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Steffi Friedrichs Peter G. Jones 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):56-57
Both ions of the title compound, [Au(C4H8S)2](C6H4NO4S2), display crystallographic twofold symmetry. The Au atom exhibits linear coordination, with Au—S = 2.2948 (14) Å and S—Au—S = 178.47 (9)°. The crystal packing consists of layers of anions connected by C—H?O hydrogen bonds; the cations occupy cavities in these layers and the ions are linked by Au?N contacts of 3.009 (7) Å. Further C—H?O interactions connect the layers. 相似文献
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Paul V. Bernhardt Brendan P. Macpherson 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):m533-m536
The crystal structures of a pair of closely related macrocyclic cyano‐ and hydroxopentaaminecobalt(III) complexes, as their perchlorate salts, are reported. Although the two complexes, [Co(CN)(C11H27N5)](ClO4)2·H2O and [Co(OH)(C11H27N5)](ClO4)2, exhibit similar conformations, significant differences in the Co—N bond lengths arise from the influence of the sixth ligand (cyano as opposed to hydroxo). The ensuing hydrogen‐bonding patterns are also distinctly different. Disorder in the perchlorate anions was clearly resolved and this was rationalized on the basis of distinct hydrogen‐bonding motifs involving the anion O atoms and the N—H and O—H donors. 相似文献
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Katja Jankova Jrgen Kops Xianyi Chen Walther Batsberg 《Macromolecular rapid communications》1999,20(4):219-223
Diblock copolymers of poly(ethylene‐co‐butylene) and polystyrene or poly(4‐acetoxystyrene) are synthesized by atom transfer radical polymerization (ATRP) using a 2‐bromopropionic ester macroinitiator prepared from commercial monohydroxyl functional narrow dispersity hydrogenated polybutadiene (Kraton Liquid Polymer, L‐1203). ATRP carried out in bulk and in xylene solution with cuprous bromide and two different complexing agents 2,2′‐bipyridine (bipy) and 1,1,4,7,10,10‐hexamethyltriethylenetetraamine (HMTETA) yielded well‐defined diblock copolymers with polydispersities around 1,3. The diblock copolymer with poly(4‐acetoxystyrene) was hydrolyzed to the corresponding poly(4‐hydroxystyrene) sequence. 相似文献
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Theivanayagam C. Deivaraj Jagadese J. Vittal 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):775-776
In the title compound, [Ni(C2H3OS)2(C18H15P)2], the Ni atom lies on an inversion centre and the triphenyl phosphine and thioacetate ligands are bonded to the central NiII atom in a trans fashion, with Ni—S = 2.2020 (8) and Ni—P = 2.2528 (8) Å, and angle S—Ni—P = 92.47 (3)°. 相似文献
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Insertion of Rhodizonic Acid into the Gallium‐Gallium and Indium‐Indium Bonds of Digallane(4) and Diindane(4) Compounds Rhodizonic acid (C6O6H2, 5, 6‐dihydroxy‐5‐cyclohexene‐1, 2, 3, 4‐tetraone) did not react with tetrakis[bis(trimethylsilyl)methyl] digallane(4) ( 1 ) and the corresponding diindium compound ( 2 ) by the transfer of protons. Instead the acid was completely inserted into the element‐element bonds of the starting compounds and the gallium or indium atoms were oxidized from the oxidation state of +II to +III. In contrast to the free acid, the OH groups of the products are not attached to neighbouring carbon atoms, but occupy the 1, 4‐positions of the central six‐membered rings. Both dialkylgallium and dialkylindium groups of the products ( 3 (Ga) and 4 (In)) are coordinated by two oxygen atoms. They adopt opposite positions at the C6O6 molecular core. 相似文献
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Inside Cover: New Chiral Reagent for Installation of Pharmacophoric (S)‐ or (R)‐2‐(Alkoxyphosphono)‐1‐amino‐2,2‐difluoroethyl Groups (Chem. Eur. J. 21/2016) 下载免费PDF全文
Chen Xie Lijun Zhang Dr. Haibo Mei Dr. Romana Pajkert Dr. Maksym Ponomarenko Dr. Yi Pan Prof. Dr. Gerd‐Volker Röschenthaler Prof. Dr. Vadim A. Soloshonok Dr. Jianlin Han 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):6990-6990
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To create a novel vector for specifically delivering anticancer therapy to solid tumors, we used diafiltration to synthesize pH‐sensitive polymeric micelles. The micelles, formed from a tetrablock copolymer [poly(ethylene glycol)‐b‐poly(L ‐histidine)‐b‐poly(L ‐lactic acid)‐b‐poly(ethylene glycol)] consisted of a hydrophobic poly(L ‐histidine) (polyHis) and poly(L ‐lactic acid) (PLA) core and a hydrophilic poly(ethylene glycol) (PEG) shell, in which we encapsulated the model anticancer drug doxorubicin (DOX). The robust micelles exhibited a critical micellar concentration (CMC) of 2.1–3.5 µg/ml and an average size of 65–80 nm pH 7.4. Importantly, they showed a pH‐dependent micellar destabilization, due to the concurrent ionization of the polyHis and the rigidity of the PLA in the micellar core. In particular, the molecular weight of PLA block affected the ionization of the micellar core. Depending on the molecular weight of the PLA block, the micelles triggering released DOX at pH 6.8 (i.e. cancer acidic pH) or pH 6.4 (i.e. endosomal pH), making this system a useful tool for specifically treating solid cancers or delivering cytoplasmic cargo in vivo. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Nadia M. Comerlato William T. A. Harrison R. Alan Howie John Nicolson Low Alexandre C. Silvino James L. Wardell Solange M. S. V. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):m105-m108
The title compounds are salts of the general form (Q+)2[Zn(dmit)2]2?, where dmit corresponds to the ligand (C3S5)? present in both and Q+ to the counter‐cations (nBu4N)+ [or C16H36N+] and (Ph4As)+ [or C24H20As+], respectively. In the first case, Zn is in the 4e special positions of space group C2/c and hence the [Zn(dmit)2]2? dianion possesses twofold axial crystallographic symmetry. Including these, there are now 11 known examples of [Zn(dmit)2]2? or its analogues, with O replacing the exocyclic thione S, and [Zn(dmio)2]2? dianions in nine structures with various Q. Comparison of these reveals a remarkable variation in details of the conformation which the dianion may adopt in terms of Zn coordination, equivalence of the Zn—S bond lengths, displacement of Zn from the plane of the ligand and overall dianion shape. 相似文献
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《化学:亚洲杂志》2017,12(22):2929-2941
In contrast to diradicals connected by alternant hydrocarbons, only a few studies on those connected by nonalternant hydrocarbons have been reported. The syntheses, structures, and magnetic properties of azulene‐1,3‐diyl linked bis(nitronyl nitroxide) (NN2Az) and bis(iminonitroxide) (IN2Az) diradicals and their Cu(hfac)2 (hfac=hexafluoroacetylacetonate) complexes were investigated. NN2Az was shown to have an intramolecular ferromagnetic interaction with J obs/k B=+10.0 K (H =−2J S 1 ⋅S 2) between (nitronyl nitroxide) spins, whereas IN2Az was estimated to have a much weaker intramolecular magnetic interaction. The reactions of NN2Az and IN2Az with Cu(hfac)2 gave a 1:2 [{Cu(hfac)2}2(NN2Az)] complex and a 1:1 [Cu(hfac)2(IN2Az)] ⋅ C6H12 complex, respectively. [{Cu(hfac)2}2(NN2Az)] showed strong intramolecular antiferromagnetic interactions (J 1‐Cu‐R/k B≈−800 K, J 2‐Cu‐R/k B≈−500 K) between the CuII spins and the coordinating NN spins, whereas [Cu(hfac)2(IN2Az)] exhibited a ferromagnetic exchange interaction (J obs‐Cu‐R/k B=+114 K) between the CuII spin and the imino‐coordinated iminonitroxide spin. 相似文献
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Hideto Tsuji Yasufumi Tezuka Kazunobu Yamada 《Journal of Polymer Science.Polymer Physics》2005,43(9):1064-1075
Films of poly(L ‐lactide‐co‐D ‐lactide) [P(LLA‐DLA); 95/5] and poly(L ‐lactide) [i.e., poly(L ‐lactide acid) (PLLA)] were prepared by crystallization from the melt, and a comparative study of the crystallization effects on the alkaline and proteinase K catalyzed hydrolysis of the films was carried out. The hydrolyzed films were investigated with gravimetry, differential scanning calorimetry, polarimetry, and gel permeation chromatography, and the results were compared with those reported for amorphous‐made specimens. The alkaline hydrolyzability of the P(LLA‐DLA) (95/5) and PLLA films was determined solely by the initial crystallinity (Xc) and was not affected by the content of the incorporated D ‐lactide (DLA) unit in the polymer chain; this was in marked contrast to the fact that the enzymatic hydrolyzability depended on not only the initial Xc value but also the DLA unit content. The alkaline hydrolysis rate of the P(LLA‐DLA) (95/5) and PLLA films and the enzymatic hydrolysis rate (REH) of the P(LLA‐DLA) (95/5) films decreased linearly as the initial Xc value increased. This meant that the hydrolyzability of the restricted amorphous regions was very similar to that of the free amorphous regions. In contrast, REH of the PLLA films decreased nonlinearly with the initial Xc value, and this nonlinear dependence was caused by the fact that in the PLLA films the restricted amorphous regions were much more hydrolysis‐resistant than the free amorphous regions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1064‐1075, 2005 相似文献