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Your search keyword '"Carmen Ramirez de Arellano"' showing total 22 results
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22 results on '"Carmen Ramirez de Arellano"'

1. Experimental and theoretical insights in the alkene–arene intramolecular π-stacking interaction

Author

Valeria Corne, Ariel M. Sarotti, Carmen Ramirez de Arellano, Rolando A. Spanevello, and Alejandra G. Suárez

Subjects
acrylic esters, asymmetric synthesis, biomass, conformational equilibrium, π-stacking interaction, Science, Organic chemistry, QD241-441
Abstract

Chiral acrylic esters derived from biomass were developed as models to have a better insight in the aryl–vinyl π-stacking interactions. Quantum chemical calculations, NMR studies and experimental evidences demonstrated the presence of equilibriums of at least four different conformations: π-stacked and face-to-edge, each of them in an s-cis/s-trans conformation. The results show that the stabilization produced by the π–π interaction makes the π-stacked conformation predominant in solution and this stabilization is slightly affected by the electron density of the aromatic counterpart.

Published
2016
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3. Semisynthetic roxburghin tetramethyl ether

Author

Alex Saez, Carmen Ramirez de Arellano, Noureddine El Aouad, Silvia Rodriguez, Felipe Otalvaro, Diego Cortes, and Jairo Saez

Subjects
Crystallography, QD901-999
Abstract

The title molecule, (E)-2,3′,4,5-tetramethoxystilbene, C18H20O4, is virtually planar. The angle between the two benzene rings is 4.06 (6)°. The intermolecular interactions present in the structure are weak. There are C—H...O hydrogen bonds and C—H...π-electron ring interactions. The molecules are ordered into planes that are parallel to (overline{1}01). The distance between adjacent planes is about 3.3 Å and therefore π–π electron interactions between the aromatic planes are also plausible.

Published
2008
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8. Palladium-Assisted Formation of Carbon−Carbon Bonds. 9. Synthesis of (2-Alkenylaryl)- and Indenylpalladium Complexes

Author

José Vicente, Ralph Bergs, and M. Carmen Ramirez de Arellano, Eloísa Martínez-Viviente, Peter G. Jones, and José-Antonio Abad

Subjects
Inorganic Chemistry, Chemistry, Organic Chemistry, chemistry.chemical_element, Stereoselectivity, Physical and Theoretical Chemistry, Medicinal chemistry, E-Z notation, Palladium
Abstract

(o-Formylaryl)palladium complexes [Pd{C6H(CHO)-6-R3-2,3,4}X(N−N)] [R = OMe; X = Cl; N−N = bpy (2,2‘-bipyridine) (1a), tmeda (N,N,N‘,N‘-tetramethylethylenediamine) (1b). R = H; X = Br; N−N = bpy (2a), tmeda (2b)] react with ylides PhCHPPh3, pyCHPPh3 (py = 2-pyridyl), or ClCHPPh3 to give the (o-alkenylaryl)palladium derivatives [Pd{C6HCHCHPh-6-(OMe)3-2,3,4}Cl(N−N)] [N−N = bpy (3a), N−N = tmeda (3b)], [Pd{C6HCHCHpy-6-(OMe)3-2,3,4}Cl(N−N)] [N−N = bpy (4)], [Pd{C6H(E-CHCHCl)-6-(OMe)3-2,3,4}Cl(tmeda)] (5), or [Pd(C6H4CHCHPh-2)Br(N−N)] [N−N = bpy (6a), N−N = tmeda (6b)]. The compounds 3a, 4, and 6a,b are obtained as mixtures of E and Z isomers, whereas the formation of 3b and 5 is stereoselective (E isomer). The reaction of the (o-acetylaryl)palladium complexes [Pd{C6HC(O)Me-6-(OMe)3-2,3,4}Cl(tmeda)] (7) and [Pd{C6H4(C(O)Me)-2}Br(bpy)] (8) with bases results in the formation of the 3-palladaindan-1-ones [Pd(κ2-{C6HC(O)CH2-6-(OMe)3-2,3,4})(tmeda)] (9) and [Pd(κ2-{C6H4C(O)CH2-2}(bpy)] (10). Complexes 3b and 6a,b r...

Published
2000
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9. Synthesis of imidazo[1,5-c][1,3]benzodiazepines via an aza-Wittig/carbodiimide-mediated annulation process

Author

Alberto Tárraga, David Curiel, Carmen Ramirez de Arellano, and Pedro Molina

Subjects
chemistry.chemical_compound, Annulation, chemistry, Intramolecular force, Organic Chemistry, Drug Discovery, Wittig reaction, Hydantoin, Ring (chemistry), Biochemistry, Medicinal chemistry, Carbodiimide
Abstract

The first synthesis of the imidazo[1,5-c][1,3]benzodiazepine ring system has been carried out by reaction of the iminophosphorane derived from the (Z)-5-(o-azidoarylidene)hydantoin with isocyanates. The isomeric (E)-tributyliminophosphorane undergoes intramolecular aza Wittig reaction to give the imidazo[4,5-b]quinolin-2-one ring.

Published
1997
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11. Synthesis of aryltin(IV) complexes using arylmercury compounds. Synthesis of mixed triaryltin(IV) complexes. Crystal and molecular structure of [SPh)Ph2Cl]

Author

José Vicente, María Teresa Chicote, Peter G. Jones, and Maria del Carmen Ramirez-de-Arellano

Subjects
Azo compound, Ligand, Stereochemistry, Aryl, Organic Chemistry, chemistry.chemical_element, Crystal structure, Bite angle, Biochemistry, Inorganic Chemistry, chemistry.chemical_compound, Trigonal bipyramidal molecular geometry, Crystallography, chemistry, X-ray crystallography, Materials Chemistry, Physical and Theoretical Chemistry, Tin
Abstract

The compound [Sn(2-C 6 H 4 NNPh)Ph 2 Cl] ( 1 ) has been prepared by reaction of [SnPh 2 Cl 2 ] with [Hg(2-C 6 H 4 NNPh) 2 ] (1/1) and of [Sn(2-C 6 H 4 NNPh)PhCl 2 ] with [HgPh 2 ] (1/1). Similarly, [Sn(AzMe)Ph 2 Cl] ( 2 ) (AzMe = 5-Me-2- (NNC 6 H 4 Me-4)C 6 H 3 ) has been obtained by reaction of [SnPh 2 Cl 2 ] with [Hg(AzMe) 2 ] (1/1). Metathetical reactions between 2 and KX (1/1) have been shown to give [Sn(AzMe)Ph 2 X] (X = Br ( 3 ), I ( 4 ), CN ( 5 )]. Compound 2 does not react with NaF but the corresponding fluoro complex [Sn(AzMe)Ph 2 F] ( 6 ) can be made by treating NaF with the complex obtained from the reaction of complex 2 with AgClO 4 . In the crystal compound 1 shows a distorted trigonal bipyramidal coordination around the tin atom. The equatorial positions are occupied by the three carbon atoms of the aryl ligands, with the tin atom lying 0.26 A out of the equatorial plane on the side of the axial chloro atom. The 2-(phenylazo)phenyl ligand forms a five-membered chelate ring with a bite angle CSnN of 70.3(1)°.

Published
1990
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12. Synthesis of mixed diaryltin(<scp>IV</scp>) complexes using an arylmercury compound. Crystal and molecular structure of [Sn (2-C6H4NNPh)(Ph)Cl2]

Author

Giancarlo Pelizzi, José Vicente, María Teresa Chicote, Francesca Vitali, and Maria del Carmen Ramirez-de-Arellano

Subjects
Stereochemistry, Ligand, Aryl, chemistry.chemical_element, General Chemistry, Bite angle, Ring (chemistry), Bond length, chemistry.chemical_compound, Trigonal bipyramidal molecular geometry, Crystallography, chemistry, Molecule, Tin
Abstract

The complex [Sn(2-C6H4NNPh)(Ph)Cl2](1) can be prepared by treating [Sn(Ph)Cl3] with [Hg-(2-C6H4NNPh)2](1:1). The reactions of (1) with NMe4Cl (1 : 1) or excess of KX salts give NMe4[Sn(2-C6H4NNPh)(Ph)Cl3](2) or [Sn(2-C6H4NNPh)(Ph)X2][X = Br (3) or l(4)], respectively. The molecular structure of complex (1) shows a distorted trigonal bipyramidal coordination around the tin atom. The equatorial positions are occupied by both carbon atoms of the aryl ligands and by one of the chloro ligands. The angles in the equatorial plane differ from the 120° ideal value [C–Sn–C 136.2(2)°, Cl-Sn-C 111.4(2) and 106.0(1)°] with the tin atom lying 0.314 A out of the equatorial plane on the side of the axial Cl atom. The 2-(phenylazo) phenyl ligand forms with the tin atom a five-membered ring with a bite angle C–Sn–N of 70.9(2)°. The Cl–Sn bond distances are normal although the axial [2.415(2)A] is longer than the equatorial one [2.351(2)A]. Both C-Sn bond lengths are also normal and similar [2.114(5) and 2.117(5)A]. The N–Sn bond length [2.541(3)A] is longer than others reported. To our knowledge, this is the first mixed diaryltin(IV) complex structurally characterized.

Published
1990
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15. Use of the Cationic Fragments [Ru(?5-C5H5) (MeCN)3]+ and [M(?6-C6H5R)(MeCN)3]+ (M=Os, Ru; R=H, Me) as Ionic Coupling Reagents in the Synthesis of the Clusters [Os4M2(CO)12(?6-C6H5R)], [Os4M(CO)12(?6-C6H6)(Au2dppm)] and [Os5Ru(CO)15(?5-C5H5)(AuPPh3)]*.

Author

Muna R. A. Al-Mandhary, Radchada Buntem, Cheryl L. Doherty, Andrew J. Edwards, John F. Gallagher, Jack Lewis, Chi-Keung Li, Paul R. Raithby, M. Carmen Ramirez de Arellano, and Gregory P. Shields

Abstract

Abstract The clusters [H2Os4M(CO)12eta6-C6H6)] (M=Os, Ru) may be deprotonated to generate anions [Os4M(CO)12eta6-C6H6)]2- which react with [M'eta6-C6H5R) (MeCN)3]2+(M'=Os, Ru; R=H, Me) to give the bicapped tetrahedral clusters [Os4(CO)12MM'eta6-C6H5R)2]. Whereas [Os4(CO)12M2eta6-C6H6)2] (M=Os, Ru) have one Meta6-C6H6) unit in a site connected to three other metals, {3}, and one in a site connected to four other metals, {4}, [Os4(CO)12OsRueta6-C6H6)2] has the Rueta6-C6H6) unit in the {3} site irrespective of whether the Os or Ru anion is capped. Coupling of these anions with Au2dppm yields [Os4M(CO)12eta6-C6H6)(Au2dppm)] (M=Os, Ru), which have the arene ligand in the axial site of a trigonal bipyramid and the digold unit capping two faces. Reduction of [H2Os5(CO)15] with K/Ph2CO and coupling with [Rueta5-C5H5)(MeCN)3]2+yields the monoanion [Os5(CO)15Rueta5-C5H5)]- which reacts with [AuPPh3]+ generating [Os5(CO)15Rueta5-C5H5)(AuPPh3)] with the “Ru(C5H5)” unit in the terminal {3} site. [ABSTRACT FROM AUTHOR]

Published
2005

17. Synthesis of mono- and di-aryltin(IV) complexes containing the ligand 2-(phenylazo)phenyl by use of organomercury compounds

Author

Remedios M. Carreño, María Teresa Chicote, José Vicente, and Maria del Carmen Ramirez-de-Arellano

Subjects
Chemistry, Stereochemistry, Ligand, Organic Chemistry, Xylene, Cationic polymerization, Organomercury Compounds, Biochemistry, Medicinal chemistry, Inorganic Chemistry, Turn (biochemistry), chemistry.chemical_compound, Pyridine, Materials Chemistry, Physical and Theoretical Chemistry
Abstract

Reaction of [Hg(2-C6H4N=NPh)Cl] with SnCl2 (1/1) in refluxing xylene gives the monoaryl complex [Sn(2-C6H4N=NPh)Cl3] (I) and Hg. Complex I reacts with excess of NaBr to give [Sn(2-C6H4N=NPh)Br3] (II) and with HgPh2 (1/1) to give [Sn(2-C6H4N=NPh)(Ph)Cl2] (III), which reacts with 1,10-phenanthroline (phen) to give [Sn(2-C6H4N=NPh)(Ph)Cl2(phen)] (IV); this in turn, reacts with Na[BPh4], to give the cationic complex [Sn(2-C6H4N=NPh)(Ph)Cl(phen)[BPh4] (V). The complex [Sn(2-C6H4N=NPh)2Cl2] reacts with excess of NaBr or KSCN to give the corresponding [Sn(2-C6H4N=NPh)2X2] (X = Br (VI), NCS (VII) complexes, and with AgClO4 to give AgCl and a solution from which, by addition of pyridine (py), the complex [Sn(2-C6H4N=NPh)2(py)2](ClO4)2 (VIII) can be isolated.

Published
1989
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18. Cluster build-up using the [Ru(η5-C5H5)(MeCN)3 ]+ cation; synthesis and structural characterisation of some cyclopentadienyl-substituted hexa- and hepta-nuclear ruthenium carbido clusters

Author

Lewis, Jack, A. Morewood, Catherine, R. Raithby, Paul, and Carmen Ramirez de Arellano, M.

Abstract

The reaction of the dianion [Ru5C(CO)14]2- with 2 equivalents of [Ru(η5-C5H5)(MeCN)3] + afforded two new clusters, the hexanuclear anion [Ru6C(CO)14(η5-C5H 5)]- 1 and the neutral heptanuclear cluster [Ru7C(CO)14(η5-C5H 5)2] 2 in high yields. In a similar reaction the hexanuclear dianion [Ru6C(CO)16]2- may be ‘capped’ by [Ru(η5-C5H5)(MeCN)3] + to afford good yields of both the heptanuclear monoanion [Ru7C(CO)16(η5-C5H 5)]- 3 and the neutral cluster 2. The clusters 1, 2 and 3 have been fully characterised by both spectroscopic and crystallographic methods. The crystal structures show that the metal framework of all three clusters is based on a central Ru6C octahedral core. In 1 one of the core atoms is co-ordinated to an η5-C5H5 ligand, while in 2 an additional Ru(η5-C5H5) group caps one triangular face of the octahedron to give a capped octahedral framework. In 3 the single η5-C5H5 ligand is co-ordinated to the capping Ru atom in the capped octahedral framework.

Published
1997
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19. Use of the monocationic fragment [Ru(η5-C5H5)(MeCN)3]+ as a capping reagent in the synthesis of mixed-metal clusters: synthesis and structural characterisation of [Os3RuH(CO)11(η5-C5H5)] and [Os3Ru2(CO)9(µ3-CO)2(η5-C5H5)2]

Author

Buntem, Radchada, Lewis, Jack, A. Morewood, Catherine, R. Raithby, Paul, Carmen Ramirez de Arellano, M., and P. Shields, Gregory

Abstract

The reaction of the monoanion [Os3H(CO)11]– 1 with 1 equivalent of the cation [Ru(C5H5)(MeCN)3]+ 2, in CH2Cl2, formed the mixed-metal, tetranuclear cluster [Os3RuH(CO)11(η5-C5H5)] 3 in high yield. Subsequent deprotonation of 3 with 1,8-diazabicyclo[5.4.0]undec-7-ene, in CH2Cl2, afforded the anion [Os3Ru(CO)11(η5-C5H5)]– 4, and reaction of 4 with a second equivalent of [Ru(C5H5)(MeCN)3]+ provided the new bis-(cyclopentadienyl) cluster [Os3Ru2(CO)9(µ3-CO)2(η5-C5H5)2] 5 in ca. 80% yield. Alternatively, reduction of [Os3(CO)12] with K/Ph2CO afforded the known cluster dianion [Os3(CO)11]2– 6 which can be treated with 2 equivalents of [Ru(C5H5)(MeCN)3]+ to produce 5 in 75% yield. The clusters 3 and 5 have been fully characterised by both spectroscopic and crystallographic methods. The structure of 3 contains an Os3Ru tetrahedron in which the cyclopentadienyl ligand is co-ordinated to the Ru atom in an η5 terminal mode. The metal framework in 5 is a trigonal bipyramid, but may be viewed as an Os3Ru tetrahedral unit, as in 3, to which a second Ru atom capping an Os2Ru triangular face has been added. Both the cyclopentadienyl ligands remain in η5 terminal bonding sites co-ordinated to the two Ru atoms.

Published
1998
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