ConspectusThe field of metallosupramolecular chemistry is clearly dominated by the use O-, N-, and P-donor Werner-type polydentate ligands. These molecular architectures are high interest because their wide range applications, which include encapsulation, stabilization reactive species, supramolecular catalysis, drug delivery, among others. Only recently, organometallic ligands have allowed preparation a variety coordination complexes, term complexes (SOCs) gaining space within chemistry....

Ru(CNC)(CO)Br2 and [Ru(CNC)2](PF6)2 complexes (CNC = 2,6-bis(butylimidazol-2-ylidene)pyridine) are accessible via a simple synthesis. The crystal structures of both have been determined by means X-ray diffractometry. catalytic activity the precursor toward hydrogen transfer from alcohols to ketones oxidation olefins confirms versatility this new phosphine-free Ru catalyst.

A comparative study on the catalytic activity of a series [IrCl(2)Cp*(NHC)] complexes in several C-O and C-N coupling processes implying hydrogen-borrowing mechanisms has been performed. The compound [IrCl(2)Cp*(I(nBu))] (Cp*=pentamethyl cyclopentadiene; I(nBu)=1,3-di-n-butylimidazolylidene) showed to be highly effective cross-coupling reactions amines alcohols, providing high yields production unsymmetrical ethers N-alkylated amines. remarkable feature is that were carried out absence base,...

Chelating bis(imidazolium) salts having (CH2)n chains of different lengths (n = 1−4) linking the diazole rings show very large reactivity differences on metalation with [(cod)RhCl]2. Long linkers favor a square-planar Rh(I) product, while short octahedral Rh(III). We ascribe origin effect to restricted rotation highly sterically anisotropic and preferred orientations these as n changes. Defining x y axes Rh−carbene bond directions, we find that tend be oriented close xy plane. This tends...

A novel class of derivatized acetylacetonate (acac) linkers for robust functionalization TiO2 nanoparticles (NPs) under aqueous and oxidative conditions is reported. The resulting surface adsorbate anchors are particularly relevant to engineering photocatalytic photovoltaic devices since they can be applied attach a broad range photosensitizers complexes not affected by humidity. Acac easily modified CuI-mediated coupling reactions provide variety scaffolds, including substituted terpy...

Four new Pd(II) complexes containing sulfonate-functionalized N-heterocyclic carbene ligands have been synthesized. All are palladium bis-NHCs, in which the adopt a monodentate, bis-chelating, and pincer coordination form, so that good comparison between their catalytic activities can be performed. The used Suzuki−Miyaura cross-coupling reaction aryl halides phenylboronic acid water iPrOH/water. bis-NHC-palladium complex 1, two NHC relative cis configuration, affords best outcomes, with high...

Triple play: A novel triphenylene-based tris(N-heterocyclic carbene) ligand with D3h symmetry and a highly π-delocalized system has been prepared coordinated to palladium gold (see figure). The catalytic activities of the new complexes have compared those related benzimidazolylidene triptycene-based in three reactions.

Abstract A series of new bridging, chelating and pincer N ‐heterocyclic carbenes Rh I III have been obtained under mild conditions. The compounds fully characterised their crystal structures determined. chelate‐pincer coordination the ligands means that stability these is significantly greater than other carbene complexes Rh. tested in catalytic reactions such as hydrogen transfer from alcohols to ketones, hydrosilylation terminal olefins alkynes; they show a high activity for both...

In an experimental and computational study, nitrogen- oxygen-containing heterocycles were compared with carbocycles as liquid substrates for hydrogen release heterogeneous catalysts. Heteroatom substitution, particularly by nitrogen, favours low temperature H2 release; indoline was fully dehydrogenated in less than 30 min Pd/C at 110 °C.

The new ligand bitriazole-2-ylidene (bitz) has been successfully coordinated to Ru(II), Pd(II), Rh(I), Rh(II), and Rh(III), showing its wide chemical versatility. Reaction of the bitz precursor salt, 1,1′-methyl-4,4′-bi-1,2,4-triazolium diiodide, with [RhCl(cod)]2 under mild conditions afforded chelate bis-chelate Rh(III) complexes, as well an unexpected metal−metal bounded di-Rh(II) species. reaction salt [(η6-p-cymene)RuCl2]2 NaOAc a mixture dimetallic Ru(II)-arene complexes. Pd(OAc)2 led...

An imidazolium salt with a fused benzoferrocenyl was synthesized. This compound used as an N-heterocyclic carbene (NHC) precursor, and the related ferrocenyl-imidazolylidene complexes Fc-NHC-MLn (MLn = IrCl(COD), IrCl(CO)2, AuCl) were synthesized fully characterized, including crystallographic characterization of some key structures. The oxidation iridium carbonyl Fc-NHC-IrCl(CO)2 acetylferrocenium tetrafluoroborate afforded oxidized ferrocenium-NHC-IrCl(CO)2 (Fe(III)) species; however...

A combination of self-complementary π-π-stacking interactions and metallophilic triggered the self-assembly a new digold(I) metallo-tweezer in presence several types M+ ions. Titrations by fluorescence spectroscopy enabled determination association constants resulting inclusion duplex complexes.

Hot-injection has become the most widespread method used for synthesis of perovskite quantum dots (QDs) with enormous interest application in optoelectronic devices. However, there are some aspects chemistry involved this that have not been completely investigated. In work, we synthesized ultra-high stable CsPbI3 QDs more than 15 months by controlling two main parameters: temperature and concentration capping ligands. By increasing ligand during QD synthesis, were able to grow a broad range...

A ferrocenyl–imidazolium salt can be employed as a precursor to stable [IrIII(H)(biscarbene)] complex (see X-ray crystal structure) under very mild conditions. The study shows that the role of base in activation imidazolium may not just simple deprotonation precursor.

A new dirhodium(I) bisimidazolium-carbene complex has been obtained and fully characterized by means of NMR spectroscopy single-crystal X-ray diffraction. The used as catalyst in hydroformylation reactions, showing selectivity on the branched aldehyde. High-pressure provides evidence that dinuclear unit is maintained under catalytic conditions.

Reaction of 1-mesitylimidazole with 2-chlorobenzoxazole gave the 2-benzoxazolyl imidazolium salt bzoxcarbH+Cl- (1), which was converted to silver N-heterocyclic carbene complex [AgI(bzoxcarb)Cl] (2) by reaction Ag2O in dichloromethane. The crystal structure analysis confirmed monomeric nature 2. 2 reacted [PdCl2(COD)] yield corresponding palladium [PdCl2(bzoxcarb)] (3), for an X-ray diffraction study established a distorted square planar configuration imidazolyl and oxazolyl ring lying...

A new bis(imidazolylidene) tripodal ligand has been obtained by a simple method. The coordination of this to Rh provides the first Rh(III) complex with bis(carbene) in coordination, and its catalytic properties toward hydrogen transfer have examined.

Two tripodal trisimidazolium ligand precursors have been tested in the synthesis of new N-heterocyclic carbene rhodium and iridium complexes. [Tris(3-methylbenzimidazolium-1-yl)]methane sulfate gave products with coordination decomposed precursor. [1,1,1-Tris(3-butylimidazolium-1-yl)methyl]ethane trichloride (TIMEH(3)(Bu)) coordinated to metal a chelate bridged-chelate form, depending on reaction conditions. The crystal structures two are described. compounds resulting from TIME(Bu) were...

A series of bis-N-heterocyclic carbenes rhodium and iridium have been obtained characterized. The formation the M−C bond has studied according to experimental theoretical data, showing that two different mechanisms are operative for first (single proton deprotonation bisimidazolium salt, or oxidative addition followed by metal hydride) second (oxidative C−H bond, yielding a NHC-IrIII-H species) metalation processes. In case complexes with long linkers between imidazolium rings, reductive...

The carbene-ligand precursors methylenebis(N-alkylimidazolium) iodide (alkyl = methyl, neo-pentyl) and ethylenebis(N-methylimidazolium) chloride have been used in the preparation of several new Ru(II)-p-cymene complexes where ligand behaves as mono- bidentate. molecular structures two biscarbene-complexes are reported. From data reported, we can conclude that steric reasons (mainly bisimidazolium linkers, methylene/ethylene) main factors determining both reactivity synthetic difficulties products

One catalyst fits all! is active for a wide set of benzylating reactions (see scheme). A tandem process allows the use aldehydes and ketones as agents.The compound [IrCp*(OTf)(2)(I(nBu))] (I(nBu)=1,3-di-n-butyl-imidazolylidene) an effective in benzylation arenes with different agents, such alcohols, ethers styrenes, representing unprecedented highly versatile this type process. The same also catalyses remarkable that through base-free hydrogenation C==O bonds iPrOH further resulting primary...

A series of homo- and hetero-dimetallic complexes Ir, Rh, Pd have been obtained using our previously reported Y-shaped tris-NHC ligand. The new can be through the isolation corresponding monometallic intermediates (in which ligand always coordinates in a chelating form) or by one-pot stepwise synthetic protocol that avoids intermediate. catalytic properties Ir–Pd explored two tandem processes: dehalogenation/transfer hydrogenation haloacetophenones Suzuki-coupling/transfer...