首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
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   

2.
《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   

3.
4.
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   

5.
6.
7.
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   

8.
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   

9.
The three title compounds tri‐μ‐carbonyl‐1:2κ2C;1:3κ2C;2:3κ2C‐octacarbonyl‐1κC,2κ2C,3κ2C,4κ3C‐η5‐methylcyclopentadienyl‐tetrahedro‐triiridiummolybdenum(3 IrIr)(3 IrMo), tri‐μ‐carbonyl‐1:2κ2C;1:3κ2C;2:3κ2C‐octacarbonyl‐1κC,2κ2C,3κ2C,4κ3C‐η5‐tetramethylcyclopentadienyl‐tetrahedro‐triiridiummolybdenum(3 IrIr)(3 IrMo) and tri‐μ‐carbonyl‐1:2κ2C;1:3κ2C;2:3κ2C‐octacarbonyl‐1κC,2κ2C,3κ2C,4κ3C‐η5‐pentamethylcyclopentadienyl‐tetrahedro‐triiridiummolybdenum(3 IrIr)(3 IrMo), [MoIr35‐C5H5?nMen)(μ‐CO)3(CO)8], where n = 1, 4 or 5, have a pseudo­tetrahedral MoIr3 core geometry, with a η5‐C5H5?nMen group ligating the Mo atom, bridging carbonyls spanning the edges of an MoIr2 face, and eight terminally bound carbonyls.  相似文献   

10.
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   

11.
12.
The crystal structures of tris(2‐methyl­quinolin‐8‐olato‐N,O)­iron(III), [Fe­(C10­H8­NO)3], (I), and aqua­bis(2‐methyl­quinolin‐8‐olato‐N,O)­copper(II), [Cu­(C10­H8NO)2­(H2O)], (II), have been determined. Compound (I) has a distorted octahedral configuration, in which the central Fe atom is coordinated by three N atoms and three O atoms from three 2‐methylquinolin‐8‐olate ligands. The three Fe—O bond distances are in the range 1.934 (2)–1.947 (2) Å, while the three Fe—N bond distances range from 2.204 (2) to 2.405 (2) Å. In compound (II), the central CuII atom and H2O group lie on the crystallographic twofold axis and the coordination geometry of the CuII atom is close to trigonal bipyramidal, with the three O atoms in the basal plane and the two N atoms in apical positions. The Cu—N bond length is 2.018 (5) Å. The Cu—O bond length in the basal positions is 1.991 (4) Å, while the Cu—O bond length in the apical position is 2.273 (6) Å. There is an intermolecular OW—H?O hydrogen bond which links the mol­ecules into a linear chain along the b axis.  相似文献   

13.
The structures of [Cu(AA)6](ClO4)2, (I), and [Mn(AA)6](ClO4)2, (II) (AA is acrylamide, also known as prop‐2‐enamide; C3H5NO), display both intra‐ and intermolecular N—H...O hydrogen bonding. A three‐dimensional network is propagated via the perchlorate counter‐ions. There are two crystallographically independent molecules in the copper complex, with the most significant difference between them being the conformation of one symmetry‐related pair of AA ligands which are in the unusual syn conformation. The copper complex exhibits syn/anti disorder of the =CH2 group in one pair of symmetry‐related AA ligands. The CuII and MnII centres are both situated on centres of inversion. The copper complex cation has octahedral coordination geometry with typical Jahn–Teller distortions.  相似文献   

14.
15.
meso‐Nitrosubporphyrinatoboron(III) was synthesized by nitration of meso‐free subporphyrin with AgNO2/I2. The subsequent reduction with a combination of NaBH4 and Pd/C gave meso‐aminosubporphyrinatoboron(III). meso‐Nitro‐ and meso‐amino‐groups significantly influenced the electronic properties of subporphyrin, which has been confirmed by NMR and UV/Vis spectra, electrochemical analysis, and DFT calculations. Oxidation of meso‐aminosubporphyrinatoboron(III)s with PbO2 cleanly gave meso‐to‐meso azosubporphyrinatoboron(III)s that exhibited almost coplanar conformations and large electronic interaction through the azo‐bridge.  相似文献   

16.
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   

17.
18.
Tetraaqua(18‐crown‐6)cerium(III) hexacyanoferrate(III) dihydrate, [Ce(C12H24O6)(H2O)4][Fe(CN)6]·2H2O, and tetraaqua(18‐crown‐6)neodymium(III) hexacyanoferrate(III) dihydrate, [Nd(C12H24O6)(H2O)4][Fe(CN)6]·2H2O, are isomorphous and isostructural in the C2/c space group, where the cations, which contain ten‐coordinate lanthanoid centres, lie across twofold rotation axes and the anions lie across inversion centres. In these compounds, an extensive series of O—H...O and O—H...N hydrogen bonds links the components into a continuous three‐dimensional framework. Triaqua(18‐crown‐6)lanthanoid(III) hexacyanoferrate(III) dihydrate, [Ln(C12H24O6)(H2O)3][Fe(CN)6]·2H2O, where Ln = Sm, Eu, Gd or Tb, are all isomorphous and isostructural in the P space group, as are triaqua(18‐crown‐6)gadolinium(III) hexacyanochromate(III) dihydrate, [Gd(C12H24O6)(H2O)3][Cr(CN)6]·2H2O, and triaqua(18‐crown‐6)gadolinium(III) hexacyanocobaltate(III) dihydrate, [Gd(C12H24O6)(H2O)3][Co(CN)6]·2H2O. In these compounds, there are two independent anions, both lying across inversion centres, and the lanthanoid centres exhibit nine‐coordination; in the crystal structures, an extensive series of hydrogen bonds links the components into a three‐dimensional framework.  相似文献   

19.
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   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号