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51.
Andrey I. Poddel’sky Nikolay V. Somov Yury A. Kurskii Vladimir K. Cherkasov Gleb A. Abakumov 《Journal of organometallic chemistry》2008,693(21-22):3451-3455
The oxidative addition reaction of 4,6-di-tert-butyl-N-(2-hydroxy-3,5-di-tert-butyl-phenyl)-o-iminobenzoquinone (IBQ) to triphenylantimony(III) proceeds with the migration of hydroxyl-proton to a nitrogen atom to form tridentate O,N,O′-coordinated bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine ligand. In accordance with 1H, 13C, DEPT NMR data, the new hexacoordinate complex [bis-(3,5-di-tert-butyl-phenolate-2-yl)-amine]triphenylantimony(V), [(AP-AP)H]SbPh3 (1) in solution has a Cs symmetry plane leading to the equivalence of two O,N-chelate o-aminophenolato moieties. The molecular structure of 1 · acetone was studied by a single-crystal X-ray. Compound 1 was found to be air-stable both in solid and in solution. Its oxidation by PbO2 leads to paramagnetic [4,6-di-tert-butyl-N-(3,5-di-tert-butyl-phenolate-2-yl)-o-iminobenzosemiquinolato]triphenylantimony(V), [(AP-ISQ)]SbPh3 (2). 相似文献
52.
Alexandr V. Piskunov Arina V. Lado Ekaterina V. Ilyakina Georgii K. Fukin Evgenii V. Baranov Vladimir K. Cherkasov Gleb A. Abakumov 《Journal of organometallic chemistry》2008,693(1):128-134
New organobimetallic compounds CatSn[CpM(CO)n]2 (2-4) were obtained by the insertion of CatSn(II) (1) into the metal-metal bond of [CpM(CO)n]2 (Cat - 3,6-di-tert-butylcatecholate dianion; M = Fe (2), n = 2; M = Mo (3), W (4), n = 3). The structure of CatSn[CpMo(CO)3]2 was determined by X-ray analysis. The oxidation of compounds 2-4 with silver(I) triflate was found to produce stable paramagnetic o-semiquinolate derivatives which keep both Sn-M bonds. New paramagnetic tin(IV) complexes were investigated by EPR spectroscopy. 相似文献
53.
Piskunov AV Mescheryakova IN Fukin GK Baranov EV Hummert M Shavyrin AS Cherkasov VK Abakumov GA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(32):10085-10093
Oxidation of tin(IV) o-amidophenolate complexes [Sn(ap)Ph(2)] (1) and [Sn(ap)Et(2)(thf)] (2) (ap=dianion of 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzoquinone (ImQ)) with molecular oxygen and sulfur in toluene solutions was investigated. The reaction of oxygen with 1 at room temperature forms a paramagnetic derivative [Sn(isq)(2)Ph(2)] (3) (isq=radical anion of ImQ) and diphenyltin(IV) oxide [{Ph(2)SnO}(n)]. Interaction of 1 with sulfur gives another monophenyl-substituted paramagnetic tin(IV) complex, [Sn(ap)(isq)Ph] (4), and the sulfide, [Ph(3)Sn](2)S. The oxidation of 2 with oxygen and with sulfur proceeds through the derivative [Sn(isq)(2)Et(2)] (7), which undergoes alkyl elimination to give two new tin(IV) compounds, [Sn(ap)(isq)Et] (5) and [Sn(ap)(EtImQ)Et] (6) (EtImQ=2,4-di-tert-butyl-6-(2,6-diisopropylphenylimino)-3-ethylcyclohexa-1,4-dienolate ligand), respectively, along with the corresponding alkyltin(IV) oxide and sulfide. Complexes 3-5 and 7 were studied by EPR spectroscopy. The structures of 3, 4 and 6 were investigated by X-ray analysis. 相似文献
54.
Skirtach AG Karageorgiev P Bédard MF Sukhorukov GB Möhwald H 《Journal of the American Chemical Society》2008,130(35):11572-11573
Polymeric nanometer-thick membranes or nanomembranes possessing photocontrollable permeability are presented. Microcapsules are used as membrane model systems, while gold nanoparticle aggregates are used as active absorption centers. Upon laser light illumination the membranes change permeability reversibly because nanoparticles transiently affect the nearby polymeric network. Nanomembranes reseal to their impermeable state when the laser is switched off. This presents a novel and simple way of reversible permeability control of interest to intracellular signaling and membranes. 相似文献
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58.
Tatjana Mauser Christophe Djugnat Gleb B. Sukhorukov 《Macromolecular rapid communications》2004,25(20):1781-1785
Summary: We investigated microcapsules composed of the weak polyelectrolytes poly(allylamine hydrochloride) (PAH) and poly(methacrylic acid) (PMA) assembled on calcium carbonate cores. These capsules are stable in the pH range from 2.5 to 11.5, undergoing reversible swelling in the pH interval from 2.7 to 2.6. Capsule swelling occurs at a protonation degree above 90%. The pH‐dependent size variation of PAH/PMA capsules is blocked after crosslinking of the polyelectrolyte layers.
59.
Gleb S. Pokrovski Jean-Michel Bény Alexandre V. Zotov 《Journal of solution chemistry》1999,28(12):1307-1327
Solubilities of arsenolite (As2O3, cub.) were measured from 22 to 90°C in water–acetone, water–acetic acid, and water—formic acid solutions of compositions ranging from the pure organic compound to pure water. Raman spectra were obtained at ambient temperature on As-containing water–acetic acid and water–acetone solutions. Results show that arsenic solvation by these organic compounds is negligible and hydroxide species dominate As speciation over a wide range of water activity (aH
2
O> 0.01). The solubility data were analyzed using an approach based on stoichiometric hydration reactions. Results show that As2O3 solubility can be described as a function of water activity, independently of the nature of the organic compound, by involving two neutral As hydroxide complexes: As(OH)3 and As(OH)3·4H2O. Stability constants derived for these species indicate that hydration weakens with increasing temperature. Calculations using these constants show that at low temperatures the tetrahydrate As(OH)3·4H2O is dominant in water-rich solutions; by contrast, in high-temperature crustal fluids, As(OH)3 becomes the major As species. The proposed hydration model can be used to analyze solubility of arsenic-bearing minerals and arsenic transport in complex H2O–CO2—electrolyte solutions encountered in natural and industrial environments. 相似文献
60.
We study the dynamics of a Rouse polymer chain which diffuses in a three-dimensional space under the constraint that one of its ends, referred to as the slip-link, may move only along a one-dimensional line containing randomly placed, immobile, perfect traps. Extensions of this model occur naturally in many fields, ranging from the spreading of polymer liquids on chemically active substrates to the binding of biomolecules by ligands. For our model we succeed in computing exactly the time evolution of the probability P
sl(t) that the chain slip-link will not encounter any of the traps until time t and, consequently, that until this time the chain will remain mobile. 相似文献