New insights into frustrated Lewis pairs: structural investigations of intramolecular phosphane-borane adducts by using modern solid-state NMR techniques and DFT calculations

Covalent bonding interactions between the Lewis acid and Lewis base functionalities have been probed in a series of “frustrated Lewis pairs” (FLPs) (mainly substituted vinylene linked intramolecular phosphane–borane adducts), using solid-state nuclear magnetic resonance techniques and accompanying DFT calculations. Both the 11B NMR isotropic chemical shifts and nuclear electric quadrupolar coupling parameters turn out to be extremely sensitive experimental probes for such interactions, revealing linear correlations with boron–phosphorus internuclear distances. The principal component Vzz of the 11B electric field gradient tensor is tilted slightly away (∼20°) from the boron–phosphorus internuclear vector, leading to an improved understanding of the remarkable reactivity of the FLPs. Complementary 31P{1H}-CPMAS experiments reveal significant 31P–11B scalar spin–spin interactions (1J ≈ 50 Hz), evidencing covalent bonding interactions between the reaction centers. Finally, 11B{31P} rotational echo double resonance (REDOR) experiments show systematic deviations from calculated curves based on the internuclear distances from X-ray crystallography. These deviations suggest non-zero contributions from anisotropic indirect spin–spin (J anisotropy) interactions, thereby offering additional evidence for covalent bonding.SFB 858 “Cooperative Systems in Chemistry”Fonds der Chemischen IndustrieNRW Forschungsschule “Molecules and Materials

Herramientas para hacer frente a la violencia de género: Aportes y experiencias desde los feminismos

Herramientas para hacer frente a la violencia de género, aportes y experiencias desde los feminismos, propone un recorrido posible para pensar e identificar -desde los feminismos- la violencia de género como expresión del sistema patriarcal en el que vivimos. Es parte de las herramientas para intervenir colectivamente en la prevención y el acompañamiento a mujeres e identidades disidentes que atraviesan múltiples violencias de género. En la obra pueden encontrar una propuesta para elaborar estrategias territoriales para prevenirla y acompañar a aquellas personas que la estén transitando, además de una definición de violencia de género, sus tipos y modalidades, la explicación sobre el proceso judicial ante situaciones concretas, los derechos y leyes que tenemos, la especificación de los fueros que tienen competencia y la caracterización de lxs actorxs que intervienen. “Este es un material a completar por cada experiencia, por cada organización y cada persona que lo tenga en sus manos, pues la violencia de género se reactualiza con el paso del tiempo (…) Creemos que la mejor manera de enfrentarla es desde la organización feminista y la potencia creativa: he aquí algunos pasos posibles para iniciar ese camino”, comentan las autoras en el libro.Fil: Bolla, Luisina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Dagnino Contini, Alida. Universidad Nacional de La Plata. Facultad de Periodismo y Comunicación Social; Argentina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Ekkert, Olga. Universidad Nacional de La Plata. Facultad de Periodismo y Comunicación Social; ArgentinaFil: Fernandez Michelli, Virginia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; ArgentinaFil: Gotta, Maria Eugenia. Universidad Nacional de La Plata. Facultad de Ciencias Jurídicas y Sociales; ArgentinaFil: Segura, Valeria. Universidad Nacional de La Plata. Facultad de Ciencias Jurídicas y Sociales; ArgentinaFil: Siri, Aldana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; ArgentinaFil: Stange, Carolina. Universidad Nacional de La Plata. Facultad de Psicología; ArgentinaFil: Talamonti, Paula. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentin

Rhodium Catalyzed, Carbon–Hydrogen Bond Directed Hydrodefluorination of Fluoroarenes

[Cp*RhCl­(μ-Cl)]₂ is reported as a highly efficient and selective precatalyst for the hydrodefluorination of perfluoroarenes using a hydrocarbon-soluble aluminum dihydride as the terminal reductant. Reactions are directed to cleave a C–F bond adjacent to an existing C–H bond with high regioselectivity (98.5–99%). A heterobimetallic complex containing an extremely rare Al–H–Rh functional group has been isolated and shown to be catalytically competent

Rhodium Catalyzed, Carbon–Hydrogen Bond Directed Hydrodefluorination of Fluoroarenes

[Cp*RhCl­(μ-Cl)]₂ is reported as a highly efficient and selective precatalyst for the hydrodefluorination of perfluoroarenes using a hydrocarbon-soluble aluminum dihydride as the terminal reductant. Reactions are directed to cleave a C–F bond adjacent to an existing C–H bond with high regioselectivity (98.5–99%). A heterobimetallic complex containing an extremely rare Al–H–Rh functional group has been isolated and shown to be catalytically competent

New Insights into Frustrated Lewis Pairs: Structural Investigations of Intramolecular Phosphane–Borane Adducts by Using Modern Solid-State NMR Techniques and DFT Calculations

Covalent bonding interactions between the Lewis acid and Lewis base functionalities have been probed in a series of “frustrated Lewis pairs” (FLPs) (mainly substituted vinylene linked intramolecular phosphane–borane adducts), using solid-state nuclear magnetic resonance techniques and accompanying DFT calculations. Both the ¹¹B NMR isotropic chemical shifts and nuclear electric quadrupolar coupling parameters turn out to be extremely sensitive experimental probes for such interactions, revealing linear correlations with boron–phosphorus internuclear distances. The principal component <i>V</i>_<i>zz</i> of the ¹¹B electric field gradient tensor is tilted slightly away (∼20°) from the boron–phosphorus internuclear vector, leading to an improved understanding of the remarkable reactivity of the FLPs. Complementary ³¹P­{¹H}-CPMAS experiments reveal significant ³¹P–¹¹B scalar spin–spin interactions (¹<i>J</i> ≈ 50 Hz), evidencing covalent bonding interactions between the reaction centers. Finally, ¹¹B­{³¹P} rotational echo double resonance (REDOR) experiments show systematic deviations from calculated curves based on the internuclear distances from X-ray crystallography. These deviations suggest non-zero contributions from anisotropic indirect spin–spin (<i>J</i> anisotropy) interactions, thereby offering additional evidence for covalent bonding

Remarkable coordination behavior of alkyl isocyanides toward unsaturated vicinal frustrated P/B Lewis pairs

The conjugated frustrated phosphane/borane Lewis pairs formed by 1,1-carboboration of a substituted diphenylphosphino acetylene, undergo a synergistic 1,1-addition reaction to n-butyl isocyanide with formation of new B-C and P-C bonds to the former isonitrile carbon atom. Using tert-butyl isocyanide dynamic behaviour between the isocyanide-[B] adduct and the 1,1-addition product formation was observed in solution. The different modes of isocyanide binding to the FLPs in the solid state were characterized using X-ray crystal structure analyses and comprehensive 11B and 31P solid-state magicangle- spinning (MAS-) NMR experiments. The free FLP, the Lewis adduct at the borane group, and the cyclic product resulting from isocyanide addition to both reaction centers, can be differentiated via 11B and 31P isotropic chemical shifts, 11B nuclear electric quadrupole coupling constants, isotropic indirect 11B-31P spin-spin coupling constants, and 11B...31P internuclear distances measured by rotational echo double resonance.DFGFonds der Chemischen Industrie (FCI)NRW Forschungsschule “Molecules and Materials