PALMA RAMÍREZ , María Del Pilar

La tesis doctoral ha tenido por objeto la síntesis y la caracterización química y espectroscópica de alquil y aril derivados de ni(ii) que contienen trimetilfosfina como coligando y el estudio de su reactividad frente a diversos agentes químicos tales como el monóxido y el dióxido de carbono y diversos isonitrilos. El trabajo realizado se ha...

Monomeric alkoxo complexes of the type [(iPrPCP)M-OR] (M = Ni or Pd; R = Me, Et, CH2CH2OH; iPrPCP = 2,6-bis(diisopropylphosphino)phenyl) react rapidly with CO2 to afford the corresponding alkylcarbonates [(iPrPCP)M-OCOOR]. We have investigated the reactions of these compounds as models for key steps of catalytic synthesis of organic carbonates...

The sequence of reactions ensuing when the 2,6-bis(imino)pyridine Fe(II) dialkyl complexes [Fe(CH2SiMe3)2(BIP)] react with trimethylaluminum is described in detail. The first step is the reduction of the dialkyl to the corresponding monoalkyl complex [Fe(CH 2SiMe3)(BIP)]. In the presence of an excess of trimethylaluminum, these undergo exchange...

The reactions of the pincer hydroxide complexes [(iPrPCP)M(OH)] (M=Ni, Pd) with dimethyl carbonate (DMC), and a set of organic electrophiles including benzaldehyde have been investigated in the context of our ongoing investigation on the synthesis of alkyl carbonates from CO2 and alcohols. The final outcome of such reactions is diverse, but for...

1H NMR studies on ethylene oligomerization catalysed by the neutral monoalkyl complex [Fe(Me)(iPrBIP)] allow direct observation of alkyl iron intermediates as well as reversible ethylene coordination to the metal center, providing for the first time experimental evidence for a coordination-insertion mechanism of iron-catalysed ethylene upgrade...

The reaction of the dialkyliron complex [Fe(CH2SiMe 3)2(MesBIP)] (MesBIP = 2,6-bis((N-mesityl)acetimidoyl)pyridine) with protic acids (HY) of different strengths (Y = C6F5O, CF3CO2, Cl, CF3SO3) invariably leads to the cleavage of both Fe-C bonds, independent of the Fe/HY ratio used (either 1:2 or 1:1), affording the corresponding complexes...

Neophylpalladium complexes of the type [Pd(CH(2)CMe(2)Ph)(N-O)(L)], where N-O is picolinate or a related bidentate, monoanionic ligand (6-methylpyridine-2-carboxylate, quinoline-2-carboxylate, 2-pyridylacetate or pyridine-2-sulfonate) and L is pyridine or a pyridine derivative, efficiently catalyze the oxidation of a range of aliphatic,...

The 1,4-dihydropyridinate complex [(4-BnHBIP)Zn(Bn)], readily available through the highly selective reaction of a 2,6-bis(imino)pyridine ligand with dibenzylzinc, contains two distinct reactive centers. One of them is the σorganometallic benzylzinc moiety, which reacts with weak protic acids (e.g., water and methanol) to release the free...

The first complexes containing imidazolium-2-amidinates as ligands (betaine-type adducts of imidazolium-based carbenes and carbodiimides, NHC-CDI) are reported. Interaction of the sterically hindered betaines ICyCDIDiPP and IMeCDIDiPP [both bearing 2,6-diisopropylphenyl (DiPP) substituents on the terminal N atoms] with Cu(I) acetate affords...

Nickel and palladium methoxides [((iPr)PCP)M-OMe], which contain the (iPr)PCP pincer ligand, decompose upon heating to give products of different kinds. The palladium derivative cleanly gives the dimeric Pd(0) complex [Pd(μ-(iPr)PCHP)]2 ((iPr)PCHP = 2,6-bis(diisopropylphosphinomethyl)phenyl) and formaldehyde. In contrast, decomposition of...

Diorganozinc compounds (ZnR2) with R = CH2Ph or CH2CH[double bond, length as m-dash]CH2 react with 2,6-bisiminopyridines (iPrBIP) to afford thermally stable dihydropyridinate(−1) complexes, and do not react if R = CH2SiMe3 or CH2CMe2Ph. NMR studies reveal that dibenzylzinc binds iPrBIP at −80 °C, yielding the unstable complex...

The betaine adduct of N-heterocyclic carbene and carbodiimide (ICy·(p-tol)NCN) was found to be a very efficient ligand to prepare very small (1–1.3 nm) ruthenium nanoparticles (RuNPs). The coordination of the ligand on the metal surface takes place through the carbodiimide moiety. The resulting RuNPs led to decarbonylation of THF and showed...

Palladium(I) carbonyl carboxylate complexes [Pd(μ-CO)(μ-RCO2)]n (R = Me, n = 4; R = CMe3, n = 6) and the corresponding palladium(II) carboxylates (acetate and pivalate) catalyze the cyclopropanation of olefins with ethyl diazoacetate. The performance of these catalysts is similar in terms of selectivity and cyclopropane yields, regardless of...

Phosphinito-imines, a new class of P,N donors, are readily generated by reaction of bulky arylamide anions [R2CONAr]− (R2 = Me or t-Bu; Ar = 2,6-i-Pr2C6H4) with chlorophosphines ClP(R1)2. In solution, free phosphinito-imines exist in equilibrium with the corresponding amidophosphine tautomers, containing a nitrogen-bound P(R1)2 group. However,...

A family of stable and otherwise selectively unachievable 2,6-bisimino-4-R-1,4-dihydropyridinate aluminium (III) dialkyl complexes [AlR'2(4-R-i PrBIPH)] (R = Bn, Allyl; R' = Me, Et, i Bu) have been synthesized, taking advantage of a method for the preparation of the corresponding 4-R-1,4-dihydropiridine precursors developed in our group. All...