(Butane-1,4-diyl)(trimethylphosphane-κP)[tris(3,5-dimethylpyrazol-1- yl-κN 2)hydroborato]iridium(III)

In the mononuclear title iridium(III) complex, [Ir(C4H8)- (C15H22BN6)(C3H9P)], which is based on the [tris(3,5- dimethylpyrazol-1-yl)hydroborato]iridium moiety, Ir[TpMe2], the IrIII atom is coordinated by a chelating butane-1,4-diyl fragment and a trimethylphosphane ligand in a modestly distorted octahedral coordination environment formed by three facial N, two C and one P atom. The iridium–butane-1,4- diyl ring has an envelope conformation. This ring is disordered because alternately the second or the third C atom of the butane-1,4-diyl fragment function as an envelope flap atom (the occupancy ratio is 1:1). In the crystal, molecules are organized into densely packed columns extending along [101]. Coherence between the molecules is essentially based on van der Waals interactionsFEDER CTQ2010–17476Consolider-Ingenio 2010 CSD2007–00006Junta de Andalucía FQM-119 P09-FQM-483

(Butane-1,4-diyl)(trimethylphosphane-κP)[tris(3,5-dimethylpyrazol-1- yl-κN 2)hydroborato]iridium(III)

In the mononuclear title iridium(III) complex, [Ir(C4H8)- (C15H22BN6)(C3H9P)], which is based on the [tris(3,5- dimethylpyrazol-1-yl)hydroborato]iridium moiety, Ir[TpMe2], the IrIII atom is coordinated by a chelating butane-1,4-diyl fragment and a trimethylphosphane ligand in a modestly distorted octahedral coordination environment formed by three facial N, two C and one P atom. The iridium–butane-1,4- diyl ring has an envelope conformation. This ring is disordered because alternately the second or the third C atom of the butane-1,4-diyl fragment function as an envelope flap atom (the occupancy ratio is 1:1). In the crystal, molecules are organized into densely packed columns extending along [101]. Coherence between the molecules is essentially based on van der Waals interactionsFEDER CTQ2010–17476Consolider-Ingenio 2010 CSD2007–00006Junta de Andalucía FQM-119 P09-FQM-483

Synthesis, structure and reactivity of Pd and Ir complexes based on new lutidine-derived NHC/phosphine mixed pincer ligands

Coordination studies of new lutidine-derived hybrid NHC/phosphine ligands (CNP) to Pd and Ir have been performed. Treatment of the square-planar [Pd(CNP)Cl](AgCl2) complex 2a with KHMDS produces the selective deprotonation at the CH2P arm of the pincer to yield the pyridine-dearomatised complex 3a. A series of cationic [Ir(CNP)(cod)]+ complexes 4 has been prepared by reaction of the imidazolium salts 1 with Ir(acac)(cod). These derivatives exhibit in the solid state, and in solution, a distorted trigonal bipyramidal structure in which the CNP ligands adopt an unusual C(axial)–N(equatorial)–P(equatorial) coordination mode. Reactions of complexes 4 with CO and H2 yield the carbonyl species 5a(Cl) and 6a(Cl), and the dihydrido derivatives 7, respectively. Furthermore, upon reaction of complex 4b(Br) with base, selective deprotonation at the methylene CH2P arms is observed. The, thus formed, deprotonated Ir complex 8b reacts with H2 in a ligand-assisted process leading to the trihydrido complex 9b, which can also be obtained by reaction of 7b(Cl) with H2 in the presence of KOtBu. Finally, the catalytic activity of Ir–CNP complexes in the hydrogenation of ketones has been briefly assessed.CTQ2013-45011-P, CTQ2016-80814-R and CTQ2014 -51912-RE

Electron-rich metal complexes for C02 and CS2 incorporation

The dihapto coordination of two molecules of carbon dioxide to a square-planar MoP2(P-P) fragment (P=monodentate-, P-P=bidentate phosphi- ne ligands) can occur in several ways giving rise to different conformers. Compounds of this type have been prepared and their spectroscopic proper- ties investigated by variable temperature 'H and 31P NMR studies. The for- mation of ethylene complexes related to Mo(C2H4)2(PMe3)4, 6, and the study of their reactivity towards carbon dioxide and carbon disulphide is also described. In particular, compound 6 induces a head-to-tail dimerization of carbon disulphide with formation of a Mo(II)-C$4 linkage, which, in the presence of carbon monoxide, undergoes a symmetric, oxidative rupture, which produces a Mo(0) complex and two molecules of carbon disulphide. The insertion reactions of carbon dioxide and other unsaturated molecules into the nickel-carbon bonds of the nickelacyclopentene complexes 9 have been investigated and different organic products isolated by means of simple or sequential insertion reactions.Ministerio de Educación y CienciaAgencia Nacional de Evaluación y Prospectiv

Synthesis and structural characterization of a binuclear iridium complex with bridging, bidentate N-heterocyclic carbene coordination of 2, 2 ':6 ', 2''-terpyridine

Thermal activation of terpyridine in the presence of an unsaturated Ir(III) fragment stabilized by a hydrotris(pyrazolyl) borate ligand gives rise to mononuclear complex 2 and binuclear 3, in which the polypyridine behaves, respectively, as a mono- or a bi-dentate N-heterocyclic carbene

A Diels–Alder Reaction Triggered by a [4 + 3] Metallacycloaddition

The TpMe2Ir(III) complex 1-OH2 (TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate), which contains a labile molecule of water and an iridium-bonded alkenyl moiety (−C(R)═C(R)–(R=CO2Me)) as part of a benzo-annulated five-membered iridacycle, reacts readily with the conjugated dienes butadiene and 2,3-dimethylbutadiene to afford the corresponding Diels–Alder products. Experimental and DFT studies are in accordance with an initial [4 + 3] cyclometalation reaction between the diene and the five-coordinated 16-electron organometallic fragment 1 (generated from 1-OH2 by facile water dissociation). The reaction can be extended to a related TpIr(III) complex (Tp = hydrotris(pyrazolyl)borate) that also features a labile ligand (i.e., 2-THF).Ministerio de Economía y Competitividad CTQ2014- 51912-REDCJunta de Andalucía FQM-119, P09-FQM-483

Hydrogenation of an iridium-coordinated imidazol-2-ylidene ligand fragment

An iridium complex featuring a metalated lutidine-derived CNP ligand reacts with KOt Bu to yield a dimeric species with the two metal centers bound to the opposite ligands through the CHN arms. Furthermore, reaction with H2 in the presence of KOt Bu of the same iridium derivative results in the hydrogenation of the –CHQCH– imidazolylidene moiety of the complex. NMR spectroscopy monitoring of the latter reaction supports the initial formation of a dihydride iridium complex containing an imidazolylidene ligand fragment that is hydrogenated after prolonged reaction time.Ministerio de Economía y Competitividad de España (MINECO) y fondos FEDER de la Unión Europea-CTQ2015-69568-P, CTQ2016-80814-R y CTQ2016- 81797-RED