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Anika Sabine Lindner Egor Geist Mimoza Gjikaj Andreas Schmidt 《Journal of heterocyclic chemistry》2014,51(2):423-431
Pyrrolo[2,1‐c][1,4]benzodiazepine‐5,11‐dione and its 7‐bromo derivative were alkylated at the N10 atom applying various methods. The resulting products were subjected to Suzuki–Miyaura reactions using a catalyst system consisting of Pd(Cl)2(PPh3)2 and sodium tert‐butanolate in toluene. Results of an X‐ray single crystal analysis are presented. 相似文献
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Colourless block‐shaped crystals of [(NH4)2(2.2.2‐cryptand)2][P2S8] ( 1 ) and [(NH4)2(18‐crown‐6)2][P2S8]·H2O ( 2 ) could be obtained by the reaction of an aqueous solution of ammonium hexathiohypodiphosphate, (NH4)4P2S6·2 H2O, with sulfur and 2.2.2‐cryptand or 18‐crown‐6. The crystal structures of both compounds have been determined by single‐crystal X‐Ray diffraction analysis. Compound 1 crystallizes in the monoclinic space group C2/c with a = 2032.7(2), b = 1243.6(2), c = 2244.6(2) pm, β = 98.64(1)°, and Z = 8, whereas compound 2 crystallizes also monoclinic in the space group P21/c with a = 2121.3(2), b = 865.5(1), c = 2345.4(2) pm, β = 91.96(1)°, and Z = 4. It could be established that the title compounds contain a new type of six‐membered [1,2‐P2S4] ring with P – P bond and three S – S linkages. The tetrahedral environment of each phosphorus is completed by a (formally) single and double bonded sulfur atom attached externally to the [1,2‐P2S4] ring. These terminal PS2 units are mesomerically stabilized according to their P – S distances. FT‐IR and FT‐Raman spectra of the title compounds are recorded and interpreted. 相似文献
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Schmidt A Habeck T Lindner AS Snovydovych B Namyslo JC Adam A Gjikaj M 《The Journal of organic chemistry》2007,72(6):2236-2239
Indazolium-3-amidates (X-ray analysis), readily available on trapping the N-heterocyclic carbene indazol-3-ylidene with isocyanates, underwent [3+2]-cycloadditions with activated triple bonds to spiro[indazole-3,3'-pyrroles]. A combination of NMR techniques such as heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear Overhauser enhancement spectroscopy (NOESY), and 1H/15N correlations were applied to elucidate the structures of the cycloadducts. 相似文献
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The reaction of silyl-substituted carbanion 1b with arene-1,2-dicarboxylates 6, 15 yields indenone derivatives 11, 16 in a domino process involving silyl C→O migration and elimination. However, in a competing pathway, the initial addition of 1b leads to lactone formation (8, 17). Substrates 26, 38 containing an ester group and a bromine substituent react with 1b under substitution of the halogen not allowing silyl migration. But desilylation with TBAF gives reactive carbanions providing benzo-annulated cycloalkanones 29, 40. 相似文献
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This work presents a follow-up research of our previously published work. Herein, the photocatalytic performance of a nanostructured CdZnO/NiCdO composite photoanode has been improved by intercalation of Cu catalyst atoms in the electron barrier layer of NiyCd1?yO surface by an ion exchange process. As a result, the photocurrent yield increased by 29 % at +1 V potential against Ag/AgCl. This phenomenon was tentatively attributed to the increased electron concentration and/or interaction of the Cu3d electrons with the mid-energy valence electrons. To the contrary, the introduction of Ag, Co, and Ni deteriorated the photocatalytic performance. The corrosion challenges were assessed during 50 cycles of voltammetry. The background of the degradation/photocorrosion was studied with SEM, EDX, and XPS analysis. To combat the photocorrosion, the photoanodes were coated with TiO2 protective nanolayers of different thickness. The results for the photocurrent stability at a constant potential of +1 V showed that 9 nm TiO2 coating improved the durability of the photoanode on account of a photocurrent decrease for about 50 %. XPS studies proved that the degradation/corrosion changes on the photoanode’s surface could be associated with an irreversible electrochemical oxidation of CdO into CdO2. 相似文献
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Preparation,Crystal Structure,Vibrational Spectra,and Thermal Behavior of Tl2H2P2O6 and Tl4P2O6 下载免费PDF全文
The new thallium(I) salts, Tl2H2P2O6 ( 1 ) and Tl4P2O6 ( 2 ), were prepared and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the monoclinic space group P21/c and compound 2 in the orthorhombic space group Pbca. Both structures feature channels occupied by the lone electron pairs of Tl+ cations. Furthermore, those are built up by discrete [H2P2O6]2– for compound 1 and [P2O6]4– units for 2 in staggered conformation for the P2O6 skeleton and the thallium cations. In Tl2H2P2O6 ( 1 ) the hydrogen atoms of the [H2P2O6]2– ion are in a “trans‐trans” conformation. The O ··· H–O hydrogen bonds between the [H2P2O6]2– groups consolidate the structure 1 into a three‐dimensional network. FT‐IR/FIR and FT‐Raman spectra of the crystalline title compounds were recorded and a complete assignment for the P2O64– modes is proposed. The phase purity of 1 was verified by powder diffraction measurements. 相似文献
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The new hexathiodiphosphate(IV) hydrates K4[P2S6] · 4 H2O ( 1 ), Rb4[P2S6] · 6 H2O ( 2 ), and Cs4[P2S6] · 6 H2O ( 3 ) were synthesized by soft chemistry reactions from aqueous solutions of Na4[P2S6] · 6 H2O and the corresponding heavy alkali‐metal hydroxides. Their crystal structures were determined by single crystal X‐ray diffraction. K4[P2S6] · 4 H2O ( 1 ) crystallizes in the monoclinic space group P 21/n with a = 803.7(1), b = 1129.2(1), c = 896.6(1) pm, β = 94.09(1)°, Z = 2. Rb4[P2S6] · 6 H2O ( 2 ) crystallizes in the monoclinic space group P 21/c with a = 909.4(2), b = 1276.6(2), c = 914.9(2) pm, β = 114.34(2)°, Z = 2. Cs4[P2S6] · 6 H2O ( 3 ) crystallizes in the triclinic space group with a = 742.9(2), b = 929.8(2), c = 936.8(2) pm, α = 95.65(2), β = 112.87(2), γ = 112.77(2)°, Z = 1. The structures are built up by discrete [P2S6]4? anions in staggered conformation, the corresponding alkali‐metal cations and water molecules. O ··· S and O ··· O hydrogen bonds between the [P2S6]4? anions and the water molecules consolidate the structures into a three‐dimensional network. The different water‐content compositions result by the corresponding alkali‐metal coordination polyhedra and by the prefered number of water molecules in their coordination sphere, respectively. The FT‐Raman and FT‐IR/FIR spectra of the title compounds have been recorded and interpreted, especially with respect to the [P2S6]4? group. The thermogravimetric analysis showed that K4[P2S6] · 4 H2O converted to K4[P2S6] as it was heated at 100 °C. 相似文献
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1‐Butyl‐4‐methylpyridinium hexachloridotantalate(V), [BMPy][TaCl6] ( 1 ), tetrakis(1‐butyl‐4‐methylpyridinium) bis(hexachloridotantalate(V) (μ‐oxido)‐decachloridotantalate(V), [BMPy]4[(TaCl6)2(Ta2OCl10)] ( 2 ), and bis(1‐ethyl‐3‐methylimidazolium)‐(μ‐oxido)‐decachloridoditantalate(V), [EMIm]2[Ta2OCl10] ( 3 ) were synthesized and characterized by single‐crystal X‐ray diffraction and vibrational spectroscopy. Compounds 1 and 3 crystallize in the monoclinic space group P21/c (no. 14), whereas compound 2 crystallizes in the triclinic space group P (no. 2). All compounds are built up by the mentioned bulky organic cations and octahedral [TaCl6]– respective linear [Ta2OCl10]2– anions. Coulomb interactions are dominant between the ionic species. FT‐IR and FT‐Raman spectra were recorded and interpreted, especially with respect to the inorganic species [TaCl6]– (Oh) and [Ta2OCl10]2– (Ci symmetry, approximately D4h). The melting temperatures of compounds 1 – 3 are given. 相似文献
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Preparation,Crystal Structure and Vibrational Spectra of Ca2P2O6·2H2O and [Ca(H2O)3(H2P2O6)]·0.5(C12H24O6)·H2O 下载免费PDF全文
The calcium salts Ca2P2O6 · 2H2O ( 1 ) and [Ca(H2O)3(H2P2O6)] · 0.5(C12H24O6) · H2O ( 2 ) were prepared and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pbca and compound 2 in the monoclinic space group P21/n. The crystal structure of compound 1 consists of chains of edge‐sharing [CaO7] polyhedra linked by hypodiphosphate(IV) anions to form a three‐dimensional network. The crystal structure of compound 2 consists of alternated layers of crown ether and water molecules and respective ionic units. Within the layers of ionic units the Ca2+ cations are octahedrally coordinated by three monodentate dihydrogenhypodiphosphate(IV) anions and three water molecules. The IR/Raman spectra of the title compounds were recorded and interpreted, especially with respect to the [P2O6]4– and [H2P2O6]2– groups. The phase purity of 2 was verified by powder diffraction measurements. 相似文献