Search results for "Ferrous Compounds"
showing 10 items of 47 documents
New efficient artemisinin derived agents against human leukemia cells, human cytomegalovirus and Plasmodium falciparum: 2nd generation 1,2,4-trioxane…
2015
Abstract In our ongoing search for highly active hybrid molecules exceeding their parent compounds in anticancer, antimalaria as well as antiviral activity and being an alternative to the standard drugs, we present the synthesis and biological investigations of 2nd generation 1,2,4-trioxane-ferrocene hybrids. In vitro tests against the CCRF-CEM leukemia cell line revealed di-1,2,4-trioxane-ferrocene hybrid 7 as the most active compound (IC50 of 0.01 μM). Regarding the activity against the multidrug resistant subline CEM/ADR5000, 1,2,4-trioxane-ferrocene hybrid 5 showed a remarkable activity (IC50 of 0.53 μM). Contrary to the antimalaria activity of hybrids 4–8 against Plasmodium falciparum …
Poly(N-isopropylacrylamide)-gated Fe3O4/SiO2 core shell nanoparticles with expanded mesoporous structures for the temperature triggered release of ly…
2015
Core-shell nanoparticles comprised of Fe3O4 cores and a mesoporous silica shell with an average expanded pore size of 6.07 nm and coated with a poly(N-isopropylacrylamide) (PNIPAM) layer (CS MSNs EP PNIPAM) were prepared and characterized. The nanoparticles was loaded with (Ru(bipy)3 2+) dye or an antibacterial enzyme, lysozyme, to obtain CS MSNs EP PNIPAM Ru(bipy)3 2+ and CS MSNs EP PNIPAM Lys, respectively. The lysozyme loading was determined to be 160 mg/g of nanoparticle. It was seen that Ru(bipy)3 2+ and lysozyme release was minimal at a room temperature of 25 ºC while at physiological temperature (37 º C), abrupt release was observed. The applicability of the CS MSNs EP PNIPAM Lys was…
Tetraurea calix[4]arenes with sulfur functions: synthesis, dimerization to capsules, and self-assembly on gold.
2007
Various calix[4]arene derivatives, fixed in the cone conformation by decylether groups and functionalized at their wide rim by urea residues, were synthesized. In two compounds (4f,g) sulfur functions were attached to the urea groups via different spacers in order to allow binding to metal surfaces. While they exist as single molecules in polar solvents, tetraurea calix[4]arenes of this type (4) combine to form dimeric capsules in aprotic, apolar solvents. A solvent molecule is usually included in such a capsule, if no guest with a higher affinity is present. In the presence of an equimolar amount of the tetratosylurea 5, the exclusive formation of heterodimers, consisting of one molecule o…
Ion pair recognition receptor based on an unsymmetrically 1,1'-disubstituted ferrocene-triazole derivative.
2012
The ferrocene-triazole derivative 4, available from 1,1'-bis(diazido)ferrocene by sequential functionalization through click-type chemistry and the Staudinger reaction, is elaborated as a lab-on-a-molecule for the selective sensing of HP(2)O(7)(3-) and Hg(2+). Receptor 4 behaves as a ratiometric fluorescent probe for HP(2)O(7)(3-) with a good selectivity over other anions, whereas in the presence of Hg(2+) it modifies the fluorescent emission of the pyrene unit, acting as a selective on-off fluorescent sensor for Hg(2+) with a low detection limit. The most salient feature of compound 4 is its behavior as an excellent electrooptical ion pair recognition receptor able to simultaneously recogn…
Intramolecular electron transfer between molybdenum and iron mimicking bacterial sulphite dehydrogenase
2014
Diferrocenyl/diferrocenium substituted dioxido molybdenum(VI) complexes [Fe2MoO2] 2(Fc)/[2(FC)]²⁺ mimic the catalytic active site including the redox subunits as well as the catalytic function of bacterial sulphite oxidases.
Effect of acidosis and anoxia on iron delocalization from brain homogenates.
1992
Abstract Cortical homogenates were prepared from rat brain in Krebs-Ringer phosphate media adjusted to pH 7, 6 or 5 and incubated for 1 hr under aerotic or anaerobic conditions in the presence of dipyridyl, an iron chelator. Low molecular weight species (LMWS) iron was measured spectrophotometrically after passing of the homogenates through a 10,000- M , ultrafiltration membrane. Following aerobic incubation, LMWS iron reached 1.24 μg/g tissue at pH 7, and increased 1.7-fold at pH 6 and 3.1-fold at pH 5. Anoxia enhanced significantly the amount of ultrafiltrable iron at the three pH values, the LMWS iron level being increased by 190% at pH 7, by 113% at pH 6, and by 77% at pH 5. Addition of…
Identification of carbonate-rich outcrops on Mars by the Spirit rover.
2010
Ancient Carbonate Minerals on Mars The historical presence of liquid water on Mars together with a CO 2 -rich atmosphere should have resulted in the accumulation of large deposits of carbonate minerals. Yet, evidence for the presence of carbonates on the surface of Mars has been scarce. Using data collected by the Mars Exploration Rover, Spirit, Morris et al. (p. 421 , published online 3 June; see the Perspective by Harvey ) now present evidence for carbonate-rich outcrops in the Comanche outcrops within the Gusev crater. The carbonate is a major outcrop component and may have formed in the Noachian era (∼4 billion years ago) by precipitation from hydrothermal solutions that passed through …
Coordination polymers based on diiron tetrakis(dithiolato) bridged by alkali metals, electrical bistability around room temperature, and strong antif…
2015
Coordination polymer chains have been formed by the direct reaction between HSC6H2Cl2SH and FeCl3·6H2O in the presence of an aqueous solution of the corresponding alkali-metal hydroxide (M = Li, Na, and K) or carbonate (M = Rb and Cs). The structures consist of dimeric [Fe2(SC6H2Cl2S)4](2-) entities bridged by [M2(THF)4] [M = K (1), Rb (2), and Cs (3); THF = tetrahydrofuran] or {[Na2(μ-H2O)2(THF)2] (5 and 5') units. The smaller size of the lithium atom yields an anion/cation ion-pair molecule, [Li(THF)4]2[Fe2(SC6H2Cl2S)4] (4), in which the dianionic moieties are held together by Cl···Cl interactions. Electrical characterization of these compounds shows a general semiconductor behavior in wh…
New concepts in multidentate ligand chemistry: effects of multidentarity on catalytic and spectroscopic properties of ferrocenyl polyphosphines.
2008
This tutorial review devoted to ligand chemistry deals with the design and properties of ferrocenyl polyphosphines, an original class of multidentate ligands. The development of a varied library of ferrocenyl tetra-, tri- and diphosphine ligands is reviewed. The multidentate nature of these species has led to unique spectroscopic and catalytic properties, in which the spatial proximity of phosphorus atoms is crucial. Regarding their catalytic applications, the key issues of catalyst longevity and ultralow catalyst loadings are discussed. Another part is concerned with fundamental advances gained in physical chemistry for structure elucidation by the study of the intriguing “through-space” N…
Ferrocene compounds: methyl 1′-aminoferrocene-1-carboxylate
2010
The title compund, [Fe(C(5)H(6)N)(C(7)H(7)O(2))], features one strong intermolecular hydrogen bond of the type N-H...O=C [N...O = 3.028 (2) A] between the amine group and the carbonyl group of a neighbouring molecule, and vice versa, to form a centrosymmetric dimer. Furthermore, the carbonyl group acts as a double H-atom acceptor in the formation of a second, weaker, hydrogen bond of the type C-H...O=C [C...O = 3.283 (2) A] with the methyl group of the ester group of a second neighbouring molecule at (x, -y - 1/2, z - 1/2). The methyl group also acts as a weak hydrogen-bond donor, symmetry-related to the latter described C-H...O=C interaction, to a third molecule at (x, -y - 1/2, z + 1/2) t…