RÍOS MORENO , Pablo

El objetivo de esta Tesis Doctoral consiste en el empleo de ligandos con diferentes propiedades estereoelectrónicas y su papel en el diseño de complejos organometálicos capaces de activar moléculas a priori inertes (Capítulo 1), de obtener catalíticamente un único producto de manera selectiva (Capítulos 1 y 4) o de detectar y aislar intermedios...

The ambiguous bonding situation of σ-E−H (E=Si, B) complexes in transition metal compounds has been rationalized by means of Density Functional Theory calculations. To this end, the combination of the Energy Decomposition Analysis (EDA) method and its Natural Orbital for Chemical Valance (NOCV) extension has been applied to representative...

Platinum complexes have been often considered as the least reactive of the group 10 triad metals. Slow kinetics are behind this lack of reactivity but, still, some industrially relevant catalytic process are dominated by platinum compounds and sometimes different selectivities can be found in comparison to Ni or Pd. Nevertheless, during the...

In this Perspective we discuss the ability of transition metal complexes to activate and cleave the Si–H and B–H bonds of hydrosilanes and hydroboranes (tri- and tetra-coordinated) in an electrophilic manner, avoiding the need for the metal centre to undergo two-electron processes (oxidative addition/reductive elimination). A formal...

This work describes a thorough investigation of the mechanism of a highly selective hydrosilylation of CO2 to the formaldehyde level catalyzed by a bis(phosphino)boryl (PBP)Ni(II) complex in the presence of B(C6F5)3. CO2 activation by insertion into the Ni–H bond of the catalyst precursor 2 is shown to occur very easily, because of the trans...

A dinucleating 1,8-naphthyridine ligand featuring fluorene-9,9-diyl-linked phosphino side arms (PNNPFlu) was synthesized and used to obtain the cationic dicopper complexes 2, [(PNNPFlu)Cu2(μ-Ph)][NTf2]; [NTf2] = bis(trifluoromethane)sulfonimide, 6, [(PNNPFlu)Cu2(μ-CCPh)][NTf2], and 3, [(PNNPFlu)Cu2(μ-OtBu)][NTf2]. Complex 3 reacted with...

Selective reduction of CO2 to the formaldehyde level remains an important challenge and to date only a few catalysts have been developed for this reaction. Herein, we report an efficient catalyst that consists of a bis(phosphino)boryl nickel hydride complex in combination with B(C6F5)3, for the highly selective hydrosilation of CO2 to...

The efficient catalytic hydrosilylation of ketones and aldehydes has been investigated using a nickel pincer hydride complex supported by a diphosphino-boryl ligand (PBP). It was found that the presence of the boryl group within the skeleton of the ligand has a beneficial effect on the catalytic activities observed for ketones compared to...

The low-electron-count cationic platinum complex [Pt(ItBu')(ItBu)][BAr], 1, interacts with primary and secondary silanes to form the corresponding σ-SiH complexes. According to DFT calculations, the most stable coordination mode is the uncommon η-SiH. The reaction of 1 with EtSiH leads to the X-ray structurally characterized 14-electron Pt...

Platinum complexes [Pt(NHC')(NHC)][BArF] (NHC' denotes the cyclometallated N-heterocyclic carbene ligand, NHC) react with primary silanes RSiH3 leading to the cyclometallated platinum(II) silyl complexes [Pt(NHC-SiHR')(NHC)][BArF] through a process that involves the formation of C−Si and Pt−Si bonds with concomitant extrusion of H2. Low...

The reaction of tri-coordinated boranes (derived from dioxaborolanes and diazaborolanes) with cyclometalated low-electron count platinum complexes [Pt(NHC')(NHC)][BArF] (NHC=ItBuiPr, IMes, IMes*) led, at low temperature, to the formation of the corresponding σ-BH species. Some of these species have been characterized by X-Ray diffraction...

Platinum(II) complex [Pt(It Bu0 )(It Bu)][BArF 4] (1a) is a highly active and selective catalyst in the dehydrocoupling of amines and silanes at part-per-million catalyst loadings (up to 10 ppm, 0.001 mol%), achieving the highest TON and TOF numbers reported in the literature (up to 1 mmol scale). NMR studies suggest a process taking place...

The concept of metal–ligand cooperation opens new avenues for the design of catalytic systems that may offer alternative reactivity patterns to the existing ones. Investigations of this concept with ligands bearing a boron center in their skeleton established mechanistic pathways for the activation of small molecules in which the boron atom...

The low electron count Pt(II) complexes [Pt(NHC′)(NHC)]- [BArF] (where NHC is a N-heterocyclic carbene ligand and NHC′ its metalated form) react with tertiary hydrogermanes HGeR3 at room temperature to generate the 14-electron platinum(II) germyl derivatives [Pt(GeR3)(NHC)2][BArF]. Low-temperature NMR studies allowed us to detect and...

The low-electron count, air-stable, platinum complexes [Pt(ItBu')(ItBu)][BArF] (C1) (ItBu=1,3-di-tert-butylimidazol-2-ylidene), [Pt(SiPh)3(ItBuiPr)2][BArF] (C2) (ItBuiPr=1-tert-butyl-3-iso-propylimidazol-2-ylidene), [Pt(SiPh)3(ItBuMe)2][BArF] (C3), [Pt(GePh3)(ItBuiPr)2][BArF] (C4), [Pt(GePh)3(ItBuMe)2][BArF] (C5) and [Pt(GeEt)3(ItBuMe)2][BArF]...

A reversible carbon–boron bond formation has been observed in the reaction of the coordinatively unsaturated, cyclometalated, Pt(II) complex [Pt(ItBuiPr′)(ItBuiPr)][BArF], 1, with tricoordinated boranes HBR2. X-ray diffraction studies provided structural snapshots of the sequence of reactions involved in the process. At low temperature, we...

We report the dimerization and oligomerization of ethylene using bis(phosphino)boryl supported Ni(II) complexes as catalyst precursors. By using alkylaluminum(III) compounds or other Lewis acid additives, Ni(II) complexes of the type (RPBP)NiBr (R = tBu or Ph) show activity for the production of butenes and higher olefins. Optimized turnover...