties

The crystal and molecular structure of 3-N-pyridylsydnone

1985 ◽  
Vol 50 (8) ◽  
pp. 1764-1773 ◽  
Author(s):  
Jindřich Hašek ◽  
Paul T. Beurskens ◽  
Jiří Obrda ◽  
Stanislav Nešpůrek ◽  
Hendrik Schenk ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Pyridyl Ring ◽  
Independent Molecule ◽  
Photochromic Properties ◽  
Monoclinic System ◽  
Calculated Density ◽  
Space Group ◽  
Independent Molecules

The title compound studied for its photochromic properties crystallizes in the monoclinic system, the space group P2/c, a = 734.3(6), b = 933.3(8), c = 2 334(2) pm, β = 117.71(5)°, V = 1.416(2) nm3, Z = 8, measured and calculated density Dm = 1.51, Dx = 1.53 Mg m-3, λ(CuKα) = 154.178 pm, μ = 1.0 mm-1, F(000) = 672, Mr= 163.14, T = 296 K. Final R = 0.084 for 1 511 significant (I > 1.96σI) reflections. The molecules are roughly parallel with the (100) plane and are stacked so that the sydnone ring of the first independent molecule partly overlaps the pyridyl ring of the second independent molecule. This results in the infinite column of partly overlaping pyridyl and sydnone rings in distances 344(4) and 335(4) pm, parallel with the a axis. Symmetrically independent molecules simulate pseudo 21 axis.

Naphthopyran Dyes

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Andrew Towns
Keyword(s):  
Molecular Structure ◽  
Photochromic Properties ◽  
Important Type ◽  
Photochromic Dye ◽  
History Of ◽  
Commercially Important

AbstractThis article covers the most commercially important type of photochromic dye. It outlines which of its subclasses are of most use and how they are manufactured. The history of the industrial exploitation of this kind of colorant is briefly given before illustrating its versatility with examples of the most useful ways in which photochromic properties can be manipulated by making adjustments to molecular structure.

Molecular Structure of the Outermost Cell Wall Component of Spirillum Serpens

1977 ◽  
Vol 35 ◽  
pp. 342-343
Author(s):  
Wah Chiu ◽  
David Grano
Keyword(s):  
Molecular Structure ◽  
Cell Wall ◽  
Outer Membrane ◽  
Gel Electrophoresis ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Cell Wall Component ◽  
Protein Components ◽  
Exposure Technique ◽  
Structural Aspects

The periodic structure external to the outer membrane of Spirillum serpens VHA has been isolated by similar procedures to those used by Buckmire and Murray (1). From SDS gel electrophoresis, we have found that the isolated fragments contain several protein components, and that the crystalline structure is composed of a glycoprotein component with a molecular weight of ∽ 140,000 daltons (2). Under an electron microscopic examination, we have visualized the hexagonally-packed glycoprotein subunits, as well as the bilayer profile of the outer membrane. In this paper, we will discuss some structural aspects of the crystalline glycoproteins, based on computer-reconstructed images of the external cell wall fragments.The specimens were prepared for electron microscopy in two ways: negatively stained with 1% PTA, and maintained in a frozen-hydrated state (3). The micrographs were taken with a JEM-100B electron microscope with a field emission gun. The minimum exposure technique was essential for imaging the frozen- hydrated specimens.

On the relation between isotope effects on vapour pressure and molecular structure

1963 ◽  
Vol 60 ◽  
pp. 52-55
Author(s):  
István Kiss ◽  
Lajos Matus ◽  
István Opauszky
Keyword(s):  
Molecular Structure ◽  
Vapour Pressure ◽  
Isotope Effects

Structure elucidation by NMR spectroscopy: Assisted analysis from spectra to molecular structure

Planta Medica ◽  
2014 ◽  
Vol 80 (10) ◽  
Author(s):  
S Groscurth ◽  
T Kühn ◽  
P Kessler ◽  
V Rukachaisirikul
Keyword(s):  
Molecular Structure ◽  
Nmr Spectroscopy ◽  
Structure Elucidation ◽  
Assisted Analysis

Activity of Plasmin and Streptokinase-Activator on Substituted Arginine and Lysine Esters

1966 ◽  
Vol 16 (01/02) ◽  
pp. 018-031 ◽  
Author(s):  
S Sherry ◽  
Norma Alkjaersig ◽  
A. P Fletcher
Keyword(s):  
Molecular Structure ◽  
Methyl Ester ◽  
Comparative Studies ◽  
Esterase Activity ◽  
Methyl Esters ◽  
Hydrolytic Activity ◽  
The Other ◽  
Other Hand

SummaryComparative studies have been made of the esterase activity of plasmin and the streptokinase-activator of plasminogen on a variety of substituted arginine and lysine esters. Human plasmin preparations derived by different methods of activation (spontaneous in glycerol, trypsin, streptokinase (SK) and urokinase) are similar in their esterase activity; this suggests that the molecular structure required for such esterase activity is similar for all of these human plasmins. Bovine plasmin, on the other hand, differs from human plasmin in its activity on several of the substrates studied (e.g., the methyl esters of benzoyl arginine and tosyl, acetyl and carbobenzoxy lysine), a finding which supports the view that molecular differences exist between the two animal plasmins. The streptokinase-activator hydrolyzes both arginine and lysine esters but the ratios of hydrolytic activity are distinct from those of plasmin and of other activators of plasminogen. The use of benzoyl arginine methyl ester as a substrate for the measurement of the esterase activity of the streptokinase-activator is described.

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