Reactivity of Lewis acids towards nitriles; crystal structure and electron deformation density of C2N2·SbF5and photoelectron spectrum of AsF5

1992 ◽  
pp. 537-543 ◽  
Author(s):  
Inis C. Tornieporth-Oetting ◽  
Thomas M. Klapötke ◽  
T. Stanley Cameron ◽  
Jussi Valkonen ◽  
Paul Rademacher ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Lewis Acids ◽  
Photoelectron Spectrum ◽  
Deformation Density

The Syntheses and Crystal-Structures of Decahydro-5,14:6,13:7,12-Trimethanopentacene and Decahydro-5,14-7,12-Dimethanopentacene: Two Useful Molecules for Investigating Laticyclic Hyperconjugation

1986 ◽  
Vol 39 (10) ◽  
pp. 1587 ◽  
Author(s):  
DC Craig ◽  
MN Paddonrow ◽  
HK Patney
Keyword(s):  
Crystal Structure ◽  
Ab Initio Calculations ◽  
Crystal Structures ◽  
Reductive Dechlorination ◽  
Photoelectron Spectrum ◽  
Alder Reaction ◽  
Diels Alder ◽  
Basis Set ◽  
Orbital Interactions ◽  
Diels Alder Reaction

The syntheses of decahydro-5,14:6,13:7,12-trimethanopentacene and decahydro-5,14:7,12-dimethanopentacene are described (see Schemes 1 and 2 respectively). Diels -Alder reaction of diene (10) with two equivalents of tetrachlorothiophen 1,1-dioxide (11) gave the adduct (12), which was aromatized to (13) through treatment with base. Reductive dechlorination (Na/ PriOH ) of (13) gave (6). A similar set of reactions performed on (17), itself prepared from cyclohexa-1,4-diene and two equivalents of hexachlorocyclopentadiene (15), gave (7). The crystal structures of (6) and (7) were determined. An interesting feature of the structure of (7) is the slight endo pyramidalization (by c. 3°) of the trigonal carbon atoms C 4a, C 7a, C 11a and C 14a. Model ab initio calculations (STO-3G basis set) on complexes (27) and (28), whose geometries were culled from the crystal structure of (6), indicate that significant laticyclic hyperconjugative interactions (c. 0.3 eV ) are mainly responsible for causing the observed splitting between the πs+πs and πs-πs levels in the photoelectron spectrum of (6). Orbital interactions through the pair of six connecting sigma bonds (OIT-6-B) in (6) have a negligible effect (c. 0.08 eV ) on these levels. In agreement with prediction, laticyclic hyperconjugation does not affect the πa+πa and πa-πa levels.

Singly Charged λ6Si-Silicate Anions with an SiF5C Skeleton: Syntheses and Crystal Structure Analyses of the Ionic Hexacoordinate Silicon Compounds [Me3NH][F5SiCH2NMe2H]·H2O and [Me3NH][F5SiCH2NMe2H]·H2O

2000 ◽  
Vol 55 (1) ◽  
pp. 60-64
Author(s):  
Melanie Pülm ◽  
Joachim Becht ◽  
Reinhold Tacke
Keyword(s):  
Crystal Structure ◽  
Lewis Acids ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
Silicon Compounds ◽  
X Ray ◽  
Distorted Octahedra ◽  
Singly Charged ◽  
Crystalline Hydrates

The zwitterionic λ5Si-tetrafluorosilicates F4SiCH2NMe2H (1) and F4SiCH2NMe3 (2) behave as Lewis acids and react with [Me3NH]F (molar ratio 1:1) in aqueous solution to yield the ionic λ6Si-pentafluorosilicates [Me3NH][F5SiCH2NMe2H] (3) and [Me3NH][F5SiCH2NMe3] (4), respectively. These hexacoordinate silicon compounds contain singly charged λ6Si-silicate anions ([F5SiCH2NMe2H]- , [F5SiCH2NMe3]- ) with an SiF5C skeleton. Compounds 3 and 4 were isolated as the crystalline hydrates 3·H2O (yield 80%) and 4·H2O (yield 82%) which were structurally characterized by single-crystal X-ray diffraction. The Si-coordination polyhedra in the crystals of 3·H2O and 4·H2O are slightly distorted octahedra

Multidentate Lewis acids. Crystal structure of the 1:1 complex of dichloro(1,2-phenylene)dimercury with dimethylformamide

1987 ◽  
Vol 6 (1) ◽  
pp. 153-156 ◽  
Author(s):  
Andre L. Beauchamp ◽  
Marc J. Olivier ◽  
James D. Wuest ◽  
Boulos. Zacharie
Keyword(s):  
Crystal Structure ◽  
Lewis Acids

Copolymerisation of Pt–carbonyl clusters with Lewis acids: synthesis and crystal structure of the molecular {Cd2Cl4[Pt9(CO)18]2−}∞1-D polymer

2006 ◽  
pp. 2135-2137 ◽  
Author(s):  
Cristina Femoni ◽  
Francesco Kaswalder ◽  
Maria Carmela Iapalucci ◽  
Giuliano Longoni ◽  
Stefano Zacchini
Keyword(s):  
Crystal Structure ◽  
Lewis Acids ◽  
Carbonyl Clusters ◽  
Synthesis And Crystal Structure ◽  
Pt Carbonyl Clusters

Orthoamide, LXVII [1]. Bis(diformylamino)methan – ein neues leistungsfähiges Formylierungsmittel für aromatische Verbindungen / Orthoamides, LXVII [1]. Bis(diformylamino)methane – a New Efficient Formylating Reagent for Aromatic Compounds

2008 ◽  
Vol 63 (4) ◽  
pp. 395-406 ◽  
Author(s):  
Willi Kantlehner ◽  
Ernst Anders ◽  
Jochen Mezger ◽  
Edmont V. Stoyanov ◽  
Ralf Kreß ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Lewis Acid ◽  
Structure Determination ◽  
Aromatic Compounds ◽  
Lewis Acids ◽  
Crystal Structure Determination ◽  
Pyridinium Chloride ◽  
Guanidinium Salt

AbstractFormaldehyde reacts with diformamide (10) to give N-(hydroxymethyl)diformamide (11), which upon treatment with thionylchloride yields N-(chlormethyl)diformamide (12) together with small amounts of oxydimethylenebis(diformamide) (13). Various diformylamine derivatives, such as diformylaminomethyl formiate (14), diformylaminomethylisothiocyanate (15) and the N-diformylaminomethylated guanidinium salt 16, can be prepared from 12. Bis(diformylamino) methane (7) can be obtained by the reaction of sodium diformamide (8) with either 1-(chloromethyl)pyridinium chloride (9) or N-(chloromethyl)diformamide (12) in acetonitrile. The action of tris(chloromethyl) amine (18) on sodium diformamide (8) affords tris(diformylaminomethyl)amine (19). The constitution of the compounds 7, 11 and 19 was confirmed by crystal structure determination. The nature of the products from the reactions of aromatic compounds with 12 depends on the Lewis acid which is used as activator. Thus the N-benzylformamides 20a, b can be obtained from toluene and mesitylene and 12/BF3-ether, whereas 1,2,4-trimethoxybenzene is formylated by 12/AlCl3 to give the aldehyde 22. Interestingly enough, a novel and efficient formylating reagent resulted from these investigations: bis(diformylamino)methane (7), which can be activated by Lewis acids, e. g. AlCl3. The scope of this procedure is comparable with that of the Olah-formylation method (formylfluoride/BF3).

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