Zinc and iron complexes of a helix-directing (1R,2R)-cyclohexyl salen ligand with phenanthryl sidearms

2009 ◽  
Vol 87 (1) ◽  
pp. 224-231 ◽  
Author(s):  
Alexander V Wiznycia ◽  
John Desper ◽  
Christopher J Levy
Keyword(s):  
Metal Complexes ◽  
Iron Complexes ◽  
Single Species ◽  
Nmr Data ◽  
Salen Complexes ◽  
Dft Simulations ◽  
Helical Molecules ◽  
Salen Ligand ◽  
C Nmr

A symmetrical salen ligand is formed by the condensation of (1R,2R)-diaminocyclohexane with 4-hydroxy-3-phenanthrenecarboxaldehyde. Crystallographic characterization of the metal complexes (ZnII, FeII, and FeIII) show 1:1 mixtures of diastereomeric M and P helical molecules. ECD spectra of the ZnII complex combined with DFT simulations strongly suggest that the M conformation is dominant in solution. This is supported by 1H and 13C NMR data, which are consistent with a single species in solution.Key words: zinc, iron, ECD, DFT, salen complexes.

scholarly journals Characterization of Cerebral Glutamine Uptake from Blood in the Mouse Brain: Implications for Metabolic Modeling of 13C NMR Data

2014 ◽  
Vol 34 (10) ◽  
pp. 1666-1672 ◽  
Author(s):  
Puneet Bagga ◽  
Kevin L Behar ◽  
Graeme F Mason ◽  
Henk M De Feyter ◽  
Douglas L Rothman ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Metabolic Model ◽  
Synthesis Rate ◽  
Nmr Studies ◽  
Nmr Data ◽  
Glutamine Synthesis ◽  
Time Courses ◽  
Glutamine Uptake ◽  
C Nmr

13C Nuclear Magnetic Resonance (NMR) studies of rodent and human brain using [1-13C]/[1,6-13C2]glucose as labeled substrate have consistently found a lower enrichment (~25% to 30%) of glutamine-C4 compared with glutamate-C4 at isotopic steady state. The source of this isotope dilution has not been established experimentally but may potentially arise either from blood/brain exchange of glutamine or from metabolism of unlabeled substrates in astrocytes, where glutamine synthesis occurs. In this study, the contribution of the former was evaluated ex vivo using 1H-[13C]-NMR spectroscopy together with intravenous infusion of [U-13C5]glutamine for 3, 15, 30, and 60 minutes in mice. 13C labeling of brain glutamine was found to be saturated at plasma glutamine levels > 1.0 mmol/L. Fitting a blood–astrocyte–neuron metabolic model to the 13C enrichment time courses of glutamate and glutamine yielded the value of glutamine influx, VGln(in), 0.036 ± 0.002 μmol/g per minute for plasma glutamine of 1.8 mmol/L. For physiologic plasma glutamine level (~0.6 mmol/L), VGln(in) would be ~0.010 μmol/g per minute, which corresponds to ~6% of the glutamine synthesis rate and rises to ~11% for saturating blood glutamine concentrations. Thus, glutamine influx from blood contributes at most ~20% to the dilution of astroglial glutamine-C4 consistently seen in metabolic studies using [1-13C]glucose.

Far-red absorbing azodipyrrin dyes — Synthesis, X-ray crystallographic, and spectral characterization of 1,9-diazodipyrrins and their metal complexes

2011 ◽  
Vol 89 (4) ◽  
pp. 481-487 ◽  
Author(s):  
Yan Li ◽  
David Dolphin
Keyword(s):  
Metal Complexes ◽  
Zinc Complex ◽  
Nickel Complexes ◽  
Crystallographic Analysis ◽  
Zinc Complexes ◽  
Spectral Characterization ◽  
X Ray ◽  
Almost All ◽  
C Nmr

A series of novel 1,9-diazodipyrrins (4) were readily synthesized by reacting aryldiazonium salts with 5-aryldipyrromethanes under both acidic and basic conditions. The zinc complex of 1,9-diphenylazodipyrrin (5aZn) was confirmed by X-ray crystallographic analysis, and 1,9-diazodipyrrins and their zinc and nickel complexes (5M) were characterized by 1H and 13C NMR, IR, UV–vis, and MS. All of the metal complexes absorb almost all colours of the rainbow; the absorption maximums are >650 nm and the half-band widths are over 100 nm. The fluorescence of the zinc complexes of 1,9-diphenylazodipyrrin (5aZn) and 1,9-di(2-iodophenylazo)dipyrrin (5cZn) were also explored.

Darstellung und Strukturelle Charakterisierung von cis-und trans- Dicyclohexyl-3,3′,4,4′-tetracarbonsäure-tetramethylestern / Preparation and Structural Characterization of cis- and trans-Tetramethyl Dicyclohexyl-3,3′,4,4′-tetracarboxylates

2001 ◽  
Vol 56 (2) ◽  
pp. 189-201
Author(s):  
Akinori Shiotani
Keyword(s):  
Catalytic Hydrogenation ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Trans Isomers ◽  
X Ray ◽  
Nmr Data ◽  
Methoxycarbonyl Group ◽  
Cis And Trans ◽  
C Nmr

Abstract In the catalytic hydrogenation of tetramethyl biphenyl-3,3′,4,4′-tetracarboxylate, tetramethyl dicyclohexyl-3,3′,4,4′-tetracarboxylates were obtained, from which we have isolated cis isomers as crystals. The base-catalyzed isomerization afforded the trans isomers. The structure of the products isolated was determined by single-crystal x-ray diffraction, which clearly reveals the axial and equatorial positions of the methoxycarbonyl group. The structures in solution are supported by 1H and 13C NMR data, and also by two-dimensional COSY techniques.

Glucan isolated from leaves of Althaea officinalis L.

1983 ◽  
Vol 48 (7) ◽  
pp. 2082-2087 ◽  
Author(s):  
Alžbeta Kardošová ◽  
Jozef Rosík ◽  
Rudolf Toman ◽  
Peter Capek
Keyword(s):  
Medicinal Plant ◽  
Periodate Oxidation ◽  
Linear Structure ◽  
Water Soluble ◽  
Partial Hydrolysis ◽  
Methylation Analysis ◽  
Glycosidic Bonds ◽  
Nmr Data ◽  
Althaea Officinalis ◽  
C Nmr

A water-soluble low-molecular D-glucan was isolated from leaves of the medicinal plant marsh-mallow (Althaea officinalis L.). The results of methylation analysis, partial hydrolysis, periodate oxidation, and 13C NMR data indicated a virtually linear structure with α-(1→6) glycosidic bonds.

Synthesis and characteristics of ethylenediamine-N,N'-di-S-α-isovalerate and isomers of its cobalt(III) complexes

1982 ◽  
Vol 47 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Milan Strašák ◽  
František Bachratý ◽  
Jaroslav Majer
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Chemical Parameters ◽  
Methyl Group ◽  
Nmr Data ◽  
Physico Chemical ◽  
Natural Amino Acids ◽  
C Nmr

The synthesis and physico-chemical parameters are described of a new complexone based on natural amino acids, viz. ethylenediamine-N,N'-di-S-α-isovalerate (SS-EDDIV). 1H- and 13C-NMR data revealed that the methyl group in the substance are not equivalent. The isomers of the cobalt(III) complex with the asymmetric tetradentate SS-EDDIV ligand were prepared and separated; their characteristics are given. The absolute configuration of two of the five theoretically feasible isomers was determined based on their electronic absorption spectra and circular dichroism data.

Synthesis and characterization of polyimides containing a chiral dimine link that mimics the salen ligand

2004 ◽  
Vol 7 (4) ◽  
pp. 377-390 ◽  
Author(s):  
Turgay Seçkin ◽  
Süleyman Köytepe ◽  
Murat Yigˇit ◽  
Engin Çetinkaya
Keyword(s):  
Synthesis And Characterization ◽  
Salen Ligand

scholarly journals Structural Investigations of C-Nitrosobenzenes. Part 3.1 Solid-state and Solution 13C NMR Studies, and Crystal Structure of E-(4-CIC6H4NO)2

1999 ◽  
Vol 23 (3) ◽  
pp. 202-203
Author(s):  
Daniel A. Fletcher ◽  
Brian G. Gowenlock ◽  
Keith G. Orrell ◽  
David C. Apperley ◽  
Michael B. Hursthouse ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
13C Nmr ◽  
Nmr Studies ◽  
Structural Investigations ◽  
Nmr Data ◽  
C Nmr

Solid-state and solution 13C NMR data for the monomers and dimers of 3- and 4-substituted nitrosobenzenes, and the crystal structure of E-(4-CIC6H4NO)2 are reported.

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