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Stoeckli-Evans, Helen
Nom
Stoeckli-Evans, Helen
Affiliation principale
Fonction
Professeur.e émérite
Email
helen.stoeckli-evans@unine.ch
Identifiants
Résultat de la recherche
Voici les éléments 1 - 10 sur 45
- PublicationMétadonnées seulement1,4-Bis(hex-yloxy)-2,5-diiodo-benzene(2010)
; ; - PublicationMétadonnées seulement1,4-Bis(hexyloxy)-2,5-diiodobenzene(2010)
; ; - PublicationAccès librePreparation of donor–acceptor substituted fluorostilbenes and crystal chemistry of fluorinated (E)-4-(4-halogeno-styryl)-benzonitriles(2009)
; Hulliger, JürgThe syntheses and crystal structures of a series of fluoro-substituted halogeno (Cl, Br, I)-cyano-stilbenes containing donor and acceptor groups (D-π-A) are reported. These molecules show a tendency to form antiparallel chain-like structures and herringbone packing, crystallising predominantly in a centric space group. However, second harmonic generation measurements bear evidence for orientational disorder leading to partial polar order below the ordinary X-ray structure determination limit. Some co-crystals are isostructural with their components. The non-fluoro as well as the halogeno-fluoro substituted components of co-crystals seem to impose their crystal structure on the complementary fluoro- or cyano–fluoro substituted components. Co-crystallization enhanced the deviation from centrosymmetry. - PublicationAccès libreAn efficient one-pot synthesis of strongly fluorescent (hetero)arenes polysubstituted with amino and cyano groups(2008)
; - PublicationAccès libreThree-dimensional bimetallic octacyanidometalates [MIV{(μ-CN)4MnII (H2O)2}2•4H2O]n (M = Nb, Mo, W): Synthesis, single-crystal X-ray diffraction and magnetism(2008)
; - PublicationMétadonnées seulementThe high stereoselectivity of the tandem sequence Diels-Alder reaction/Ireland-Claisen rearrangement starting from substituted O-(E)-buta-1,3-dienyl ketene acetals and cyclic dienophiles(2007)
; A new tandem reaction leads to bicyclic cyclohexene derivs., e. g. I, with complete control of the relative configuration of the four chiral centers formed. The high diastereoselectivity is the consequence of an endo-selective Diels-Alder reaction followed by an Ireland-Claisen rearrangement that proceeds via a boat-like transition state. [on SciFinder(R)] - PublicationAccès libreThe High Stereoselectivity of the Tandem Sequence Diels-Alder Reaction/Ireland-Claisen Rearrangement Starting from Substituted O-(E)-Buta-1,3-dienyl Ketene Acetals and Cyclic Dienophiles(2007)
; A new tandem reaction leads to bicyclic cyclohexene derivatives with complete control of the relative configuration of the four chiral centers formed. The high diastereoselectivity is the consequence of an endo-selective Diels-Alder reaction followed by an Ireland-Claisen rearrangement that proceeds via a boat-like transition state. - PublicationAccès libreSynthesis, crystal structures and spectra of Hg(II)-1,2-bis(diphenylphosphino)ethane monoxide complexes: Monomer and polymer formation(2007)
; Panchanatheswaran, KrishnaswamyThe reaction of mercury(II) halides with 1,2-bis(diphenylphosphino)ethane monoxide (dppeO) in 1:1 molar ratio yielded P,O-coordinated polymers having the empirical formula [HgX2 (dppeO)]n [X = Cl (1), Br (2), I (3)]. In contrast, the reaction between the same reactants in a 1:2 molar ratio yielded the P, P-coordinated monomeric complexes, HgX2 (dppeO)2[X = Cl (4), Br (5), I (6)]. The structures of 2, 3, 4 and 5 have been characterized crystallographically. The results indicate that the geometry around the mercury atom in each of these molecules is tetrahedral with considerable distortion. The 31P NMR spectra of the 1:1 complexes indicate the dissociation of the Hg–O bond in solution. - PublicationMétadonnées seulementSynthesis and characterization of tetrahedral Ru3O clusters with intrinsic framework chirality: a chiral probe of the intact cluster catalysis concept. [Erratum to document cited in CA144:088385](2006)
; ; ; - PublicationAccès libreSynthesis and structural analysis of palladium biscarbene complexes derived from bisimidazolium ligand precursors(2006)
; Albrecht, MartinThe palladation of potentially chelating bisimidazolium ligand precursors with palladium acetate gives bridging bimetallic, chelating monometallic, and homoleptic tetracarbene complexes. The coordination mode of the biscarbene ligand has been identified by spectroscopic analysis and crystallographic characterization of representative complexes, including the first example of a biscarbene A-frame structure. Substantial concentrations of free acetate favor the formation of tetracarbene over biscarbene palladium complexes, while in the absence of a base, the concentration of reactants influences the selectivity for bridging bimetallic versus chelating monometallic species. Preliminary kinetic and mechanistic studies indicate that chelating biscarbene palladium acetate complexes are intermediates in the formation of the homoleptic tetracarbene complexes. Probably due to the high trans effect of the biscarbene ligand, such complexes are more efficient palladating agents for bisimidazolium salts than palladium acetate.