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Kurt Merzweiler - One of the best experts on this subject based on the ideXlab platform.
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Synthese und Kristallstrukturen der neuen Zinn-Chalkogen-Vierringe [{Cp(Ph3P)Ni}2Cl2Sn2E2] (E = Se, S) / Synthesis and Crystal Structures of the New Four-M em bered Tin-Chalcogen Rings [{Cp(Ph3P)Ni}2Cl2Sn2E2] (E = Se, S)
Zeitschrift für Naturforschung B, 1997Co-Authors: Harald Kraus, Kurt MerzweilerAbstract:[{Cp(Ph₃P)Ni}SnCl₃] reacts with Se(SiMe₃)₂ within several days to give [{Cp₄(Ph₃P)₃Ni₅Sn₆Se₉] (1). If the reaction is stopped after 16h, green crystals of the intermediate [{Cp(Ph₃P)Ni}₂Cl₂Sn₂Se₂] (2) can be isolated. According to the X -ray structure determination, 2 consists of a planar Sn₂Se₂ ring with terminal {Cp(Ph₃P)Ni} and Cl substituents in a trans arrangement. The analogous reaction of [{Cp(Ph₃P)Ni}SnCl₃] with S(SiMe₃)₂ leads to the Sulfur Derivative [{Cp(Ph₃P)Ni}₂Cl₂Sn₂S₂] 3 which has an analogous structure.
Harald Kraus - One of the best experts on this subject based on the ideXlab platform.
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Synthese und Kristallstrukturen der neuen Zinn-Chalkogen-Vierringe [{Cp(Ph3P)Ni}2Cl2Sn2E2] (E = Se, S) / Synthesis and Crystal Structures of the New Four-M em bered Tin-Chalcogen Rings [{Cp(Ph3P)Ni}2Cl2Sn2E2] (E = Se, S)
Zeitschrift für Naturforschung B, 1997Co-Authors: Harald Kraus, Kurt MerzweilerAbstract:[{Cp(Ph₃P)Ni}SnCl₃] reacts with Se(SiMe₃)₂ within several days to give [{Cp₄(Ph₃P)₃Ni₅Sn₆Se₉] (1). If the reaction is stopped after 16h, green crystals of the intermediate [{Cp(Ph₃P)Ni}₂Cl₂Sn₂Se₂] (2) can be isolated. According to the X -ray structure determination, 2 consists of a planar Sn₂Se₂ ring with terminal {Cp(Ph₃P)Ni} and Cl substituents in a trans arrangement. The analogous reaction of [{Cp(Ph₃P)Ni}SnCl₃] with S(SiMe₃)₂ leads to the Sulfur Derivative [{Cp(Ph₃P)Ni}₂Cl₂Sn₂S₂] 3 which has an analogous structure.
Gian Franco Pedulli - One of the best experts on this subject based on the ideXlab platform.
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antioxidant profile of ethoxyquin and some of its s se and te analogues
Journal of Organic Chemistry, 2007Co-Authors: Sangi Kuma, Lars Engma, Luca Valgimigli, Riccardo Amorati, Maria Grazia Fumo, Gian Franco PedulliAbstract:(Chemical Equation Presented) 6-(Ethylthio)-, 6-(ethylseleno)-, and 6-(ethyltelluro)-2,2,4-trimethyl-1,2-dihydroquinoline-three heavier chalcogen analogues of ethoxyquin-were prepared by dilithiation of the corresponding 6-bromodihydroquinoline followed either by treatment with the corresponding diethyl dichalcogenide (Sulfur Derivative) or by insertion of selenium/tellurium into the carbon-lithium bond, oxidation to a diaryl dichalcogenide, borohydride reduction, and finally alkylation of the resulting areneselenolate/ arenetellurolate. Ethoxyquin, its heavier chalcogen analogues, and the corresponding 6-PhS, 6-PhSe, and 6-PhTe Derivatives were assayed for both their chain-breaking antioxidant capacity and their ability to catalyze reduction of hydrogen peroxide in the presence of a stoichiometric amount of a thiol reducing agent (thiol peroxidase activity). Ethoxyquin itself turned out to be the best inhibitor of azo-initiated peroxidation of linoleic acid in a water/chlorobenzene two-phase system. In the absence of N-acetylcysteine as a coantioxidant in the aqueous phase, it inhibited peroxidation as efficiently as α-tocopherol but with a more than 2-fold longer inhibition time. In the presence of 0.25 mM coantioxidant in the aqueous phase, the inhibition time was further increased by almost a factor of 2. This is probably due to thiol-mediated regeneration of the active antioxidant across the lipid-aqueous interphase. The ethyltelluro analogue 1d of ethoxyquin was a similarly efficient quencher of peroxyl radicals compared to the parent in the two-phase system, but less regenerable. Ethoxyquin was found to inhibit azo-initiated oxidation of styrene in the homogenous phase (chlorobenzene) almost as efficiently (k inh = (2.0 ± 0.2) × 106 M-1 s -1) as α-tocopherol with a stoichiometric factor n = 2.2 ± 0.1. At the end of the inhibition period, autoxidation was additionally retarded, probably by ethoxyquin nitroxide formed during the course of peroxidation. The N-H bond dissociation enthalpy of ethoxyquin (81.3 ± 0.3 kcal/mol) was determined by a radical equilibration method using 2,6-dimethoxyphenol and 2,6-di-tert-butyl-4-methylphenol as equilibration partners. Among the investigated compounds, only the tellurium analogues 1d and, less efficiently, 1g had a capacity to catalyze reduction of hydrogen peroxide in the presence of thiophenol. Therefore, analogue 1d is the only antioxidant which is multifunctional (chain-breaking and preventive) in character and which can act in a truly catalytic fashion to decompose both peroxyl radicals and organic hydroperoxides in the presence of suitable thiol reducing agents.
Morteza Moradi - One of the best experts on this subject based on the ideXlab platform.
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Mercuric chloride adsorption on Sulfur-containing BC_2N nanotube: toward HSAB concept
Structural Chemistry, 2014Co-Authors: Morteza MoradiAbstract:Electronic sensitivity of pristine and Sulfur-containing BC_2N nanotubes to mercuric chloride (HgCl_2) molecule was investigated by utilizing density functional theory. It was found that HgCl_2 is weakly adsorbed on the tube, releasing energy of 6.4–8.1 kcal/mol, and electronic properties of the tube are not significantly changed. To overcome this problem, carbon atoms of the tube were substituted by Sulfur atom. Of interest are Sulfur Derivative functional adsorbents because of their strong affinity toward mercury. This observation may be explained based on the Pearson’s hard–soft acid–base theory. It was demonstrated that the S-doped tube can not only strongly adsorb the HgCl_2 molecule, but also may effectively detect its presence due to drastic increment of the tube electrical conductivity.
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Mercuric chloride adsorption on Sulfur-containing BC2N nanotube: toward HSAB concept
Structural Chemistry, 2013Co-Authors: Morteza MoradiAbstract:Electronic sensitivity of pristine and Sulfur-containing BC2N nanotubes to mercuric chloride (HgCl2) molecule was investigated by utilizing density functional theory. It was found that HgCl2 is weakly adsorbed on the tube, releasing energy of 6.4–8.1 kcal/mol, and electronic properties of the tube are not significantly changed. To overcome this problem, carbon atoms of the tube were substituted by Sulfur atom. Of interest are Sulfur Derivative functional adsorbents because of their strong affinity toward mercury. This observation may be explained based on the Pearson’s hard–soft acid–base theory. It was demonstrated that the S-doped tube can not only strongly adsorb the HgCl2 molecule, but also may effectively detect its presence due to drastic increment of the tube electrical conductivity.
Jesús Valdés-martínez - One of the best experts on this subject based on the ideXlab platform.
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Complexes of In(III) with tetraphenylimidodiphosphinate ligands
Monatshefte für Chemie Chemical Monthly, 1992Co-Authors: Raymundo Cea-olivares, Rubén A. Toscano, Gabriela Carreón, Jesús Valdés-martínezAbstract:Es wird über die Synthese und Charakterisierung der anorganischen heterocyclischen Komplexe In(OP Ph _2NP Ph _2O)_3 und In(SP Ph _2NP Ph _2S)_3 berichtet. Die Struktur des Schwefelderivates wurde mit röntgenographischen Methoden bestimmt. Der Komplex gehört einer verdrillten Oh Symmetrie an und wird mit dem Bi(II)-Analog verglichen. Die^31P-NMR-Daten und die Röntgenstruktur legen nahe, daß die raumbeanspruchenden Liganden für die Geometrie dieser Komplexe verantwortlich sind und daher bei der Struktur des Bi(II)-Analogen die freien Elektronenpaare eine untergeordnete Rolle spielen. We report the synthesis and characterization of the inorganic heterocyclic complexes In(OP Ph _2NP Ph _2O)_3 and In(SP Ph _2NP Ph _2S)_3. The structure of the Sulfur Derivative was determined by X-ray methods. The complex presents a distorted Oh symmetry and it is compared with the Bi(III) analog. The^31P-NMR data and the X-ray structural determination suggest that the bulky ligands are responsible for the geometrical features in these complexes and therefore, for the Bi(III) analogs perhaps the lone pair does not play an important role in the structure.
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Complexes of In(III) with tetraphenylimidodiphosphinate ligands
Monatshefte f�r Chemie Chemical Monthly, 1992Co-Authors: Raymundo Cea-olivares, Rubén A. Toscano, Gabriela Carreón, Jesús Valdés-martínezAbstract:We report the synthesis and characterization of the inorganic heterocyclic complexes In(OPPh2NPPh2O)3 and In(SPPh2NPPh2S)3. The structure of the Sulfur Derivative was determined by X-ray methods. The complex presents a distorted Oh symmetry and it is compared with the Bi(III) analog. The31P-NMR data and the X-ray structural determination suggest that the bulky ligands are responsible for the geometrical features in these complexes and therefore, for the Bi(III) analogs perhaps the lone pair does not play an important role in the structure.
