The structure and IR spectra of oxygen-containing carbofunctional trimethylgermanes

This report is a continuation of previous research on the H2O2-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H2O2-mediated oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H2O2 resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.

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Sulphoamidic Phtalocyaninic Pigments and Dyes(II)

Revista de Chimie ◽

10.37358/rc.08.5.1820 ◽

2008 ◽

Vol 59 (5) ◽

Author(s):

Elena Stingaciu ◽

Corneliu Minca ◽

Ion Sebe

Keyword(s):

Ir Spectra ◽

Aromatic Amines ◽

Free Groups ◽

Cyanuric Chloride ◽

Layer Chromatography ◽

Phenylene Diamine

This work concerns the synthesis of pigments and phtalocyanine dyes obtained through the sulphonation of copper phtalocyanine and amidation with some aliphatic and aromatic amines (lauryl-amine, i-propyl-amine, hexadecyl-amine, stearyl-amine and acetyl-p-phenylene-diamine) with good properties for the electrotechnic utilisation and for toner materials. The pigments with amino free groups are transformed by condensation with cyanuric chloride in phtalocyanine pigments with different tinctorial properties. The dyes were analyzed through the layer chromatography and were characterized on the IR spectra bases and tinctorial tests.

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DIAMAP: NEW APPLICATIONS FOR PROCESSING IR SPECTRA OF FLUID-RICH DIAMONDS AND MAPPING DIAMONDS CONTAINING ISOLATED NITROGEN (TYPE IB) AND BORON (TYPE IIB)

10.1130/abs/2017am-298964 ◽

2017 ◽

Author(s):

Lorne Loudin ◽

◽

Daniel Howell ◽

Yakov Weiss ◽

Karen V. Smit ◽

...

Keyword(s):

Ir Spectra ◽

New Applications

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Circular dichroism and infrared study of β-turn formation in repeat peptides of elastin

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19871356 ◽

1987 ◽

Vol 52 (5) ◽

pp. 1356-1361

Author(s):

S. Abdel Rahman ◽

M. Elsafty ◽

A. Hattaba

Keyword(s):

Circular Dichroism ◽

Solid State ◽

Ir Spectra ◽

Chain Length ◽

Room Temperature ◽

Infrared Study ◽

Feature Characteristic ◽

C 50 ◽

The Stability ◽

Circular Dichroïsm

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.

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A Contribution to the Structure Characteristics and Phase Composition of Vanadium-Phosphorus Catalysts Prepared from the VOPO4.xH2O.yH3PO4 Precursor

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19922475 ◽

1992 ◽

Vol 57 (12) ◽

pp. 2475-2480 ◽

Cited By ~ 1

Author(s):

Milan Brutovský ◽

Štefan Gerej ◽

Ján Novák ◽

Lucia Ferdinandyová

Keyword(s):

Heat Treatment ◽

Phase Composition ◽

Ir Spectra ◽

Metal Cations ◽

Preparation Procedure ◽

Final Temperature ◽

Structure Characteristics ◽

Heat Treatment Regime ◽

Condensed Phosphates ◽

Defective Crystals

Catalysts were prepared from VOPO4.xH2O.yH3PO4 (x = 0.3-2, y = 0.2-0.85) by reduction with SO2 up to a final temperature of 750-800 °C, and activated in a reaction mixture of 1.0-1.4% butane in air up to 500 °C. The structure characteristics and phase composition of the catalysts were found to be affected by the preparation procedure and heat treatment regime. Their diffraction lines and IR spectra revealed that the catalysts from larger and less defective crystals than catalysts which were obtained from the VOHPO4.xH2O.yH3PO4 precursor and activated in the reaction mixture at temperatures up to 500 °C. In the catalysts prepared by the above procedure, the tendency to the formation of phases of higher-condensed phosphates, in particular VO(PO3)2 or even V(PO3)3, increases with increasing n(P):n(V) ratio and is then more pronounced than with vanadium-phosphorus catalysts prepared by other procedures. The tendency to the formation of the catalytically less active condensed phosphates is partly suppressed by the embedding of modifying metal cations (Fe or Cu in this case).

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