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1.
Single crystals of the title compound are obtained from a mixture of Sc2S3, Rb2MoS4, MoS2, and Mo (Mo crucible, 1773 K, 48 h).  相似文献   

2.
The monoclinic compound Cr1.45Tl1.87Mo15Se19 (chromium thallium pentadecamolybdenum nonadecaselenide) represents a variant of the hexagonal In3Mo15Se19 structure type. Its crystal structure consists of an equal mixture of Mo6Se8Se6 and Mo9Se11Se6 cluster units. The Mo and Se atoms of the median plane of the Mo9Se11Se6 unit, as well as three Cr ions, lie on sites with m symmetry (Wyckoff site 2e). The fourth Cr ion is in a 2b Wyckoff position with site symmetry.  相似文献   

3.
The crystal structure of dicaesium pentadecamolybdenum nonadeca­sulfide, Cs2Mo15S19, consists of a mixture of Mo6S8S6 and Mo9S11S6 cluster units in a 1:1 ratio. Both units are interconnected via inter‐unit Mo—S bonds. The Cs+ cations occupy large voids between the different cluster units. The Cs and two inner S atoms lie on sites with 3 symmetry (Wyckoff site 12c) and the Mo and S atoms of the median plane of the Mo9S11S6 cluster unit on sites with 2 symmetry (Wyckoff site 18e).  相似文献   

4.
Reaction of [{Cp(CO)3Mo}2SbCl] with S8 or Se8 leads to the formation of cluster compounds [{Cp(CO)2Mo}2ESbCl] (E = S, Se). [{Cp(CO)2Mo}2SSbCl] crystallizes monoclinic, space group P21/n with a = 812.28(3), b = 855.65(4), c = 2441.01(9) pm and β = 90.149(3)°; [{Cp(CO)2Mo}2SeSbCl] · CH2Cl2 crystallizes triclinic, space group P$\bar{1}$ with a = 828.82(9), b = 1002.8(1), c = 1340.0(2) and α = 109.24(1), β = 100.87(1), γ = 96.81(1)°. For both compounds X‐ray crystal structure analysis reveals tetrahedral Mo2SbE cluster cores with Sb–E bond lengths of 256.8(1) pm (E = S) and 265.3(1) (E = Se). According to the 18 electron rule the [{Cp(CO)2Mo}2ESbCl] clusters can be regarded as complexes of the 4 electron donator ESbCl that is coordinated “side‐on” to a {Cp(CO)2Mo}2 fragment.  相似文献   

5.
The asymmetric total synthesis of murisolin, (15R, 16R, 19R, 20S)‐murisolin A, and (15R, 16R, 19S, 20S)‐16,19‐cis‐murisolin was performed by using an epoxy alcohol as a versatile chiral building block for synthesizing the stereoisomers of mono‐THF annonaceous acetogenins. The inhibitory activity of these murisolin compounds was examined with bovine heart mitochondrial complex I, and they showed almost the same activity.  相似文献   

6.
以手性四氢吡咯片段3a和3b为起始原料, 采用汇聚式合成策略, 完成氮杂Solamin类似物(threo-trans-erythro)的两个对应的光学异构体2a(15S,16S, 19S,20R, 34S)和2b(15R,16R,19R,20S, 34S)的不对称合成. 化合物的结构以及四氢吡咯片段的立体构型均通过NMR波谱解析的方法得到确证. 这两个非对映异构体具有相近的体外抗肿瘤活性.  相似文献   

7.
Multinuclear solid‐state NMR studies of Cp*2Sc−R (Cp*=pentamethylcyclopentadienyl; R=Me, Ph, Et) and DFT calculations show that the Sc−Et complex contains a β‐CH agostic interaction. The static central transition 45Sc NMR spectra show that the quadrupolar coupling constants (Cq) follow the trend of Ph≈Me>Et, indicating that the Sc−R bond is different in Cp*2Sc−Et compared to the methyl and phenyl complexes. Analysis of the chemical shift tensor (CST) shows that the deshielding experienced by Cβ in Sc−CH2CH3 is related to coupling between the filled σC‐C orbital and the vacant orbital.  相似文献   

8.
Multinuclear solid‐state NMR studies of Cp*2Sc?R (Cp*=pentamethylcyclopentadienyl; R=Me, Ph, Et) and DFT calculations show that the Sc?Et complex contains a β‐CH agostic interaction. The static central transition 45Sc NMR spectra show that the quadrupolar coupling constants (Cq) follow the trend of Ph≈Me>Et, indicating that the Sc?R bond is different in Cp*2Sc?Et compared to the methyl and phenyl complexes. Analysis of the chemical shift tensor (CST) shows that the deshielding experienced by Cβ in Sc?CH2CH3 is related to coupling between the filled σC‐C orbital and the vacant orbital.  相似文献   

9.
Simple Preparation Methods of the Only Known Perthiometallate [(S2)2(Mo)S2)2 Mo(S2)2]2? · On the Moiety {Mo2(S2)2}6+ Different aspects of the preparation of the only known perthiometallate [(S2)2Mo(S2)2Mo(S2)2]2? (a compound with the unusual coordination number (9) have been discussed. Simple preparation methods could be developed. A discussion of the properties of the stabilising central moiety {Mo(S2)2}6+ containing a metal-metal bond follows.  相似文献   

10.
Two novel porous three‐dimensional (3D) quaternary thioantimonates(III) ACuSb2S4 (A=Rb, Cs) were successfully synthesized by employing the neutral surfactant PEG‐400 (PEG=polyethyleneglycol) as reaction media, these are significantly different from the known quaternary A?Cu?Sb?S thioantimonates(III) with two‐dimensional (2D) crystal structures. This is the first time that crystalline quaternary chalcogenides have been prepared in surfactant media. Both experimental and theoretical studies confirm they are semiconductors with narrow band gaps. Our results demonstrated that the surfactant‐thermal strategy could offer a new opportunity to explore novel chalcogenides with diverse crystal structures and interesting physicochemical properties.  相似文献   

11.
The title phosphine oxide–phosphine, 0.43C17H16NOP·0.57C17H16NP, (I)/(II), was obtained as a 0.861 (6):1.139 (6) cocrystallized mixture. Hydrogen bonding between the two constituents leads to the formation of 2:2 solid‐state assemblies. Instead of forming the expected simple N,P‐chelated system via loss of the N‐bound H atom, reaction of 2‐(diphenylphosphinomethyl)pyrrole, (II), with TiCl4 leads to the formation of the title titanium(IV) complex, [TiCl4(C17H16NP)], (IV), containing a rearranged neutral ligand in which the N‐bound H atom moves to one of the pyrrole C atoms, giving a partially unsaturated ring.  相似文献   

12.
The crystal structure of Rb5Mo27Se31, penta­rubidium hepta­cosa­molybdenum hentria­conta­selenium, consists of a mixture of Mo12Se14Se6 and Mo15Se17Se6 cluster units in a 1:1 ratio. Both types of cluster are interconnected through inter‐unit Mo—Se bonds. Rb+ cations occupy large voids between the different cluster units.  相似文献   

13.
A several novel 1,3,4‐oxadiazinan‐2‐thiones have been synthesized by the cyclization of β‐hydrazino‐alcohols with either carbon disulfide or 1,1′‐thiocarbonyldiimidazole (TCDI).  相似文献   

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15.
The dimeric condensation product of lactic acid, namely (S,S)‐2‐[(2‐hydroxypropanoyl)oxy]propanoic acid, C6H10O5, (I), crystallizes with two independent molecules in the asymmetric unit, which both have an essentially planar backbone. The trimeric condensation product, namely (S,S,S)‐3‐hydroxybut‐3‐en‐2‐yl 2‐[(2‐hydroxypropanoyl)oxy]propanoate, C9H14O7, (II), has one molecule in the asymmetric unit and consists of two essentially planar parts, with the central C—O bond in a gauche conformation. Both molecules of the dimer are involved in intermolecular hydrogen bonds, forming chains with a C(8) graph set. These chains are connected by D(2) hydrogen bonds to form a two‐dimensional layer. The trimer forms hydrogen‐bonded C(10) and C22(6) chains, which together result in a two‐dimensional motif. The Hooft method [Hooft, Straver & Spek (2008). J. Appl. Cryst. 41 , 96–103] was successfully applied to the determination of the absolute structure of (I).  相似文献   

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The crystal structures of a pair of diastereomeric 1:2 salts of (R)‐ and (S)‐2‐methylpiperazine with (2S,3S)‐tartaric acid, namely (R)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (I), and (S)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (II), both C5H14N22+·2C4H5O6·H2O, each reveal the formation of well‐defined head‐to‐tail‐connected hydrogen tartrate chains; these chains are linked into a two‐dimensional sheet via intermolecular hydrogen bonds involving hydroxy groups and water molecules, resulting in a layer structure. The (R)‐2‐methylpiperazinediium ions lie between the hydrogen tartrate layers in the most stable equatorial conformation in (I), whereas in (II), these ions are in an unstable axial position inside the more interconnected layers and form a larger number of intermolecular hydrogen bonds than are observed in (I).  相似文献   

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