Effect of amino group protonation on the carboxyl group in aqueous glycine observed by O 1s X-ray emission spectroscopy

The valence electronic structures of the amino acid glycine in aqueous solution were investigated in detail through X-ray emission spectroscopy at O 1s excitation under selective excitation conditions of the CO site in the carboxyl group.

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Transformation of the Carboxyl Group of an Amino Acid to Variously Substituted Imidazoles through a Davidson-Type Heterocyclization

Synthesis ◽

10.1055/s-0037-1612084 ◽

2019 ◽

Vol 51 (09) ◽

pp. 1961-1968 ◽

Cited By ~ 1

Author(s):

Jim Küppers ◽

Michaela Hympánová ◽

Tim Keuler ◽

Andreas Schneider ◽

Gregor Schnakenburg ◽

...

Keyword(s):

Crystal Structure ◽

Amino Acids ◽

Amino Acid ◽

Carboxylic Acid ◽

Building Blocks ◽

Carboxyl Group ◽

Amino Group ◽

Combinatorial Approach ◽

X Ray ◽

Imidazole Derivatives

The modification of amino acids leads to valuable building blocks for the synthesis of bioactive compounds. By keeping the amino group protected, the carboxylic acid functionality can be converted in two steps into an imidazole moiety via a Davidson-like heterocyclization. This reaction allows for a combinatorial approach, in which two positions at the heterocycle can be modified. Herein, we report the synthesis of such imidazole derivatives by employing N-protected cyclohexylalanine as the starting material. Different α-halo ketones were used and two points of diversity, positions 4 and 5, were examined. The structure of the final imidazole derivatives was confirmed by three X-ray crystal structure analyses and their protease inhibiting activities were evaluated.

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Structural Study of a new Compound Based on Acid 1,4-Cyclohexanedicarboxylic (1,4-CDC)

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v6i1.969 ◽

2010 ◽

Vol 6 (1) ◽

pp. 891-896

Author(s):

Manel Halouani ◽

M. Dammak ◽

N. Audebrand ◽

L. Ktari

Keyword(s):

Aqueous Solution ◽

Water Molecules ◽

Carboxyl Group ◽

X Ray Diffraction ◽

Compound I ◽

Unit Cell Parameters ◽

Monoclinic System ◽

X Ray ◽

Cell Parameters ◽

Cyclohexanedicarboxylic Acid

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.

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Chemical and electronic structures of liquid methanol from x-ray emission spectroscopy and density functional theory

Physical Review B ◽

10.1103/physrevb.71.104205 ◽

2005 ◽

Vol 71 (10) ◽

Cited By ~ 67

Author(s):

Stepan Kashtanov ◽

Andreas Augustson ◽

Jan-Erik Rubensson ◽

Joseph Nordgren ◽

Hans Ågren ◽

...

Keyword(s):

Density Functional Theory ◽

Electronic Structures ◽

Emission Spectroscopy ◽

Density Functional ◽

Functional Theory ◽

X Ray

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Formation of Interatomic Bonds of the Fumed Synthesis of Composites SiO2+Al2O3

Фізика і хімія твердого тіла ◽

10.15330/pcss.16.2.425-431 ◽

2015 ◽

Vol 16 (2) ◽

pp. 425-431

Author(s):

Ya.V. Zaulychnyy ◽

М.V. Karpetz ◽

Y.V. Yavorskyi ◽

V.М. Gun'ko ◽

V.I. Zarko ◽

...

Keyword(s):

Aluminum Oxide ◽

Silicon Dioxide ◽

Electronic Structures ◽

Emission Spectroscopy ◽

Mass Ratio ◽

X Ray Diffraction ◽

X Ray ◽

Valence Electrons

Crystalline and electronic structures of SiO2/Al2O3 mixtures have been analyzed using X-ray diffraction (XRD) and ultra-soft X-ray emission spectroscopy (USXES). Comparison of ultrasoft X-ray emission AlLα-, SiLα- and OKα-bands redistribution Alsp-, Sisp- and Op-valence electrons when changing the mass ratio (0,23Al2O3+0,77 SiO2;, 0,30Al2O3+0,70SiO2; 0,75Al2O3+25 SiO2) and depending on the method of obtaining them. Expansion OKα-emission bands showed an increase in population of Opπ-levels of oxygen in the formation of pyrogenic composites with different contents of aluminum oxide and silicon dioxide. Analysis AlLα-, SiLα- emission bands allowed to explain the increase of population Opπ-levels of oxygen and present the morphology formation of particles different of pyrogenic composites during synthesis.

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POLARIZATION DEPENDENCE OF RESONANT SOFT X-RAY EMISSION SPECTRA IN Ce COMPOUNDS

Surface Review and Letters ◽

10.1142/s0218625x02003184 ◽

2002 ◽

Vol 09 (02) ◽

pp. 983-987 ◽

Cited By ~ 8

Author(s):

M. WATANABE ◽

Y. HARADA ◽

M. NAKAZAWA ◽

Y. ISHIWATA ◽

R. EGUCHI ◽

...

Keyword(s):

Energy Range ◽

Electronic Structures ◽

Emission Spectroscopy ◽

Electronic States ◽

Emission Spectra ◽

Polarization Dependence ◽

Raman Peak ◽

Electron Hole ◽

Resonant Energy ◽

X Ray

The electronic structures of Ce compounds have been investigated by means of resonant soft X-ray emission spectroscopy (RXES) excited at resonant energy range of Ce 3d → 4f absorption. Polarization dependence of the RXES shows information on concerning electronic states. In CeO 2, the Ce 4f → 3d RXES spectra are interpreted as electronic structures hybridized between 4f0 and [Formula: see text] states. Peaks appearing in the spectra are attributed to bonding, nonbonding, and antibonding states between those states, while the spectra of CeRh 3 cannot be explained by only using the hybridization between 4f0 and [Formula: see text] states. The spectra have large broad Raman peak, especially when the excitation photon energy is set at satellite of Ce 3d → 4f absorption. We attribute the origin of the broad Raman peak to hybridization states involving electron–hole pairs.

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Hydrothermal Synthesis of SrSO4:Eu2+ Microcrystals with Different Morphologies and its Luminescence Properties

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.633-634.341 ◽

2014 ◽

Vol 633-634 ◽

pp. 341-344 ◽

Cited By ~ 1

Author(s):

Jia Yue Sun ◽

Qiu Mei Di ◽

Liu Han ◽

Qi Guang Xu ◽

Chen Liang Ma

Keyword(s):

Electron Microscopy ◽

Aqueous Solution ◽

Scanning Electron Microscopy ◽

Optical Properties ◽

Hydrothermal Synthesis ◽

Emission Spectroscopy ◽

Electron Trapping ◽

X Ray Diffraction ◽

X Ray ◽

Scanning Electron

Electron trapping materials SrSO4:Eu2+were prepared by hydrothermal method from fatty alcohol polyoxyethylene (3) ether (AEO-3) aqueous solution at 200 °C for 20 h. The phase structure, microstructure and optical properties were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and excitation-emission spectroscopy (PL-PLE), respectively.

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Specificity of the transport system for neutral amino acids in the hamster intestine

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1962.202.5.919 ◽

1962 ◽

Vol 202 (5) ◽

pp. 919-925 ◽

Cited By ~ 87

Author(s):

Edmund C. C. Lin ◽

Hiroshi Hagihira ◽

T. Hastings Wilson

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Transport System ◽

Side Chain ◽

Carboxyl Group ◽

Amino Group ◽

Methyl Group ◽

Neutral Amino Acids ◽

Active Transport System ◽

Everted Sacs

The specificity of the active transport system for neutral amino acids has been studied with everted sacs of hamster intestine. Amino acids with modifications or replacements of the carboxyl, amino, or α-hydrogen groups were poorly transported and were poor inhibitors of the transport of other l-amino acids. The carboxyl group must remain free, the amino group must not be in the tertiary or quaternary state, and the α-hydrogen can not be replaced by a methyl group without serious effect on the transport rate. It was concluded that the l-amino acids were distinguished from the d-isomers by the interaction of the carrier with the carboxyl group, the amino group, and the α-hydrogen. The side chain of the amino acid must be nonpolar but there is relatively little restriction on its structure.

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Search of amino group in the Universe: 2-aminopyridine

Serbian Astronomical Journal ◽

10.2298/saj1591081s ◽

2015 ◽

pp. 81-86

Author(s):

M.K. Sharma ◽

M. Sharma ◽

A.K. Sharma ◽

S. Chandra

Keyword(s):

Amino Acid ◽

Interstellar Medium ◽

Galactic Center ◽

Close Association ◽

Spectroscopic Studies ◽

Interstellar Space ◽

Amino Group ◽

The Earth ◽

The Universe ◽

Amino Acid Glycine

In search for life in the Universe, scientists are interested in identification of molecules having amino (-NH2) group in the interstellar space. The aminoacetonitrile (NH2CH2CN), which is precursor of the simplest amino acid glycine (NH2CH2COOH), is identified near the galactic center. The 2-Aminopyridine (H2NC5H4N) is of interest for scientists as it has a close association with life on the earth. Based on spectroscopic studies, we have calculated intensities of 2-Aminopyridine lines due to transitions between the rotational levels up to 47 cm?1 and have found a number of lines which may help in its identification in the interstellar medium. Frequencies of some of these transitions are found close to those detected in the envelope of IRC +10216 that are not assigned to any of the known species.

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