Javier López

Reactions of alkenyl and alkynyl ruthenium(II) complexes with isocyanides: Synthesis of α, β-unsaturated η1-acylruthenium(II) complexes and X-ray structure of [Ru(CCPh)(CN+Bu)3(PPh3)2]PF6

Abstract Reaction of (E)-alkenyl complexes Ru(CO)Cl(CHCHR)(PPh3)2 and Ru(CO)Cl(CHCHR) (PPh3)2L (L  Me2Hpz, py) with an excess of an isocyanide R′NC (R′tBu or cyclohexyl (Cy)) gives (E)-α,β-unsaturated-η1-acyl complexes [Ru(COCHCHR)(CNR′)3(PPh3)2]Cl in good yield. The corresponding reactions with 1 equivalent of isocyanide give the hexacoordinate complexes Ru(CO)Cl(CHCHR)(CNR′)(PPh3)2. The reaction of [Ru(CO)(CHCHR)(NCMe)2(PPh3)2]PF6 with tBuNC also affords η1-acyl complexes [Ru(COCHCHR)(CNtBu)3(PPh3)2]PF6. On the other hand, treatment of alkynyl complexes [Ru(CO)(CCR)(py)2(PPh3)2]PF6 with an excess of tBuNC under forcing conditions promotes substitution of CO and pyridine ligands by the isocyanide, yielding alkynyl derivatives [Ru(CCR)CNtBu)3(PPh3)2]PF6. An X-ray diffraction study of one of the complexes (R  Ph) confirmed the proposed structure. Similarly, reaction of the alkynyl complexes with CO gives only the ligand-substitution products [Ru(CO)2(CCR)(py)(PPh3)2][PF6]. The reaction of (E)-alkenyl ruthenium(II) complexes with alkyl isocyanides proceeds under mild conditions to yield (E)-α,β-unsaturated-η1-acyl ruthenium(II) complexes. Although these complexes are obtained from intermediates with both CO and isocyanide ligands, exclusive migratory insertion of the alkenyl ligand into the RuCO bond is observed. The related alkynyl carbonyl ruthenium(II) complexes do not undergo insertion, reacting sluggishly with the isocyanides to yield new alkynyl ruthenium complexes in which the carbonyl ligand has been replaced by an isocyanide ligand. The corresponding reaction with CO leads to dicarbonyl alkynyl complexes by substitution of the pyridine trans to the alkynyl ligand.

Reactions of cationic hydrido complexes [Ru(CO)H(MeCN)2(PPh3)2]A (A ClO4, PF6) with alkynes. The crystal structure of [Ru(CO) (MeOOCCCHCOOMe) (MeCN)2(PPh3)2]ClO4

Abstract Reactions of [Ru(CO)H(MeCN)2(PPh3)2]A with mono- and di-substituted acetylenes give the alkenyl derivatives [Ru(CO)(RCCHR′)(MeCN)2(PPh3)2]A (A  ClO4, R  H; R′  C3H7, CMe3, Ph, COOMe; R  R′  COOMe; A  PF6, R  R′  Ph) resulting from a cis-insertion of the alkyne into the RuH bond. The reaction of the perchlorate complex with diphenylacetylene yields alkenyl chlororuthenium derivatives resulting from the unexpected reduction of the perchlorate anion to chloride. The crystal structure of [Ru(CO)(MeOOCCCHCOOMe)(MeCN)2(PPh3)2]ClO4 has been determined by X-ray crystallography (orthorhombic, P212121, a 14.498(1), b 15.080(1), c 22.677(2) A). In this cationic complex both phosphine and acetonitrile molecules and, consequently, the carbonyl and alkenyl ligands are mutually trans, whereas in the other complexes only the phosphine ligands are in trans disposition, as inferred from 1H NMR spectroscopic data.

Bis-insertion reactions of Ru(CO)HCl(PPh3)3 with methyl propiolate. The unexpected formation of (methoxycarbonylethenyl)triphenylphosphonium chloride

Abstract The reaction of Ru(CO)HCl(PPh 3 ) 3 with methyl propiolate gives two bis-insertion derivatives resulting from a head-to-head dimerization reaction. The eliminated triphenylphosphine ligand reacts with the alkyne to give an actylidephosphonium salt, which brings about substitution of the chloride ligand of Ru(CO)Cl(CHCHCOOMe)(PPh 3 ) 2 by acetylide. The resulting phosphonium salt, methoxycarbonylethenyltriphenylphosphonium chloride has been characterized as the methanol adduct 2-methoxy-2-methoxycarbonylethyltriphenylphosphonium chloride.

Motion planning for a novel reconfigurable parallel manipulator with lockable revolute joints

This paper introduces a class of reconfigurable parallel robots consisting of a fixed base and a moving platform connected by serial chains having RRP̲S (Revolute-Revolute-Prismatic-Spherical) topology. Only the prismatic joint is actuated and the first revolute joint in the chain can be locked or released online. The introduction of these lockable joints allow the prismatic actuators to maneuver to approximate 6-DoF motions for the moving platform. An algorithm for generating these maneuvers is first described. Then, a motion planner, based on the generation of a Probabilistic RoadMap (PRM) whose nodes are connected using the described maneuvers, is presented. The generated trajectories avoid singularities and possible collisions between legs. (See accompanying video)

Synthesis of RuII hydride and alkenyl amidine complexes. The crystal structure of [Ru(CO)(CH=CHCMe3){NH=C(Me)(Me2pz)}(PPh3)2]PF6

Abstract The reaction of the ruthenium hydrides [Ru(CO)H(R 1 CN) 2 (PPh 3 ) 2 ]A (A = ClO 4 or PF 6 ) (R 1 = Me or CH 2 Ph) or the alkenyl derivatives [Ru(CO)(CH=CHR 1 ()R 2 CN) 2 )(PPh 3 ) 2 ]PF 6 (R 1 = CMe 3 , Ph; R 2 = Me or CH 2 Ph) with pyrazole or 3,5-dimethylpyrazole gives the ruthenium(II) pyrazolylamidine complexes [Ru(CO)H{NH=C(R 1 )(het)}(PPh 3 ) 2 ]A or [Ru(CO)(CH=CHCR 1 ){NH—C-(R 2 )(het)}(PPh 3 ) 2 ]A, respectively (het = pz or Me 2 pz). The stereochemistry of the resulting complexes has been determined by NOEDIFF experiments and by the X-ray structure determination of [Ru(CO)(CH=CHCMe 3 ){NH=C(Me)(Me 2 pz)}(PPh 3 ) 2 ]PF 6 .

Warm molecular gas temperature distribution in six local infrared bright Seyfert galaxies

We simultaneously analyze the spectral line energy distributions (SLEDs) of CO and H2 of six local luminous infrared (IR) Seyfert galaxies. For the CO SLEDs, we used new Herschel/SPIRE FTS data (from J=4-3 to J=13-12) and ground-based observations for the lower-J CO transitions. The H2 SLEDs were constructed using archival mid-IR Spitzer/IRS and near-IR VLT/SINFONI data for the rotational and ro-vibrational H2 transitions, respectively. In total, the SLEDs contain 26 transitions with upper level energies between 5 and 15000 K. A single, constant density, model (n

Understanding the two-dimensional ionization structure in luminous infrared galaxies

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Star-formation histories of local luminous infrared galaxies

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Reactions of Ru(CO)ClH(C5H5N)(PPh3)2 with 1-alkynes

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VLT-SINFONI sub-kpc study of the star formation in local LIRGs and ULIRGs

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