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81.
G. O. Schulz R. Milkovich 《Journal of polymer science. Part A, Polymer chemistry》1984,22(7):1633-1652
Copolymerization studies of methacrylate-terminated polystyrene macromonomers (M1) with several comonomers (M2) verified the modified kinetic scheme and permitted prediction of graft polymer compositions and structures. Instantaneous and cumulative copolymer compositions, average graft distributions, and grafts per molecule are predicted from FORTRAN IV or BASIC programs. The r2 relative reactivity ratios determined from styrene copolymerization (0.61) or from low conversion acrylic monomer in aqueous suspension (~0.4) had good agreement with literature values (about 0.6 and 0.4, respectively). Decreased macromonomer reactivity determined at high acrylic monomer conversions was attributed to phase separation phenomena. The Macromers also exhibited lower reactivity than predicted when copolymerized with acrylic monomers in DMSO/benzene solutions (r2 ~ 0.8). 相似文献
82.
Heinz Berner Gerhard Schulz Gernot Fischer Hellmuth Reinshagen 《Monatshefte für Chemie / Chemical Monthly》1978,109(3):557-566
In order to obtain a better partition of a prodigiosin derivative in biological media, two hydroxy groups were introduced into theansa-part of the molecule. The synthesis of the title compound is described in detail. 相似文献
83.
Axel Schulz Thomas M. Klap tke
T. Stanley Cameron
P. K. Bakshi 《Journal of organometallic chemistry》1994,480(1-2):191-194The oxidation of Cp2NbCl2 with pure WF6 in SO2 solution yielded the cationic metallocene species [Cp2NbCl2]+[WF6]− essentially in quantitative yield. The same reaction carried out in the presence of either equimolar amounts or a two-fold excess of HCN led to the preparation of the new niobocenium salt [Cp2NbCl2]4+[WF6]2− which was studied by single crystal X-ray diffraction. This compound represents the first example of a structurally characterized metallocene-WF6− complex, and crystallizes in the tetragonal system: space group, P41212(No. 92), a = 11.083(8) Å, c = 48.285 (9) Å; Z = 8; R = 0.0759, RW = 0.0841. ab]Die Oxidation von Cp2NbCl2 mit reinem WF6 führt in SO2-Lösung zur Synthese von [Cp2NbCl2 ]+[WF6]− in nahezu quantitativer Ausbeute. Die analoge Reaktion führt unter Anwesenheit der äquimolaren Menge oder eines zweifachen Überschusses an HCN zur Ausbildung des Niobocenium-Komplexsalzes [Cp2NbCl2]4+ [WF6]2−[WCl6]2−, von dem eine Röntgenstrukturanalyse angefertigt wurde. Diese Verbindung repräsentiert den ersten structurell charakterisierten Vertreter eines Metallocen-WF6−-Komplexes und kristallisiert im tetragonalen System: Raumgruppe P41212 (Nr. 92), a = 11.083(8) Å, c = 48.285(9) Å; Z = 8; R = 0.0759, RW = 0.0841. kw]Niobium; X-ray diffraction; Oxidation; Metallocenes 相似文献
84.
85.
86.
Michael I. Bruce Michael Schulz Brian W. Skelton Allan H. White 《Journal of Cluster Science》2000,11(1):79-86
Addition of aqueous HCl to Ru5(
3-C=CH2)(-SMe)2(-PPh2)2(CO)10 afforded the structurally characterized carbyne complex Ru5(
3-SMe)(
3-CMe)(-Cl)(-SMe)(-PPh2)2(CO)9, formed by addition of H to the vinylidene ligand; a Cl atom bridges an Ru–Ru bond. 相似文献
87.
88.
Zhenhui Qi Dr. Changzhu Wu Dr. Paula Malo de Molina Han Sun Andrea Schulz Prof. Christian Griesinger Prof. Michael Gradzielski Prof. Rainer Haag Prof. Marion B. Ansorge‐Schumacher Prof. Christoph A. Schalley 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(31):10150-10159
A new and versatile, crown ether appended, chiral supergelator has been designed and synthesized based on the bis‐urea motif. The introduction of a stereogenic center improved its gelation ability significantly relative to its achiral analogue. This low‐molecular‐weight gelator forms supramolecular gels in a variety of organic solvents. It is sensitive to multiple chemical stimuli and the sol–gel phase transitions can be reversibly triggered by host–guest interactions. The gel can be used to trap enzymes and release them on demand by chemical stimuli. It stabilizes the microparticles in Pickering emulsions so that enzyme‐catalyzed organic reactions can take place in the polar phase inside the microparticles, the organic reactants diffusing through the biphasic interface from the surrounding organic phase. Because of the higher interface area between the organic and polar phases, enzyme activity is enhanced in comparison with simple biphasic systems. 相似文献
89.
A chemical reaction mechanism was developed for the formation of iron oxide (Fe2O3) from iron pentacarbonyl (Fe(CO)5) in a low‐pressure hydrogen–oxygen flame reactor. In this paper, we describe an extensive approach for the flame‐precursor chemistry and the development of a novel model for the formation of Fe2O3 from the gas phase. The detailed reaction mechanism is reduced for the implementation in two‐dimensional, reacting flow simulations. The comprehensive simulation approach is completed by a model for the formation and growth of the iron oxide nanoparticles. The exhaustive and compact reaction mechanism is validated using experimental data from iron‐atom laser‐induced fluorescence imaging. The particle formation and growth model are verified with new measurements from particle mass spectrometry. 相似文献
90.
Mariam Abd El Sater Dr. Mohamed Mellah Dr. Diana Dragoe Emilie Kolodziej Dr. Nada Jaber Dr. Emmanuelle Schulz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(36):9454-9460
The first immobilization of a pyrene-tagged chromium salen complex through π-π noncovalent interactions on reduced graphene oxide (rGO) is described. A very robust supported catalytic system is obtained to promote asymmetric catalysis in repeated cycles, without loss of activity or enantioselectivity. This specific behavior was demonstrated in two different catalytic reactions (up to ten reuses) promoted by chromium salen complexes, the cyclohexene oxide ring-opening reaction and the hetero-Diels-Alder cycloaddition between various aldehydes and Danishefsky's diene. Furthermore, the chiral chromium salen@rGO has been found to be compatible with a multi-substrate type use, in which the structure of the substrate involved is modified each time the catalyst is reused. 相似文献