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1.
The prominent features in the molecular structure of the title compound (alternative name: 2‐diethyl­carbamoyl‐1,1,3,3‐tetraoxo‐1,3,2‐benzodi­thia­zole), C11H14N2O5S2, arise in the urea moiety S2N—C(O)—N′C2: the sum of the angles at N is 332.3 (1)°, the N—C(O)—N′C2 unit is planar, and distances N—C(O) = 1.494 (3) Å, N′—C(O) = 1.325 (2) Å and C—O = 1.215 (2) Å. The mol­ecules are associated via five C—H?O hydrogen bonds to form layers parallel to the yz plane. This compound and its di­methyl homologue, which were synthesized by treating the silver salt of o‐benzene­disulfon­imide with carbamoyl chlorides, are prone to rapid hydro­lysis at the weak N—C(O) bond. For both mol­ecules, the rotational barrier about the partial N′—C(O) double bond is ca 50 kJ mol?1 at 250 K (from dynamic 1H NMR experiments).  相似文献   

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Ten years from Glenn T. Seaborg’s death we remember his achievements; his teaching about the importance of basic research is as timely as ever.  相似文献   

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The structure changes and the degree of reduction of U3O8 after mechanoactivation in agate and stainless steel vessels in different media are studied. Clearly expressed reduction of U(IV, VI) oxide, accompanied by oxygen release as a result of mechanochemical activation is observed. The highest degree of reduction is reached when mechanoactivation is performed in suspension with nonpolar organic solvents. The presence of acetaldehyde as a reducing agent did not cause valuable increase of the reduction process. Quantitative evaluation of the mechanochemically induced changes in the crystal structure of U3O8 is done. Decrease of the crystallite sizes of both the U3O8 and the reduced form, provoked by the mechanochemical treatment is observed for all the samples. No other uranium-contained compounds, formed during the mechanoactivation in the different media and mixtures were found.  相似文献   

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We present an efficient numerical integration scheme (TWOCENT) to be used in the context of automatized parameterization of the density‐functional tight‐binding (DFTB) method. The accuracy of the integration process is assessed and its range of applicability is discussed. The functionality of the developed code is tested by reproducing the electronic portion of the existing mio parameter sets and by reproducing a series of reference DFT band structures of elemental solids.  相似文献   

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A synthesis of the novel C10H16 hydrocarbon 1,7-trimethylenenorbornane ( 13 ), one of the 19 members of the adamantane family, is described.  相似文献   

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The novel androstane‐type steroidal glycoside 1 was isolated from the roots of Asparagus curillus Buch .‐Ham . ex Roxb . Its structure was elucidated as (2α,3β,5α,17β)‐17‐(1‐methoxyethoxy)‐17‐methylandrostane‐2,3‐diol 3‐(β‐D ‐digitoxopyranoside) by means of chemical and advanced spectral analysis.  相似文献   

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