Polysulfonylamine. CLXVI [1] Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 15 [1] Die isotypen Kristallstrukturen von Ammonium‐ und Caesium‐dimesylamid: Kristallographische Kongruenz zwischen Wasserstoffbrücken N—H···O/N und Metall‐Ligand‐Bindungen Cs—O/N

Polysulfonylamines. CLXVI. Crystal Structures of Metal Di(methanesulfonyl)amides. 15. The Isotypic Crystal Structures of Ammonium and Cesium Dimesylamide: Crystallographic Congruency of Hydrogen Bonds N—H···O/N and Metal‐Ligand Interactions Cs—O/N The ammonium salt NH₄[N(SO₂CH₃)₂] and its previously reported cesium analogue Cs[N(SO₂CH₃)₂] are isostructural (monoclinic, space group P2₁/n, Z = 4, V at —140 °C: 0.761 and 0.832 nm³ respectively). The cesium ion adopts an irregular (O₆N)‐heptacoordination by forming close contacts to one (O, N)‐chelating, one (O, O)‐chelating and three κ¹O‐bonding anions, whereas in the ammonium‐based structure each of the seven Cs—O/N interactions is perfectly mimicked by an N—H···O/N hydrogen‐bond component. To this effect, three N—H donors are engaged in asymmetric three‐centre bonds, the fourth in a moderately strong and approximately linear two‐centre bond. The crystal packings consist of anion monolayers that intercalate planar zigzag rows of cations propagating around symmetry centres (Cs···Cs alternatingly 422.5 and 487.5 pm, Cs···Cs···Cs 135.7°; N···N alternatingly 397.4 and 474.1 pm, N···N···N 136.1°). Each cation row is surrounded by and bonded to four translation‐generated anion stacks, and each anion stack connects two cation rows. The net effect is that the packings display congruent three‐dimensional networks of metal‐ligand bonds or hydrogen bonds, respectively. Moreover, close C—H···O/N interanion contacts consistent with weak hydrogen bonding are observed in both structures.     

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.     

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.     

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.     

Characterization of chlorins within a natural chlorin mixture using electrospray/ion trap mass spectrometry

Chlorins in a sedimentary mixture were characterized, without prior isolation of individual components, using electrospray ionization combined with ion trap mass spectrometry. Collision-induced dissociation in the atmospheric sampling interface and multi-step mass spectrometry (i.e. MSⁿ where n ? 2) were used in order to obtain structural information about the macrocycle. Fragmentation pathways are proposed for different macrocycle types based on data from model chlorins. Three unknown chlorins (RMM = 888, 844 and 790) are assigned as having bacteriochlorophyll macrocycle types esterifled to unusual side-chains (i.e. dihydrophytol for the unknown with a bacteriopheophorbide a structure, phytol and an alcohol with a molecular mass of 242 u for the two unknowns with a proposed bacteriopyropheophorbide d structure).     

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.     

A green,efficient and recyclable poly(4-vinylpyridine)-supported copper iodide catalyst for the synthesis of coumarin derivatives under solvent-free conditions

Poly(4-vinylpyridine)-supported copper iodide is reported as a green, efficient and recyclable catalyst for the synthesis of coumarin derivatives by the Pechmann reaction under solvent-free conditions. This catalyst can be recovered by simple filtration and recycled up to eight consecutive runs without any loss of their efficiency.     

Towards a new class of ferroelectric liquid crystal molecules for nonlinear optical applications

The synthesis of a new molecule specifically designed to exhibit both ferroelectric and nonlinear optical properties is presented. This molecule possesses an optically active phenyl sulphinic group, which introduces a dipole moment directly linked to the chromophore group, with a nitro group in the meta -position. The rest of the molecule comprises a tolane and a benzoate group. Such a structure results in an enantiotropic smectic C*-smectic A phase sequence in its polymorphism. A first measurement of the spontaneous polarization shows a high value. The polymorphism of the racemic homologous molecule possessing the nitro group in the ortho-position is also presented, and also shows the smectic C-smectic A phase sequence.