Lithium intercalation in polyacetylene

The coulometric titration curve for lithium intercalation in polyacetylene has been determined using poly(ethylene oxide) based solid electrolyte. The plateaus observed suggest the existence of stages, comparable to graphite. This interpretation seems also supported by the cyclic voltammetry scans on polyacetylene. Lithium intercalation appears as a very slow process with

estimated at ? 10^-13cm².s^-1.     

Etude par Spectrométrie de Masse du Di-O-isopropylidene-1,2;5,6-α-D-ribo-hexofurannosul-3-ose

The electron impact mass spectrum of 1, 2:5, 6-di-O-isopropylidene-α-D -ribo-hexofuranos-3-ulose has been studied. Fragmentation modes based upon deuterium and ¹⁸O labelling are proposed.     

Spectrographie de masse en série du bornane I: Bornanes monosubstitués

A study has been made of the fragmentation of 2- and 3-monosubstituted bornanes. Ketones, oximes, alcohols, amines and their N-methyl derivatives were examined. Different fragmentations were compared according to the 2- or 3-position of the substituents. The results show the importance of cleavage α to the substituent bearing the charge. The α bond cleaved is that bond directed to the carbon atom with the greater degree of substitution. These results allow one to differentiate, by mass spectroscopy, the 2- and the 3-positions in the bornane skeleton.     

Polysulfonylamine. LXXII [1]. Triphenylcarbenium- und Triphenylphosphonium-di(fluorsulfonyl)amid: Zwei Kristallstrukturen mit geordneten (FSO2)2N⊖-Lagen

Polysulfonyl Amines. LXXII. Triphenylcarbenium and Triphenylphosphonium Di(fluorosulfonyl)amides: Two Crystal Structures with Ordered (FSO₂)₂N^? Sites Treatment of HN(SO₂F)₂ in CH₂Cl₂ with Ph₃P, Ph₃PO or collidine (=B) affords the compounds Ph₃PH^⊕[(FSO₂)₂N]^? ( 3 ), Ph₃PO · HN(SO₂F)₂, and BH^⊕[(FSO₂)₂N]^? ( 7 ). The carbenium salt Ph₃C^⊕[(FSO₂)₂N]^? ( 5 ), obtained by metathesis of Ph₃CBr with [(C₆H₆)AgN(SO₂F)₂] in CH₂Cl₂, crystallizes from chloroform/petroleum ether as a monosolvate Ph₃C^⊕[(FSO₂)₂N]^? · CHCl₃ ( 6 ). In presence of a sterically hindered base, viz. collidine, 5 is a suitable reagent for the tritylation of molecules containing weakly activated H atoms (e. g.: MeCN → Ph₃CCH₂CN, acetone → tritylacetone; co-product: 7 ). The crystal structures of the ionic solids 3 (monoclinic, space group P2₁/n) and 6 (monoclinic, P2₁/c) were determined by X-ray diffraction at ?130°C; the structure refinements were not impaired by the notorious tendency of the (FSO₂)₂N moiety towards crystallographic disorder. As in the known structure of the tetraphenylarsonium salt, the anion of 3 and 6 adopts a staggered conformation of approximately C₂ symmetry (averages of all values: S? N? S 121.4°, N? S 156.2, S? O 141.6, S? F 156.6 pm). The crystal packing of 6 displays a three-centre C? H(…?O)₂ hydrogen bond between the CHCl₃ molecule and two oxygen atoms of a single anion, resulting in a six-membered ring [R₁²(6) pattern; H …? O 234 and 262 pm]. The crystal of 3 contains one-dimensional arrays of alternating cations and anions connected by a three-centre P? H(…?O)₂ bond [C(6) pattern; H …? O 237 and 254 pm]. The Ph₃C^⊕ cation of 6 is propeller-shaped, with three coplanar central bonds (mean C? C 144.5 pm) and interplanar angles of 52.7, 56.4 and 60.1° between the phenyl groups.     

Aziridines—XVI: Etude des conformations privilegiees cycle aromatique-petit cycle dans les C-aryl aziridines N-non-substituees

The preferred conformation of phenyl-2 aziridine involves the phenyl ring nearly bisecting the plane of the small ring (maximum conjugation). As the steric hindrance due to substituents on the aromatic ring is more substantial, the aromatic ring moves towards a perpendical plane. Good agreement between experimental (IR and NMR) and theoretical studies of the syn-anti configurational equilibrium of NH in these compounds is demonstrated. The analysis of the total electronic populations clarifies an understanding of the variation of the charge transfer small ring?aromatic cycle as a function of the aromatic nucleus.     

Neue Chlorsilyl- und Alkoxysilyl-alkyl-peroxide

The alkyl-chlorosilyl-peroxides1 and2, the alkoxysilylalkyl-peroxides3 to7 (Table 1) as well as the hitherto unknown chlorosilanes (n-PrO)Me ₂SiCl and (t-BuO)Me ₂SiCl were prepared, isolated and characterized by analytical and¹H-NMR data. Attempts to isolate the unstable peroxides (i-PrO)₃SiOOCMe ₃ and (Me ₃CO)Me ₂SiOOCMe ₂ Ph failed.     

Kristallstrukturen des freien protonierten Liganden HN(SO2)2C6H4 (= HZ) und des lamellaren Caesiumsalzes CsZ

Metal Salts of Benzene‐1,2‐di(sulfonyl)amine. 3. Crystal Structures of the Free Protonated Ligand HN(SO₂)₂C₆H₄ (= HZ) and the Lamellar Cesium Salt CsZ Benzene‐1,2‐di(sulfonyl)amine ( 1 ; HZ), known since 1921, is a very strong NH acid and readily reacts with aqueous CsCl to form crystalline CsZ ( 3 ). For both compounds, crystal structures were determined by X‐ray diffraction at –100 °C ( 1 : monoclinic, space group P2₁/n, Z = 4; 3 : orthorhombic, Cmcm, Z = 4). In 1 , the five‐membered 1,3,2‐dithiazole heterocycle possesses an envelope conformation, the N atom lying 29.4(2) pm outside the mean plane of the S–C–C–S moiety [S–N 167.06(15) and 167.53(15) pm, S–N–S 114.57(8)°]. In the crystal, HZ molecules are linked into chains by a conventional N–H…O hydrogen bond and further associated via four weak C–H…O bonds to form a three‐dimensional network. The conjugate Z^⊖ ion in the layered structure of the salt 3 displays crystallographic C_2v symmetry, leading to an ideally planar bicyclic framework [S–N 158.29(15) pm, S–N–S 116.53(17)°]. Each of the five electronegative atoms bridges two cations, Cs^⊕ attaining a tenfold coordination by forming bonds to two (O,N,O)‐chelating and four κ¹O‐monodentate ligands. The Cs–O/N interactions create a polar [CsN(SO₂)₂]_∞ lamella, which is lipophilically wrapped by parallel benzo rings protruding perpendicularly from its surfaces. In contrast to the previously reported lamellar metal di(arenesulfonyl)amides, the aromatic groups pertaining to adjacent layers of 3 are seen to be markedly interlocked.     

Etude des mécanismes de réarrangement dans la fragmentation des benzoyloxy-cyclopentànes par impact électronique

The fragmentation modes of 3-benzoyloxy-cyclopentene and of 4-benzoyloxy-cyclopentene have been studied on deuterium-labelled analogues. A mathematical model is proposed for the study of the rearrangement reactions which occur during the expulsion of H₂O and of \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CO}_2 {\rm H}^. $\end{document} from the molecular ion of 3-benzoyloxy-cyclopentene.