Reactions at mild temperatures of the acetonitrile adducts [M(CO) 3 (NCMe) 3 ] (M ) Mo (1), W (2)) with various substituted cyclopentadienes in THF give the hydrido derivatives 17)) in isolated yields of 60-70%. THF solutions of derivatives 5a, 7a, and 8a undergo isomerization of the cyclopentadienyltethered-allyl unit to give the corresponding methyl-vinyl-dimethylsilyl-η 5 -cyclopentadienyl hydrido compounds) in final a:b ratios of ca. 2:1, 2:1, and 1:1, respectively. Solvent polarity seems to be crucial in these transformations. Dehydrogenation and desilylation of 5a in THF solutions to give the dinuclear derivative [Mo{η 5 -C 5 H 4 Si(CH 3 ) 2 (CH 2 CHdCH 2 )}(CO) 3 ] 2 ( 9) and [MoH(η 5 -C 5 H 5 )(CO) 3 ] (15), respectively, are processes competitive with the allyl isomerization. Treatment of 5a and 7a with equimolar amounts of ONMe 3 permits isolation of pure compound 9 and [W{η 5 -C 5 H 4 Si(CH 3 ) 2 (CH 2 CHdCH 2 )}-(CO) 3 ] 2 (10) in isolated yields of 80-90%. Coordination of the olefin pendant unit to the metal was detectable only by reaction of 5a and 7a with [CPh 3 ][B(C 6 F 5 ) 4 ] to give the cationic species [M{η 5 -C 5 H 4 Si-(CH 3 ) 2 (CH 2 CHdCH 2 )}(CO) 3 ][B(C 6 F 5 ) 4 ] (M ) Mo (18), W ( 19)). Molecular structure determinations by X-ray diffraction methods for derivatives 8a and 9 are also reported.

The reaction of B(C6Fs) 3 with the tetramethyl zirconium fulvalene derivative [Zr(CsH5XCH3)2]2(/x-r/5:rl5-CloHs ) la in CH2CI 2 at -60°C gives the cationic compound [{Zr(CsHs)}2(/X-CH3)(/X-CH2X/x-@:@-CmHs)]+[BMe(C6Fs)3] -2a. A similar reaction using the 1,3-di(tert-butyl) cyclopentadienyl derivative [Zr(1,3-tBu2-CsH3)(CH3)2]2(/x-r/5:@-CIoH~) lb affords a mixture of compounds, none of them being isolable as pure substances. However, monitoring the reaction of B (C6F5)

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The electronic distribution of some haloethynylbenzene derivatives may favour the formation of two-dimensional organizations by combining halogen and hydrogen bonds. In order to highlight this strategy we have prepared seven cocrystals and analyzed their structures. 1,4-Bis(iodoethynyl)benzene (p-BIB), 1,4-bis(bromoethynyl)benzene (p-BBrB) and 1,3bis(iodoethynyl)benzene (m-BIB) were used as halogen bond donors and 1,2-bis(4-pyridyl)ethylene (BPE), pyridazine, propanone, hexamethylenetetramine (HTMA) and 2,8-dimethyl-6H,12H-5,11methanodibenzo[b,f][1,5]diazocine (Tröger's base, TB) were employed as halogen bond acceptors. The crystal structures of seven halogen-bonded complexes show C−X•••Y (X = I, Br; Y = N, O) distances shorter than the sum of the van der Waals radii and six of them contain the edge-to-edge C−H•••X (X = I, Br) supramolecular hydrogen bond synthon. The stabilization energies with BSSE correction of hydrogen bond synthons have been determined by DFT calculations, and they are in the range 2.9 to 5.7 kcalmol-1. To gain a deeper understanding of these interactions, Non-Covalent Interactions (NCI) methodology was also applied.

La Constitución española reservó al Poder Legislativo estatal la competencia para fijar los servicios fundamentales mínimos en sanidad (art. 149.1.16 CE), mientras que son las CC. AA. las competentes para su desarrollo legislativo y gestión. Durante estos más de cuarenta años de vigencia del texto constitucional se ha producido una progresiva descentralización en la gestión sanitaria, que culminaría en 2001, a la par de una importante centralización legislativa. Este reparto competencial contrasta con el sistema de financiación diseñado para la prestación sanitaria desde 2001. Un sistema en el que el peso de la responsabilidad de gasto recae fundamentalmente en las CC. AA. El presente trabajo hace un análisis del reparto competencial vigente en España en materia sanitaria y lo relaciona con el sistema de financiación diseñado, poniendo de manifiesto la incongruencia que al respecto existe en el diseño de la prestación sanitaria.