Gold(I) and silver(I) complexes containing a tripodal tetraphosphine ligand: influence of the halogen and stoichiometry on the properties. The X-ray crystal structure of two gold(I) dimeric aggregates.

Complexes of the type [Au2(micro-PP3)2]X2 [X=Cl (), Br (), I ()], [Ag2(micro-PP3)2](NO3)2 (), Ag(PP3)Cl (), M3(micro-PP3)X3 [M=Au, X=Cl (), Br (), I (); M=Ag, X=NO3 ()] and Au4(micro-PP3)X4 [X=Cl (), Br (), I ()] have been prepared by interaction between gold(I) or silver(I) salts and the ligand tris[2-(diphenylphosphino)ethyl]phosphine (PP3) in the appropriate molar ratio. Microanalysis, mass spectrometry, IR and NMR spectroscopies and conductivity measurements were used for characterization. and are ionic dinuclear species containing four-coordinate gold(i) and four/three coordinate silver(i), respectively. Solutions of behave as mixtures of complexes in a 2:1 [Au2(micro-PP3)X2; X=Cl(), Br(), I()] and 4:1 () metal to ligand ratio. and react with free PP(3) in solution to generate the ionic compounds and , respectively. Complexes and , with four linear PAuX fragments per molecule, were shown by X-ray diffraction to consist of dimeric aggregates via close intermolecular gold(I)gold(I) contacts of 3.270 A () and 3.184 A (). The resultant octanuclear systems have an inversion center with two symmetry-related gold(I) atoms being totally out of the aurophilic area and represent a new form of aggregation compared to that found in other halo complexes of gold(I) containing polyphosphines. The luminescence properties of the ligand and complexes, in the solid state, have been studied. Most of the gold systems display intense luminescent emission at room and low temperature. The influence of the halogen on the aurophilic contacts of compounds with a 4:1 metal to ligand ratio results in different photophysical properties, while and are luminescent complex is nonemissive. The luminescence increases with increasing the phosphine/metal ratio affording for complexes , without aurophilic contacts, the stronger emissions. Silver complexes and are nonemissive at room temperature and show weaker emissions than gold(I) species at 77 K.

[Foreign-body aspiration]. / Aspiración de cuerpos extraños.

Aspiration of foreign bodies is a common accident during childhood. In its diagnosis, both an accurate clinical history and a high degree of suspicion must be taken into account. Without an early diagnosis and its correct treatment, it remains a major cause of morbidity and mortality in children. The objective was to analyze the incidence, diagnosis and therapy of foreign bodies in the airways in pediatric patients. We have conducted a retrospective study of sixty-four patients admitted to our Pediatric Intensive Care Unit during the last eight years with a suspected diagnosis of a foreign body in the airways. Accordingly, we have evaluated the clinical and epidemiological data, as well as the diagnostic and therapeutic methods used. Half of the patients were under two years of age. Cough was a constant finding in all cases. Most of the cases showed air-trapping in chest X-rays, and in almost all cases a bronchoscopy was needed to remove the foreign body. The aspirated material found was mostly frequently found was a piece of food and it was most commonly placed in the main right bronchus. We underline the importance of prevention to avoid this problem by leaving out of the child's reach dry fruits and other small objects that can be easily introduced into their mouths.