Intermolecular and intramolecular halogen···π interactions in benzylic halides (Ph-CR2-X; X = F, Cl, Br and I) derived from 7-phenylnorbornane were investigated. The imposed geometry of the 7-arylnorbornane moiety prevents the participation of intramolecular attractive interactions between the σ-hole region of the halogen atom and the π electrons of the aromatic ring. Crystallographic data show intermolecular halogen bonds in iodide 1 and bromide 2 in the solid state. On the other hand, both UV-Vis and D-NMR data suggest the occurrence of intramolecular interactions between the halogen atoms and the phenyl rings in these compounds in solution. To provide more insight into the nature of the observed stabilizing interactions, density functional calculations were also carried out. These computations confirm the presence of genuine lone pairπ intramolecular interactions which strongly affect the stability and the electronic structure of these species.

A new molecular receptor (1) for ammonium recognition has been designed and constructed by using only carbon atoms. This molecular receptor can co-exist in two different isoenergetic conformations but, upon complexation, the conformers are no longer isoenergetic, and a basket-shaped conformation becomes clearly more stable. The pre-organised tetrahedral structure of this basket-shaped molecule favours the complexation of ammonium ions by N-H⋅⋅⋅π interactions with the four phenyl groups of the host. A similar behaviour is not observed in a similar, but less pre-organised, reference molecule. ESI-MS competition experiments show that 1 is able to bind NH(4)(+) over K(+) selectively. This is the first example of a neutral molecular receptor that shows a remarkable NH(4)(+)/K(+) selectivity. DFT-calculations provide insight into the nature of host-guest interactions of both 1⋅NH(4)(+) and 1⋅K(+) complexes as well as in the mechanism involved in multiple cation-π interactions and the influence of these interactions on the conformational stability and the selective binding of the host.

We report hereon the synthesis, spectroscopic properties and computational studies of novel aromatic homoconjugated compounds derived from 7,7‐diphenylnorbornane (DPN). The UV/Vis spectra of these compounds show bands corresponding to the respective chromophores as well as new homoconjugation bands and charge transfer absorptions in D–DPN–A push‐pull derivatives. Homoconjugation between the aromatic rings strongly depends on the nature of the substitution at the aryl moieties. Therefore, electronic communication by homoconjugation can be easily tuned by controlling the electronic nature and positions of the substituents. The strong homoconjugative interaction is also reflected in the reactivity, NMR spectra and NLO properties of the compounds studied. DFT calculations nicely agree with the experimental data and shed light on the electronic delocalization via homoconjugation.

Learning to read is one of the most important cognitive milestones in the human social environment. One of the most accepted models explaining such process is the Double-Route Cascaded Model. It suggests the existence of two reading strategies: lexical and sublexical. In the Spanish language there are some contradictions about how these strategies are applied for reading. In addition, there are only a few studies dealing with the analysis of shifts between them, achieving a fluent reading process. In this paper we use a reading task including words and pseudowords for characterizing the cost of shifting between reading strategies in children with developmental dyslexia and normal controls. Our results suggest the presence of both strategies in these two experimental groups. In controls, both strategies become more efficient in correspondence to the increased exposition to written material. However, in children with developmental dyslexia only the lexical strategy exhibits such improvement. Their also point to a low cost for shifting between strategies in controls and a much more significant one in children with developmental dyslexia, differentiating subgroups with distinct shifting patterns.El aprendizaje de la lectura constituye uno de los hitos cognitivos más importantes del entorno social humano. Uno de los modelos de lectura más aceptados ha sido el Modelo de Doble Ruta en Cascada que sugiere la existencia de dos estrategias de lectura: lexical y sublexical. En el idioma español existen datos contradictorios acerca de cómo se aplican estas estrategias y no hay estudios que describan cómo se realizan los cambios de una a otra para lograr una lectura fluida. En este trabajo utilizamos una tarea de lectura de palabras y pseudopalabras para caracterizar el costo de cambio de una a otra estrategia en niños buenos lectores y niños con dislexia del desarrollo. Nuestros resultados sugieren la presencia de ambas estrategias en los dos grupos. En los niños buenos lectores ambas estrategias se hacen más eficientes con el grado de exposición a la lectura. Sin embargo, en los niños disléxicos esto solo ocurre en la estrategia lexical. Además, indican que los niños buenos lectores desarrollan un bajo costo en el cambio de estrategia de lectura mientras que un subgrupo de niños disléxicos presenta un costo mayor, conformándose subgrupos con patrones diferentes de afectación selectiva. Palabras clave: estrategias de lectura, cambio, español, niños disléxicos.

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