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1.
Towards Polysulfuric Acids: The Hydrogentrisulfate Anion [HS3O10]− in A[HS3O10] (A=Na,K, Rb) 下载免费PDF全文
Lisa Verena Schindler Prof. Dr. Thorsten Klüner Prof. Dr. Mathias S. Wickleder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(39):13865-13870
The reaction of Na2SO4 and K2SO4 with fuming sulfuric acid (65 % SO3) yielded colorless extremely sensitive crystals of Na[HS3O10] (monoclinic; P21/n (No. 14); Z=4; a=707.36(2), b=1378.56(4), c=848.10(3) pm; β=94.817(1)°; V=824.09(4) ? 106 pm3) and K[HS3O10] (orthorhombic; Pccn (No. 56); Z=4; a=1057.16(3), b=807.81(2), c=897.57(2) pm; V=766.51(3) ? 106 pm3). The analogous rubidium compound Rb[HS3O10] (orthorhombic; Pnma (No. 62); Z=4; a=891.43(3), b=1095.34(4), c=839.37(3) pm; V=819.58(5) ? 106 pm3) originates from the reaction of Rb2CO3 and SO3. All of the different structures contain the hitherto unknown anion [HS3O10]? and are stamped by strong hydrogen bonds linking the anions either to dimers or chains. Theoretical investigations by DFT methods give further insight in the structural characteristics of [HS3O10]?. The preparation of the [HS3O10]? anion can be seen as an important milestone on our way to the still elusive polysulfuric acids. 相似文献
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Julia Leitl Dr. Andrew R. Jupp Dr. Evi R. M. Habraken Verena Streitferdt Dr. Peter Coburger Dr. Daniel J. Scott Prof. Dr. Ruth M. Gschwind Prof. Dr. Christian Müller Dr. J. Chris Slootweg Prof. Dr. Robert Wolf 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(35):7788-7800
Salt metathesis of 1-methyl-2,4,6-triphenylphosphacyclohexadienyl lithium and chlorobis(pentafluorophenyl)borane affords a 1-phospha-7-bora-norbornadiene derivative 2 . The C≡N triple bonds of nitriles insert into the P−B bond of 2 with concomitant C−B bond cleavage, whereas the C≡C bonds of phenylacetylenes react with 2 to form λ4-phosphabarrelenes. Even though 2 must formally be regarded as a classical Lewis adduct, the C≡N and C≡C activation processes observed (and the mild conditions under which they occur) are reminiscent of the reactivity of frustrated Lewis pairs. Indeed, NMR and computational studies give insight into the mechanism of the reactions and reveal the labile nature of the phosphorus–boron bond in 2 , which is also suggested by detailed NMR spectroscopic studies on this compound. Nitrile insertion is thus preceded by ring opening of the bicycle of 2 through P−B bond splitting with a low energy barrier. By contrast, the reaction with alkynes involves formation of a reactive zwitterionic methylphosphininium borate intermediate, which readily undergoes alkyne 1,4-addition. 相似文献
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Various substituted dibenzo[b,f][1,4]oxazepines underwent an enantioselective alkylation with Et2Zn catalyzed by a (R)-VAPOL-Zn(II) complex. The corresponding chiral 11-ethyl-10,11-dihydrodibenzo[b,f][1,4]oxazepine derivatives were obtained with good yields and moderate enantioselectivities. This represents the first example of enantioselective addition of Et2Zn to cyclic aldimines. 相似文献
5.
Christoph Peschel Stefan van Wickeren Yves Preibisch Verena Naber Denis Werner Lars Frankenstein Dr. Fabian Horsthemke Prof. Dr. Urs Peuker Prof. Dr. Martin Winter Dr. Sascha Nowak 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(22):e202200485
Herein we report on an analytical study of dry-shredded lithium-ion battery (LIB) materials with unknown composition. Samples from an industrial recycling process were analyzed concerning the elemental composition and (organic) compound speciation. Deep understanding of the base material for LIB recycling was obtained by identification and analysis of transition metal stoichiometry, current collector metals, base electrolyte and electrolyte additive residues, aging marker molecules and polymer binder fingerprints. For reversed engineering purposes, the main electrode and electrolyte chemistries were traced back to pristine materials. Furthermore, possible lifetime application and accompanied aging was evaluated based on target analysis on characteristic molecules described in literature. With this, the reported analytics provided precious information for value estimation of the undefined spent batteries and enabled tailored recycling process deliberations. The comprehensive feedstock characterization shown in this work paves the way for targeted process control in LIB recycling processes. 相似文献
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Verena Bögelein Frank Duzaar Leah Schätzler Christoph Scheven 《Journal of Differential Equations》2019,266(11):7709-7748
We establish that solutions to the Cauchy–Dirichlet problem for functionals of linear growth can be obtained as limits of solutions to flows with p-growth in the limit . The result can be interpreted on the one hand as a stability result. On the other hand it provides an existence result for general flows with linear growth. 相似文献
8.
Unusual Bonding and Properties in Main Group Element Chemistry: Rational Synthesis,Characterization, and Experimental Electron Density Determination of Mixed‐Valent Tetraphosphetes 下载免费PDF全文
Verena Breuers Prof. Dr. Christian W. Lehmann Prof. Dr. Walter Frank 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(12):4596-4606
Five dispirocyclic λ3,λ5‐tetraphosphetes [{R2Si(NR1)(NR2)P2}2] (R1 = R2 and R1 ≠ R2) are easily prepared in almost quantitative yields via photolysis of the respective bis(trimethylsilyl)phosphanyldiazaphosphasiletidines with intense visible light. These deep‐yellow low‐coordinate phosphorus compounds can be considered as the first higher congeners of the well‐known cyclodiphosphazenes. The tetraphosphetes are remarkably stable in air and show unexpected molecular properties related to the unique bonding situation of the central four‐π‐electron four‐membered phosphorus ring. The extent of rhombic distortion of the central P4 ring is remarkable due to an unusually acute angle at the σ2‐phosphorus atoms. All of the P?P bonds are approximately equal in length. The distances are in the middle of the range given by phosphorus single and double bonds. The anisotropic absorption of visible light that can easily be observed in the case of the yellow/colorless dichroic crystals of [{Me2Si(NtBu)(NtBu)P2}2] and the exceptional 31P NMR chemical shift of the σ2‐phosphorus atoms are the most remarkable features of the λ3,λ5‐tetraphosphetes. In the case of [{Me2Si(NtBu)(NtBu)P2}2], the Hansen–Coppens multipole model is applied to extract the electron density from high‐resolution X‐ray diffraction data obtained at 100 K. Static deformation density and topological analysis reveal a unique bonding situation in the central unsaturated P4 fragment characterized by polar σ‐bonding, pronounced out‐of‐ring non‐bonding lone pair density on the σ2‐phosphorus atoms, and an additional non‐classical three‐center back‐bonding contribution. 相似文献
9.
Frontispiece: Unusual Bonding and Properties in Main Group Element Chemistry: Rational Synthesis,Characterization, and Experimental Electron Density Determination of Mixed‐Valent Tetraphosphetes 下载免费PDF全文
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