Darstellung und Eigenschaften von Fe[ClC(COOEt)2]3 / Synthesis and Properties of Fe[ClC(COOEt)2]3

1983 ◽  
Vol 38 (1) ◽  
pp. 30-33
Author(s):  
W. Petz ◽  
S. Kremer
Keyword(s):  
Spectroscopic Properties ◽  
High Yield ◽  
Paramagnetic Complex

Fe2(CO)9 reacts with Cl2C(COOEt)2 to give the paramagnetic complex Fe[ClC(COOEt)2]3 in high yield. The magnetic and spectroscopic properties of this complex are discussed.

scholarly journals Darstellung und Charakterisierung einfacher α-Sila- und α,ω-Disilaalkane als Vorstufen für die CVD-Erzeugung von amorphem Silicium a-SiC:H / Synthesis and Characterization of Simple α-Sila- and α,ω-Disilaalkanes: Precursors for the CVD Production of Amorphous Silicon a-SiC:H

1987 ◽  
Vol 42 (9) ◽  
pp. 1088-1096 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Cornelia Dörzbach
Keyword(s):  
Amorphous Silicon ◽  
Spectroscopic Properties ◽  
High Yield ◽  
Synthesis And Characterization ◽  
Nmr Data ◽  
Functional Derivatives ◽  
New Compounds

Preparative methods have been explored for the synthesis of small, volatile polysilaalkanes, which could serve as starting materials for the production of amorphous silicon a-SiC:H. High yield pathways have been developed for H3SiCH2CH2SiH3 and H3SiCH2CH2CH2SiH3. These compounds can be converted into symmetrically halogen-functional derivatives through the reac­tions with SnCl4 or Br2. The homologous H3SiCH2CH2SiH2CH3 has also been prepared and halogenated, starting from the corresponding vinylsilane via the hydrosilylation route. Allylsilanes were the source of the synthesis of H3SiCH2CH=CH2, CH3SiH2CH2CH=CH, SiH2(CH2CH = CH2)2, SiH2(CH2CH2CH2SiH3)2, or HSi(CH2CH2CH2SiH3)3. Methylated deriva­tives are also available. - Some physical and spectroscopic properties of the new compounds have been investigated. In particular. NMR data were collected and used for an assessment of structure and isomerism.

Isolation, characterization, and antimicrobial activity of communic acid from Juniperus phoenicea

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mariam Achir ◽  
Mohamed Dakir ◽  
Abdelhakim El Makssoudi ◽  
Asmae Belbachir ◽  
Farida Adly ◽  
...  
Keyword(s):  
Inhibition Zone ◽  
Spectroscopic Properties ◽  
High Yield ◽  
Gram Positive Bacteria ◽  
Chemical Structures ◽  
Soxhlet Apparatus ◽  
Juniperus Phoenicea ◽  
Antibacterial And Antifungal ◽  
First Time ◽  
Better Than

Abstract Objectives A mixture of Z and E communic acid is isolated for the first time from the cones of Juniperus phoenicea. Its biological activity was studied. Methods The plant material was extracted in a Soxhlet apparatus with n-hexane, the resulting extract was subjected to column chromatography (CC) on silica gel. The structure elucidation of the constituents of the isolated fraction was identified by comparison of its spectroscopic properties 1H and 13C NMR data with those reported in the literature. The antimicrobial assay of hexanic extract and isolated compounds was carried out by the disc diffusion and micro-dilution methods. Results A mixture of two diterpene acids isomers was isolated, with a high yield (68%). Their chemical structures were confirmed after comparing their spectral data with published reports. These natural products exhibited a significant antibacterial and antifungal activity against the tested strains. Indeed, for Bacillus cereus, Staphylococcus aureus, and Pseudomonas aeruginosa, the inhibition zone diameters (36–37 mm) was better than penicillin, novobiocin, and amoxicillin. For Candida albicans activity, it show that the mixture possess an activity similar to that of Metrazol. Against Escherichia coli, the inhibitory activity was found less than Amoxicillin. This is the first report of isolation of communic acid from J. phoenicea. Conclusions These results showed that the cones of J. phoenicea were an important source of communic acid, and its hexanic extract had the greatest potential antibacterial activity against both Gram-negative and Gram-positive bacteria and C. albicans.

A new diaza heteroaromatic crown of 3,5-disubstituted 1H-pyrazole which forms solid dinuclear complexes with lipophilic phenethylamines

1998 ◽  
Vol 76 (8) ◽  
pp. 1174-1179 ◽  
Author(s):  
Ana M Sanz ◽  
Pilar Navarro ◽  
Fernando Gomez-Contreras ◽  
Mercedes Pardo ◽  
Gèrard Pèpe ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Spectroscopic Properties ◽  
High Yield ◽  
Side Chain ◽  
Neutral Medium ◽  
Dinuclear Complexes ◽  
Interaction Energies ◽  
Total Interaction ◽  
The Stability ◽  
C Nmr

The cyclic stannoxane obtained from N-methyldiethanolamine and dibutyltin oxide reacts with 1H-pyrazole-3,5-dicarbonyl dichloride to afford the new 26-membered diaza tetraester crown 3. In neutral medium, the above crown forms 1:2 solid dinuclear complexes with phenethylamine (3a) and homoveratrylamine (3b), which, after crystallization from acetonitrile, were isolated in high yield (90% and 85%, respectively). The 3, 3a, and 3b structures were identified from their analytical and spectroscopic (1H, 13C NMR, and MS (FAB)) data. The spectroscopic properties of 3a and 3b are demonstrating that, in each complexation centre, simultaneously to the strong participation of the four pyrazole nitrogens, an additional weaker interaction between the aliphatic nitrogen of the side chain and the amine is involved. Comparison of the total interaction energies calculated (GenMol software) for phenethylamine-derived complex (3a) and homoveratrylamine-derived one (3b) suggests that the o-dimethoxy substitution of the guest aromatic ring could be improving the stability of 3b in relation to 3a.Key words: diazacrown, 1H-pyrazole, dinuclear, complexes, phenethylamines.

Synthetic Hydrophilic Porphyrins. Preparations and Spectra of Alkoxycarbonylmethyl and Carboxymethyl Pyridinium Porphyrins

1989 ◽  
Vol 42 (12) ◽  
pp. 2265 ◽  
Author(s):  
DP Arnold
Keyword(s):  
Aqueous Solution ◽  
Spectroscopic Properties ◽  
High Yield ◽  
Mixed Ester ◽  
Intermolecular Association ◽  
Show Evidence

The preparation and spectroscopic properties of a quaternary pyridinium porphyrin containing ethoxycarbonylmethyl groups are described. Partial saponification of the ester groups yields a series of mixed ester/carboxylate salts which show evidence of strong intermolecular association in aqueous solution. The fully saponified tetracarboxylate inner salt was prepared in high yield and has properties which conflict with a previous report.

scholarly journals Lactoperoxidase haem, an iron-porphyrin thiol

1987 ◽  
Vol 247 (1) ◽  
pp. 147-150 ◽  
Author(s):  
A W Nichol ◽  
L A Angel ◽  
T Moon ◽  
P S Clezy
Keyword(s):  
Mass Spectra ◽  
Spectroscopic Properties ◽  
Cysteine Residue ◽  
Iron Complex ◽  
Reductive Cleavage ◽  
Disulphide Bond ◽  
High Yield ◽  
Iron Porphyrin ◽  
Prosthetic Group ◽  
Mild Conditions

The haem prosthetic group of lactoperoxidase can be prepared from the enzyme in high yield by reductive cleavage with mercaptoethanol in 8 M-urea under mild conditions. The product yields porphyrins, after removal of iron, which show visible spectroscopic properties similar to protoporphyrin but are considerably more polar. In the presence of iodoacetamide, a different product is obtained by reductive cleavage. The proton n.m.r. and mass spectra of this compound indicate that the prosthetic group of the enzyme is the iron complex of 18-mercaptomethyl-2,7,12-trimethyl-3,8-divinylporphyrin-13,17-d ipropionic acid. It is proposed that the unusual strength of binding of the prosthetic group to the apoprotein is due to formation of a disulphide bond from a cysteine residue to the porphyrin thiol.

scholarly journals 15N-Etioporphyrin I and its copper complexes: Proton and electron magnetic resonance characterization

1978 ◽  
Vol 56 (19) ◽  
pp. 2598-2604 ◽  
Author(s):  
M. Momenteau ◽  
J. Mispelter ◽  
B. Loock ◽  
J. M. Lhoste
Keyword(s):  
Electron Spin Resonance ◽  
Carboxylic Acid ◽  
Copper Complexes ◽  
Zinc Complex ◽  
Resonance Spectrum ◽  
High Yield ◽  
Paramagnetic Complex ◽  
Free Base ◽  
Spin Resonance ◽  
Labelled Compound

15N-Etioporphyrin I was prepared by polycondensation of 5-hydroxymethylpyrrole-2-carboxylic acid, obtained via the Bullock route. This method gives an isomerically pure porphyrin with a high yield. The labelled compound was analyzed by nmr of the free base, of the dicationic form, and of the zinc complex. The spectrum of the free base shows a rapid tautomerism of the NH protons at 34 °C which disappears at low temperature. All spectra reveal several long-range proton—nitrogen-15 interactions. The electron spin resonance spectrum of the paramagnetic complex of this porphyrin with copper-63 is readily analyzed. This analysis was extended to the spectra of the complexes obtained with natural copper and with nitrogen-14 porphyrins.

2004 Alcan Award LectureFrom dinuclear to triakontahexanuclear complexes — Adventures in supramolecular coordination chemistry

2005 ◽  
Vol 83 (2) ◽  
pp. 77-92 ◽  
Author(s):  
Laurence K Thompson
Keyword(s):  
Self Assembly ◽  
Binding Sites ◽  
Metal Ion ◽  
Spectroscopic Properties ◽  
High Yield ◽  
Nanometer Scale ◽  
Molecular Device ◽  
Metal Centers ◽  
Supramolecular Coordination ◽  
Rational Control

Polynuclear coordination complexes result from the interplay between the arrangement of the binding sites of a ligand, and their donor content, and the coordination preferences of the metal ion involved. Rational control of the ligand properties, such as denticity, geometry, and size, can lead to large, and sometimes predictable, polynuclear assemblies. This Alcan Award Lecture highlights our "adventures" with polynucleating ligands over the last 25 years, with examples ranging from simple dinucleating to more exotic high-denticity ligands. Complexes with nuclearities ranging from 2 to 36 have been produced, many of which have novel magnetic, electrochemical, and spectroscopic properties. Self-assembly strategies using relatively simple "polytopic" ligands have been very successful in producing high-nuclearity clusters in high yield. For example, linear "tritopic" ligands produce M9 (M = Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II)) [3 × 3], flat grid-like molecules, which have quantum dot-like arrays of nine closely spaced metal centers in electronic communication. Some of these grids are discussed in terms of their novel magnetic and electrochemical properties, and also as multistable nanometer-scale platforms for potential molecular device behaviour. Bigger ligands with extended arrays of coordination pockets, and the capacity to self-assemble into much larger grids, are highlighted to illustrate our current and longer term goals of generating polymetallic molecular two-dimensional layers on surfaces.Key words: Alcan Award Lecture, transition metal, polynuclear, structure, magnetism, electrochemistry, surface studies, molecular device.

Quality films from carbon fiber evaporation for thorough coverage of TEM grids

1988 ◽  
Vol 46 ◽  
pp. 418-419
Author(s):  
N. Tempel ◽  
M. C. Ledbetter
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Carbon Films ◽  
Low Noise ◽  
Vacuum Evaporation ◽  
High Yield ◽  
Good Adhesion ◽  
Noise Structure ◽  
Resolution Electron ◽  
Carbon Foils

Carbon films have been a support of choice for high resolution electron microscopy since the introduction of vacuum evaporation of carbon. The desirable qualities of carbon films and methods of producing them has been extensively reviewed. It is difficult to get a high yield of grids by many of these methods, especially if virtually all of the windows must be covered with a tightly bonded, quality film of predictable thickness. We report here a method for producing carbon foils designed to maximize these attributes: 1) coverage of virtually all grid windows, 2) freedom from holes, wrinkles or folds, 3) good adhesion between film and grid, 4) uniformity of film and low noise structure, 5) predictability of film thickness, and 6) reproducibility.Our method utilizes vacuum evaporation of carbon from a fiber onto celloidin film and grid bars, adhesion of the film complex to the grid by carbon-carbon contact, and removal of the celloidin by acetone dissolution. Materials must be of high purity, and cleanliness must be rigorously maintained.

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