Propuesta de intervención en el Cuarto Real de Santo Domingo (Granada)

El Cuarto Real de Santo Domingo en Granada es, -en palabras de los autores de este artículo-, el edificio clave para el análisis de la arquitectura y la decoración en la transición del arte postalmohade al nazarí. Es de destacar el rigor de la investigación, la minuciosidad de los levantamientos gráficos mediante técnicas taquimétricas y fotogramétricas, así como la apuesta comprometida contenida en la propuesta de liberación y de repristinación que incluye la alberca y el jardín.Ayuntamiento de GranadaPeer reviewe

(Di-tert-butyl­phosphan­yl)bis­(diphenyl­phosphan­yl)phosphane

The title phosphane, C32H38P4 or (Ph2P)2P(PtBu2), has a P atom that is linked to another three P atoms in a pyramidal configuration; the P—P distances in the range 2.2231 (7)–2.2446 (7) Å indicate that the P—P bonds are single bonds

A Spirocyclic P-S Cage Cation: Synthesis and Formation of P7S6I2+

Upon ionization of the P4S3I2 molecule with Ag[Al(OR)4], a highly reactive sulfonium cation P4S3I+ is generated (NMR simulated and assigned). At -80 °C this cation reacts with additional P4S3I2 to give either an iodophosphonium P4S3I3+ cation (NMR simulated and assigned) and P4S3 or to give several isomers of a metastable compound that is probably P8S3I3+. This mixture decomposes at 0 °C to give only three isomers of the spirocyclic P7S6I2+ cage cation (31P NMR simulated and assigned, X-ray of one isomer, IR assigned). The oxidation of the [Ag(P4S3)2]+ complex by I2 also resulted in the formation of P7S6I2+, but with more by-products. The spirocyclic 15-atom cage of P7S6I2+ has no precedent and contains the first phosphonium center bonded only to P and S atoms. This structural element gives the first experimental clue as to how formal charge-bearing elements in the still unknown class of binary P-Ch (Ch = chalcogen) or homopolyatomic P cations may be constructed

Cationic P-S-X cages (X=Br, I)

The first condensed-phase preparation of ternary P-Ch-X cations (Ch=O-Te, X=F-I) is reported: [P5S3X2]+, [P5S2X2]+, and [P4S4X]+ (X=Br, I). [P5S3X2]+ is formed from the reaction of the Ag+/PX3 reagent with P4S3. The [P5S3X2]+ ions have a structure that is related to P4S5 by replacing P=S by P+-X and S in the four-membered ring by P(X). We provide evidence that the active ingredient of the Ag+/PX3 reagent is the (H2CCl2)Ag-X-PX2+ cation. The latter likely reacts with the HOMO of P4S3 in a concerted HOMO-LUMO addition to give the P5S3X2+ ion as the first species visible in situ in the low-temperature 31P NMR spectrum. The [P5S3X2]+ ions are metastable at -78 °C and disproportionate at slightly higher temperatures to give [P5S2X2]+ and [P4S4X]+, probably with the extrusion of 1/n (PX)n (X=Br, I). All six new cage compounds have been characterized by multinuclear NMR spectroscopy and, in part, by IR or Raman spectroscopy. The [P5S2X2]+ salts have a nortricyclane skeleton and were also characterized by X-ray crystallography. The structure of the [P4S4X]+ ion is related to that of P4S5 in that the exo-cage P=S bond is replaced by an isoelectronic P+-X moiety

Enzyme induction in cultured cells

Hahlbrock K, Betz B, Gardiner SE, et al. Enzyme induction in cultured cells. Presented at the Proceedings of the 4th International Congress of Plant Tissue and Cell Culture, Calgary, Alberta, Canada