Showing papers by "Juan Forniés published in 2010"

Structural and Luminescence Studies on π···π and Pt···Pt Interactions in Mixed Chloro-Isocyanide Cyclometalated Platinum(II) Complexes†

Abstract: [Pt(bzq)Cl(CNR)] [bzq = benzoquinolinate; R = tert-butyl (tBu 1), 2-6-dimethylphenyl (Xyl 2), 2-naphthyl (2-Np 3)] complexes have been synthesized and structurally and photophysically characterized. 1 was found to co-crystallize in two distinct pseudopolymorphs: a red form, which exhibits an infinite 1D-chain ([1]∞) and a yellow form, which contains discrete dimers ([1]2), both stabilized by interplanar π···π (bzq) and short Pt···Pt bonding interactions. Complex 3, generated through the unexpected garnet-red double salt isomer [Pt(bzq)(CN-2-Np)2][Pt(bzq)Cl2] 4, crystallizes as yellow Pt···Pt dimers ([3]2), while 2 only forms π···π (bzq) contacting dimers. Their electronic absorption and luminescence behaviors have been investigated. According to Time-Dependent Density Functional Theory (TD-DFT) calculations, the lowest-lying absorption (CH2Cl2) has been attributed to combined 1ILCT and 1MLCT/1ML′CT (L = bzq, L′ = CNR) transitions, the latter increasing from 1 to 3. In solid state, while the yellow form [1...

Trapping a Difluorocarbene–Platinum Fragment by Base Coordination

Abstract: The trifluoromethyl group (CF3) when bound to an element E of medium to high electronegativity behaves as a monovalent substituent with a high thermal stability and a marked chemical inertness. This low-reactivity profile together with its unique combination of electronic and steric properties have definitely encouraged the increasing use of CF3 as a robust terminal group in modern organic chemistry. When bound to an electropositive atom, however, CF3 becomes more reactive: a-fluoride elimination and the formation of a difluorocarbene unit (Scheme 1) is a general reaction path-

Synthesis and characterization of neutral and anionic carbonyl derivatives of palladium(II)

Abstract: The action of CO on the solvento-complexes cis-[PdR2(thf)2] [R = C6F5 (1), C6Cl5 (2)] at low temperature gives cis-[PdR2(CO)2] [R = C6F5 (3), C6Cl5 (4)] in good yield by simple replacement of the highly labile thf molecules. These are rare cases of PdII dicarbonyl compounds, whose characterization relies on spectroscopic and analytic data. The crystal structure of the square-planar platinum homologue cis-[Pt(C6Cl5)2(CO)2] is also presented. CO can split the double bridging-system in the dinuclear species [{PdR2}2(μ-X)2]2− giving the homologous series of anionic monocarbonyl PdII derivatives with formula [cis-PdR2X(CO)]− (5–10: R = C6F5, C6Cl5; X = Cl, Br, I), which were isolated (except for the R = C6F5 and X = I) and suitably characterized. Characterization includes the crystal and molecular structure of [PPh3Me][cis-Pd(C6F5)2Br(CO)] (6′). The anionic species [NBu4][cis-Pd(C6F5)2Cl(CO)] (5) reacts with neutral cis-[Pd(C6F5)2(CO)2] (3) under CO extrusion, affording the dinuclear derivative [NBu4][{Pd(C6F5)2(CO)}2(μ-Cl)] (11), which contains a single unsupported halide bridge (X-ray diffraction). Complex 11 can be considered as modelling a possible intermediate step in intermolecular CO substitution reactions that are easily undergone by PdII halo carbonyl species.