Alkyllithium-Initiated Polymerization of Trans-1,3,5-Hexatriene and Copolymerization with Styrene

1989 ◽  
Vol 62 (2) ◽  
pp. 332-342 ◽  
Author(s):  
Roderic P. Quirk ◽  
Rajeev Bhatia
Keyword(s):  
Branched Polymers ◽  
General Effect ◽  
Block Copolymerization ◽  
Conjugated Diene ◽  
Polymer Backbone ◽  
Spectral Analyses ◽  
Effect Of Solvent ◽  
Hydrocarbon Solvents ◽  
Infrared Spectral ◽  
Conjugated Trienes

Abstract The results reported herein established the complexity of the alkyllithium-initiated anionic homopolymerization, styrene copolymerization and styrene block copolymerization of 1,3,5-hexatriene in comparison to the controlled, predictable behavior observed with dienes. As a result of 1,6- and 1,2-enchainment, conjugated diene units are formed along the polymer backbone which can react with the living carbanionic centers to produce branched polymers as indicated in Equation (1). The general effect of solvent on microstructure, as indicated by infrared spectral analyses, is analogous to that of dienes in that 1,2-addition is increased in polar versus hydrocarbon solvents. The observation of branching reactions suggests that conjugated trienes may be useful as branching agents for copolymerizations or linking reactions analogous to the behavior of divinylbenzenes.

Visible to Short-Wave Infrared Spectral Analyses of Mars from Orbit Using CRISM and OMEGA

2019 ◽  
pp. 453-483
Author(s):  
Scott L. Murchie ◽  
Jean-Pierre Bibring ◽  
Raymond E. Arvidson ◽  
Janice L. Bishop ◽  
John Carter ◽  
...  
Keyword(s):  
Short Wave ◽  
Spectral Analyses ◽  
Infrared Spectral ◽  
Short Wave Infrared

PREPARATION AND PROPERTIES OF CRYSTALLINE CANDIDIN

1956 ◽  
Vol 34 (9) ◽  
pp. 1163-1167 ◽  
Author(s):  
L. C. Vining ◽  
W. A. Taber
Keyword(s):  
Absorption Maximum ◽  
Visible Region ◽  
Crystalline Form ◽  
Molecular Formula ◽  
Amino Group ◽  
Equivalent Weight ◽  
Conjugated Diene ◽  
Antifungal Antibiotic ◽  
Infrared Spectral ◽  
Best Fit

Candidin, the antifungal antibiotic produced by Streptomycesviridoflavus, has been isolated in crystalline form. Analyses and equivalent weight values best fit a molecular formula C46H75NO17. The substance is amphoteric and probably contains one carboxyl and one amino group. Infrared spectral evidence also indicates a polyhydroxylated structure, and the absorption in the visible region shows the presence of a conjugated heptaene chromophore. An additional conjugated diene elsewhere in the molecule is suggested by hydrogenation values and the absorption maximum at 228 mμ.

Thermal Infrared Spectral Analyses of Mars from Orbit Using the Thermal Emission Spectrometer and Thermal Emission Imaging System

2019 ◽  
pp. 484-498
Author(s):  
Victoria E. Hamilton ◽  
Philip R. Christensen ◽  
Joshua L. Bandfield ◽  
A. Deanne Rogers ◽  
Christopher S. Edwards ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Imaging System ◽  
Thermal Infrared ◽  
Spectral Analyses ◽  
Infrared Spectral

Cyclic organophosphorus compounds. I. Synthesis and infrared spectral studies of cyclic hydrogen phosphites and thiophosphites

1967 ◽  
Vol 45 (21) ◽  
pp. 2501-2512 ◽  
Author(s):  
A. Zwierzak
Keyword(s):  
Hydrogen Bonding ◽  
Organophosphorus Compounds ◽  
Spectral Studies ◽  
Effect Of Solvent ◽  
Dipole Interactions ◽  
Synthetic Procedure ◽  
Infrared Spectral

A general synthetic procedure leading to cyclic hydrogen phosphites has been devised. The effect of solvent on the P==O and P—H infrared stretching modes of cyclic hydrogen phosphites and thiophosphites has been studied. It is concluded that association of cyclic hydrogen phosphites is attributable to dipole–dipole interactions rather than to hydrogen bonding.

Visible and Near-Infrared Spectral Analyses of Asteroids and Comets from Dawn and Rosetta

2019 ◽  
pp. 413-427
Author(s):  
M. Cristina De Sanctis ◽  
Fabrizio Capaccioni ◽  
Eleonora Ammannito ◽  
Gianrico Filacchione
Keyword(s):  
Near Infrared ◽  
Spectral Analyses ◽  
Infrared Spectral ◽  
Asteroids And Comets

Bulk mineralogy of the NE Syrtis and Jezero crater regions of Mars derived through thermal infrared spectral analyses

Icarus ◽  
2018 ◽  
Vol 301 ◽  
pp. 76-96 ◽  
Author(s):  
M.R. Salvatore ◽  
T.A. Goudge ◽  
M.S. Bramble ◽  
C.S. Edwards ◽  
J.L. Bandfield ◽  
...  
Keyword(s):  
Thermal Infrared ◽  
Spectral Analyses ◽  
Infrared Spectral

Investigation of thermal and fluorescent properties of benzoxazole-linked triphenylamine-based co-polyimides

2019 ◽  
Vol 32 (3) ◽  
pp. 231-241
Author(s):  
Asma Iqbal ◽  
Humaira Masood Siddiqi ◽  
Maria Zubair ◽  
Toheed Akhter ◽  
O Ok Park ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Energy Levels ◽  
Green Emission ◽  
Gel Permeation Chromatography ◽  
Orbital Energy ◽  
Fluorescent Properties ◽  
Polymer Backbone ◽  
Good Thermal Stability ◽  
Infrared Spectral ◽  
Optical Bandgaps

A series of novel fluorescent co-polyimides are obtained by combining N 1-(4-aminophenyl)- N 1-(4-(benzo[ d]oxazol-2-yl) phenyl) benzene-1,4-diamine and 4,4′-oxydianiline with four aromatic anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydiphthalic anhydride, and 4,4 ′-(hexafluoroisopropylidene)diphthalic anhydride following conventional polycondensation method. The resultant co-polyimides are characterized by elemental, Fourier transform infrared spectral analysis and gel permeation chromatography. All newly prepared polyimides (PIs) exhibit shallow highest occupied molecular orbital energy levels in the range of −4.47 to −4.98 eV and have reasonable optical bandgaps. The photoluminescence spectral analysis shows blue to green emission in solution form. Thermal and solubility properties reveal that the PIs with pendant 4-(benzo[ d]oxazol-2-yl group linked to triphenylamine unit in polymer backbone impart not only good thermal stability but also appreciable solubility making these new co-polyimides versatile for multipurpose usage.

Thermal and infrared spectral analyses of sabugalite

1988 ◽  
Vol 33 (2) ◽  
pp. 395-399 ◽  
Author(s):  
J. Čejka ◽  
Z. Urbanec ◽  
J. Čejka ◽  
J. Ederová ◽  
A. Muck
Keyword(s):  
Spectral Analyses ◽  
Infrared Spectral
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