Camino Bartolomé

Gold(I) Complexes with Hydrogen-Bond Supported Heterocyclic Carbenes as Active Catalysts in Reactions of 1,6-Enynes

Complexes [AuCl{C(NHR)(NHPy-2)}] (Py-2 ) 2-pyridyl; R ) Me, tBu, nBu, iPr, nheptyl) have been prepared in amodular way from [AuCl(CNPy-2)]. The carbene moiety has a hydrogen-bond supported heterocyclic structure similar to the nitrogen heterocyclic carbenes in the solid state, and in CH2Cl2 or acetone solution, which is open in the presence of MeOH. The compounds are good catalysts for the skeletal rearrangement of enynes, and for the methoxycyclization of enynes. In contrast, the complexes [AuCl{C(NHR)(NHPy-4)}] are scarcely active due to the blocking effect of the coordination position required for the catalysis by the nitrogen of the NHPy-4 group.

Luminescent Gold(I) Carbenes from 2-Pyridylisocyanide Complexes: Structural Consequences of Intramolecular versus Intermolecular Hydrogen-Bonding Interactions

Isocyanide [AuX(CNPy-2)] (X = Cl, C6F5, fluoromesityl, 1/2 octafluorobiphenyl) and carbene [AuX{C(NR1R2)(NHPy-2)}] (R1R2NH = primary or secondary amines or 1/2 primary diamine) gold(I) complexes have been synthesized and characterized. For X = Cl, the carbene complexes show aurophilic interactions. The fragment NHPy-2, formed in the carbenes, can give rise to intra- (for primary amines) or intermolecular (for secondary amines) hydrogen bonds, depending on the amine used. These bonds and contacts have been studied in the solid state and in solution. The intermolecular hydrogen bonds are split in an acetone solution, but the intramolecular ones, which close a six-membered ring, survive in solution. Except for the fluoromesityl derivatives, the carbene complexes display luminescent properties.

Self‐Assembly of Pyramidal Tetrapalladium Complexes with a Halide at the Apex

Halide ions act as the template for the self-assembly of tetrapalladium macrocyclic pyramidal structures. These undergo easy inversion in which the halide ion apparently jumps across the macrocycle.

[Pd(Fmes)I{NMe2(CH2-o-C6H4-I)-N, I}], a palladium(II) complex with I- and organic iodide as trans ligands

The treatment of [Pd(dmba)(Fmes)(OH2)] with I2 leads to the formation of [Pd(Fmes)I{NMe2(CH2-o-C6H4-I)-N,I}]. The X-ray structure shows that a new halocarbon ligand, (2-iodobenzyl)dimethylamine has been formed and is acting as N–I chelate. The two different types of iodine, one iodide ligand and one organic iodide coordinated to Pd, are mutually trans and display essentially identical Pd–I distances.

Gold(I)–carbenes derived from 4-pyridylisocyanide complexes: supramolecular macrocycles supported by hydrogen bonds, and luminescent behavior

Monomeric gold(I) carbenes of the type [AuR[C(NR1R2)(NHPy-4)]] (Py-4 = 4-pyridyl) have been prepared with R = C6F5, Fmes (2,4,6-tris(trifluoromethyl)phenyl) by reaction of the corresponding isocyanide compounds [AuR(CNPy-4)] with primary or secondary amines. The single crystal X-ray diffraction structures of [Au(C6F5)[C(NEt2)(NHPy-4)]].OH2, [Au(Fmes)[C(NEt2)(NHPy-4)]], and [Au(Fmes)[C(NHMe)(NHPy-4)]] show that the presence of the NHPy-4 moiety formed induces the formation of supramolecular macrocycles only supported by hydrogen bond interactions, either with N-H groups of other molecules (tetrameric macrocycles), or with water molecules (dimeric macrocycles). Dimeric gold(I) carbenes were also produced using a diamine to form a bridging carbene, or using octafluorobiphenyl to form a Au-C6F4-C6F4-Au bridge, but the solid state structures of these dimers could not be solved. Most of the complexes herein described display luminescent properties.

Is there any bona fide example of O-H···F-C bond in solution? The cases of HOC (CF3 )2 (4 -X -2,6 -C6H2 (CF3 )2) (X = Si(i-Pr)3, CF3)

The reinvestigation of the title compounds, which are the only examples reported to show experimentally (by NMR) O-H...F-C bonds in solution proves that the NMR data were misinterpreted and the restrictions to rotation of one CF(3) group are due to crowding, not to intramolecular O-H...F-C bond.

Microporous Polymer Networks for Carbon Capture Applications

A new generation of porous polymer networks has been obtained in quantitative yield by reacting two rigid trifunctional aromatic monomers (1,3,5-triphenylbenzene and triptycene) with two ketones having electron-withdrawing groups (trifluoroacetophenone and isatin) in superacidic media. The resulting amorphous networks are microporous materials, with moderate Brunauer-Emmett-Teller surface areas (from 580 to 790 m2 g-1), and have high thermal stability. In particular, isatin yields networks with a very high narrow microporosity contribution, 82% for triptycene and 64% for 1,3,5-triphenylbenzene. The existence of favorable interactions between lactams and CO2 molecules has been stated. The materials show excellent CO2 uptakes (up to 207 mg g-1 at 0 °C/1 bar) and can be regenerated by vacuum, without heating. Under postcombustion conditions, their CO2/N2 selectivities are comparable to those of other organic porous networks. Because of the easily scalable synthetic method and their favorable characteristics, these materials are very promising as industrial adsorbents.