Juan Forniés

Bio: Juan Forniés is an academic researcher from University of Zaragoza. The author has contributed to research in topics: Palladium & Platinum. The author has an hindex of 45, co-authored 363 publications receiving 8554 citations. Previous affiliations of Juan Forniés include Spanish National Research Council.

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...

New Water Soluble and Luminescent Platinum(II) Compounds, Vapochromic Behavior of [K(H2O)][Pt(bzq)(CN)2], New Examples of the Influence of the Counterion on the Photophysical Properties of d8 Square-Planar Complexes

Abstract: This work describes the synthesis of compounds [Pt(C∧N)(NCMe)2]ClO4 (C∧N = 7,8-benzoquinolinato (bzq), 2-phenylpyridinato (ppy)) and their use as precursors for the preparation of the cyanido complexes [Pt(C∧N)(CN)2]−, which were isolated as the potassium, [K(H2O)][Pt(C∧N)(CN)2] [C∧N = bzq (3a), ppy (4a)], and the tetrabutylammonium, NBu4[Pt(C∧N)(CN)2] [C∧N = bzq (5), ppy (6)], salts. The difference in the cation has an influence on the solubility, color, and emission properties of these compounds. Compounds 5 and 6 are yellow and soluble in organic solvents, while the potassium salts are also soluble in water and exhibit two forms: the water-containing [K(H2O)][Pt(C∧N)(CN)2] [C∧N = bzq (3a), ppy (4a)] complexes and the anhydrous ones K[Pt(C∧N)(CN)2] [C∧N = bzq (3b), ppy (4b)], the former being strongly colored [red (3a) or purple (4a)] and the latter being yellow. Compounds 3a and 4a transform reversibly into the yellow, 3b and 4b, compounds upon desorption/ reabsorption of water molecules from the envir...

Highly luminescent half-lantern cyclometalated platinum(II) complex: Synthesis, structure, luminescence studies, and reactivity

Abstract: The half-lantern compound [{Pt(bzq)(μ-C7H4NS2-κN,S)}2]·Me2CO (1) was obtained by reaction of equimolar amounts of potassium 2-mercaptobenzothiazolate (KC7H4NS2) and [Pt(bzq)(NCMe)2]ClO4. The Pt(II)···Pt(II) separation in the neutral complex [{Pt(bzq)(μ-C7H4NS2-κN,S)}2] is 2.910 (2) A, this being among the shortest observed in half-lantern divalent platinum complexes. Within the complex, the benzo[h]quinoline (bzq) groups lie in close proximity with most C···C distances being between 3.3 and 3.7 A, which is indicative of significant π–π interactions. The reaction of 1 with halogens X2 (X2 = Cl2, Br2, or I2) proceeds with a two-electron oxidation to give the corresponding dihalodiplatinum(III) complexes [{Pt(bzq)(μ-C7H4NS2-κN,S)X}2] (X = Cl 2, Br 3, I 4). Their X-ray structures confirm the retention of the half-lantern structure and the coordination mode of the bzq and the bridging ligand μ-C7H4NS2-κN,S. The Pt–Pt distances (Pt–Pt = 2.6420(3) A 2, 2.6435(4) A 3, 2.6690(3) A 4) are shorter than that in 1 bec...

Mono- and bi-nuclear anionic pentafluorophenyl complexes of palladium(II) and platinum(II)

Abstract: The arylation of K2[MCl4], [MCl2(tht)2], MCl2, or [NBu4]2[M2(µ-Br)2Br4](M = Pd or Pt; tht = tetrahydrothiophen) with LiR or MgBrR (R = C6F5) leads to novel mono- and bi-nuclear anionic organo-derivatives of the general formulae [MR3(tht)]–, [MR4]2–, and [M2(µ-Br)2R4]2–, which have been isolated as tetra-alkylammonium salts. Reaction of compounds of the [MR3(tht)]– type with neutral ligands leads to the substitution of tht by L, that of [PdR4]2– with PdCl2 gives rise to the formation of [Pd2(µ-Cl)2R4]2–, whilst [M2(µ-X)2R4]2– reacts with alkali-metal salts of Br–, I–, or SCN– to give (without cleavage of the bridging system) the corresponding complexes. Twenty anionic complexes of these three novel types have been isolated and characterized.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Palladium(II)-catalyzed C-H activation/C-C cross-coupling reactions: versatility and practicality.

Abstract: Pick your Pd partners: A number of catalytic systems have been developed for palladium-catalyzed CH activation/CC bond formation. Recent studies concerning the palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle are discussed (see scheme), and the versatility and practicality of this new mode of catalysis are presented. Unaddressed questions and the potential for development in the field are also addressed. In the past decade, palladium-catalyzed CH activation/CC bond-forming reactions have emerged as promising new catalytic transformations; however, development in this field is still at an early stage compared to the state of the art in cross-coupling reactions using aryl and alkyl halides. This Review begins with a brief introduction of four extensively investigated modes of catalysis for forming CC bonds from CH bonds: PdII/Pd0, PdII/PdIV, Pd0/PdII/PdIV, and Pd0/PdII catalysis. A more detailed discussion is then directed towards the recent development of palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle. Despite the progress made to date, improving the versatility and practicality of this new reaction remains a tremendous challenge.

Chemical Redox Agents for Organometallic Chemistry

Abstract: 1. Advantages of Chemical Redox Agents 878 2. Disadvantages of Chemical Redox Agents 879 C. Potentials in Nonaqueous Solvents 879 D. Reversible vs Irreversible ET Reagents 879 E. Categorization of Reagent Strength 881 II. Oxidants 881 A. Inorganic 881 1. Metal and Metal Complex Oxidants 881 2. Main Group Oxidants 887 B. Organic 891 1. Radical Cations 891 2. Carbocations 893 3. Cyanocarbons and Related Electron-Rich Compounds 894

ONIOM: A Multilayered Integrated MO + MM Method for Geometry Optimizations and Single Point Energy Predictions. A Test for Diels−Alder Reactions and Pt(P(t-Bu)3)2 + H2 Oxidative Addition

Abstract: The new ONIOM (our own n-layered integrated molecular orbital and molecular mechanics) approach has been proposed and shown to be successful in reproducing benchmark calculations and experimental results. ONIOM3, a three-layered version, divides a system into an active part treated at a very high level of ab initio molecular orbital theory like CCSD(T), a semiactive part that includes important electronic contributions and is treated at the HF or MP2 level, and a nonactive part that is handled using force field approaches. The three-layered scheme allows us to study a larger system more accurately than the previously proposed two-layered schemes IMOMO, which can treat a medium size system very accurately, and IMOMM, which can handle a very large system with modest accuracy. This three-layered scheme has been applied to activation barriers for the Diels−Alder reaction of acrolein + isoprene, acrolein + 2-tert-butyl-1,3-butadiene, and ethylene + 1,4-di-tert-butyl-1,3-butadiene. In general, the results for b...