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91.
Elias AJ Twamley B Haist R Oberhammer H Henkel G Krebs B Lork E Mews R Shreeve JM 《Journal of the American Chemical Society》2001,123(42):10299-10303
The results obtained in a comprehensive experimental study on the redetermination of the structure of N(4)P(4)F(8) with single-crystal X-ray diffraction, gas electron diffraction (GED), and differential scanning calorimetry (DSC) establish clearly that, in contrast to the previous report, the eight-membered heterocycle is not planar. Above the phase transition temperature of -74 degrees C, the ring appears pseudoplanar. However, the N(4)P(4) ring is disordered and is puckered above the phase transition when the disorder is modeled correctly. Below the phase transition the ring clearly resembles that of the saddle (K form) of N(4)P(4)Cl(8). The unit cell of the low-temperature phase is derived from that of the higher temperature phase by doubling the c-axis and removing one-half of the symmetry elements. Full structure optimizations were performed at the HF/6-31G and B3LYP/6-31G levels and fully support the experimental diffraction data. 相似文献
92.
93.
Enno LorkRüdiger Mews Makhmut M. ShakirovPaul G. Watson Andrey V. Zibarev 《Journal of fluorine chemistry》2002,115(2):165-168
The first AlkNSNHetF sulfur diimide 6 (Alk=adamant-1-yl, HetF=2,3,5,6-tetrafluoropyrid-4-yl) was prepared by trapping of the corresponding alkylthiazylamide [AlkNSN]−3 with pentafluoropyridine, followed by X-ray structural characterization. For 6, the Z,E configuration was found. From the reaction of 3 with octafluoronaphthalene, hexafluorinated naphthothiadiazole 7 was isolated along with the parent AlkNH2. 相似文献
94.
Makarov AY Irtegova IG Vasilieva NV Bagryanskaya IY Borrmann T Gatilov YV Lork E Mews R Stohrer WD Zibarev AV 《Inorganic chemistry》2005,44(20):7194-7199
[1,2,5]Thiadiazolo[3,4-c][1,2,5]thiadiazole (1) is synthesized in 62% yield by fluoride ion-induced condensation of 3,4-difluoro-1,2,5-thiadiazole with (Me(3)SiN=)(2)S. The reversible electrochemical reduction of 1 leads to the long-lived [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazolidyl radical anion (2) and further to the dianion (3). The radical anion 2 is also obtained by the chemical reduction of the precursor 1 with t-BuOK in MeCN. The radical anion 2 is characterized by ESR spectroscopy in solution and in the crystalline state. The stable salts [K(18-crown-6)][2] and [K(18-crown-6)][2].MeCN (8 and 9, respectively) are isolated from the spontaneous decomposition of the [K(18-crown-6)][PhXNSN] (6, X = S; 7, X = Se) salts in MeCN solution followed by XRD characterization. The radical anion 2 acts as a bridging ligand in 8 and as chelating ligand in 9. The structural changes observed by XRD in going from 1 to 2 are explained by means of DFT/(U)B3LYP/6-311+G calculations. 相似文献
95.
Kingston M Chen SJ Lork E Mews R 《Dalton transactions (Cambridge, England : 2003)》2004,(9):1400-1404
The synthesis of TAS+ C3N3F4- (1) (TAS+ = (Me2N)3S+) and the reactions of 1 with Me3SiOSiMe3 and Me3SiCF3 to give TAS+ C3N3F2O- (2) and TAS+[(NCF)(NCCF3)(NC(CF3)(2)]- (4) are reported. An isomer of 4, TAS+[(NCCF3)2(NCFCF3)]-, compound 6, was obtained by fluoride ion addition to (CF3CN)3. From the reactions with Me3SiNMe2 neutral fluoroamino triazines C3N3Fn(NMe2)(n-1) (n = 1, 2) were isolated. Possible reaction pathways are discussed, the X-ray structures of 1, 2, 4 and 6 were determined. 相似文献
96.
Sascha Hoffmann Eugen Justus Michal Ratajski Enno Lork Detlef Gabel 《Journal of organometallic chemistry》2005,690(11):2757-2760
The reaction of B12H11NH3(1−) with carbodiimides can form guanidinium salts containing the boron cluster. Depending on the side chains of the carbodiimide, these derivatives of the B12H12(2−) cluster can be uncharged or can carry an overall positive or negative charge. This reaction allows the preparation of derivatives with aliphatic side chains, in contrast to the acylation reaction of and the formation of Schiff bases, both of which are successful only with aromatic acid chlorides or aromatic, respectively, α,β-unsaturated aldehydes. The acylation of with benzoyl chloride gives an N-protonated form of an imidoacid, carrying a single overall charge. 相似文献
97.
We study the influence of coupling strength and network topology on synchronization behavior in pulse-coupled networks of bursting Hindmarsh-Rose neurons. Surprisingly, we find that the stability of the completely synchronous state in such networks only depends on the number of signals each neuron receives, independent of all other details of the network topology. This is in contrast with linearly coupled bursting neurons where complete synchrony strongly depends on the network structure and number of cells. Through analysis and numerics, we show that the onset of synchrony in a network with any coupling topology admitting complete synchronization is ensured by one single condition. 相似文献
98.
Dr. Martin Hejda Daniel Duvinage Enno Lork Prof. Dr. Antonín Lyčka Prof. Dr. Zdeněk Černošek Dr. Jan Macháček Dr. Sergey Makarov Prof. Dr. Sergey Ketkov Dr. Stefan Mebs Prof. Dr. Libor Dostál Prof. Dr. Jens Beckmann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(59):14577-14581
The aryltellurenyl cation [2-(tBuNCH)C6H4Te]+, a Lewis super acid, and the weakly coordinating carborane anion [CB11H12]−, an extremely weak Brønsted acid (pKa=131.0 in MeCN), form an isolable ion pair complex [2-(tBuNCH)C6H4Te][CB11H12], in which the Brønsted acidity (pKa 7.4 in MeCN) of the formally hydridic B−H bonds is dramatically increased by more than 120 orders of magnitude. The electrophilic activation of B−H bonds in the carborane moiety gives rise to a proton transfer from boron to nitrogen at slightly elevated temperatures, as rationalized by the isolation of a mixture of the zwitterionic isomers 12- and 7-[2-(tBuN{H}CH)C6H4Te(CB11H11)] in ratios ranging from 62 : 38 to 80 : 20. 相似文献
99.
100.
Six adducts of B(C6F5)3 and archetypical alcoholates and carboxylates, were prepared and isolated as crystalline sodium crown ether salts, [Na(15‐crown‐5)][CH3O · B(C6F5)3] ( 1 ), [Na(15‐crown‐5)][CH3CH2O · B(C6F5)3] ( 2 ), [Na(15‐crown‐5)][HCO2 · B(C6F5)3] ( 3 ), [Na(15‐crown‐5)][(H3CCO2 · B(C6F5)3] ( 4 ), [Na(15‐crown‐5)][(F3CCO2 · B(C6F5)3] ( 5 ), and [Na2(15‐crown‐5)3][C2O4 · 2 B(C6F5)3] ( 6 ). All compounds were fully characterized by multinuclear NMR‐ and IR spectroscopy, ESI MS spectrometry, and X‐ray crystallography. 相似文献