Elena Pinilla - Academia.edu (original) (raw)
Papers by Elena Pinilla
Molecules, 2007
2-(2,4-Dimethylphenyl)-2H-benzotriazole (1) has been synthesized in a three step procedure starti... more 2-(2,4-Dimethylphenyl)-2H-benzotriazole (1) has been synthesized in a three step procedure starting from 2,4-dimethyl-N-(2-nitrophenyl)benzamide via a 5-(2,4dimethylphenyl)-1-(2-nitrophenyl)-1H-tetrazole intermediate. Its structure and those of Tinuvin ® P and 2-phenyl-2H-benzotriazole (5) have been studied by multinuclear NMR ( 1 H-, 13 C-and 15 N-) in solution and in the solid state. X-ray diffraction analysis of 1 and 5 allowed to us establish the molecular conformation around the single bond connecting the two aromatic systems, in agreement with the conclusions drawn from the NMR study. In the case of 1 ab initio geometry optimization was achieved at the Hartree-Fock HF/6-31G** and DFT B3LYP/6-31G** levels.
Organometallics, 2003
... María A. Garralda,* Ricardo Hernández, Lourdes Ibarlucea, Elena Pinilla,* and M. Rosa... more ... María A. Garralda,* Ricardo Hernández, Lourdes Ibarlucea, Elena Pinilla,* and M. Rosario Torres . Facultad ... f) El Mail, R.; Garralda, MA; Hernández, R.; Ibarlucea, L.; Pinilla, E.; Torres, MR Organometallics2000, 19, 5310. ...
![Research paper thumbnail of Solid-State and Solution Structural Studies of 4-{[C(E)]-1HAzol1-ylimino)methyl}pyridin-3-ols](https://attachments.academia-assets.com/47655075/thumbnails/1.jpg)
](Helvetica Chimica Acta, 2006
The new N-salicylideneheteroarenamines 1–4 were prepared by reacting the biologically relevant 3-... more The new N-salicylideneheteroarenamines 1–4 were prepared by reacting the biologically relevant 3-hydroxy-4-pyridinecarboxaldehyde (5) with 1H-imidazol-1-amine (6), 1H-pyrazol-1-amine (7), 1H-1,2,4-triazol-1-amine (8), and 1H-1,3,4-triazol-1-amine (9). Solution 1H-, 13C-, and 15N-NMR were used to establish that the hydroxyimino form A is the predominant tautomer. A combination of 13C- and 15N-CPMAS-NMR with X-ray crystallographic studies confirms that the same form is present in the solid state. The stabilities and H-bond geometries of the different forms, tautomers and rotamers, are discussed by using B3LYP/6-31G** calculations.
New Journal of Chemistry, 2009
The structures of four NH-pyrazoles, (E)-3,5-bis[b-(4-hydroxy-3-methoxyphenyl)-ethenyl]-1Hpyrazol... more The structures of four NH-pyrazoles, (E)-3,5-bis[b-(4-hydroxy-3-methoxyphenyl)-ethenyl]-1Hpyrazole (3), (E)-3(5)-[b-(4-hydroxy-3-methoxyphenyl)-ethenyl]-5(3)-methyl-1H-pyrazole , , have been determined by X-ray crystallography. Compounds that have a phenol residue crystallize forming sheets that are stabilized by a complex pattern of hydrogen bonds between a unique tautomer (4), or by a 2 : 1 mixture of both tautomers (5) (these tautomers being identical in the case of 3). Pyrazole 8, which lacks OH groups, crystallizes in cyclic dimers that are stabilized by N-HÁ Á ÁN hydrogen bonds. The tautomerism in solution and in the solid state was determined by 13 C and 15 N CPMAS NMR spectroscopy. For compounds 4, 5 and 8, the solid state results agree with those observed by crystallography; the most abundant tautomer in solution coincides with the tautomer present in the solid state (4 and 8) or with the most abundant tautomer in the crystal . , 33, 125-135 | 125 PAPER www.rsc.org/njc | New Journal of Chemistry a The coupling constants were, on average: 3 J H3-H4 = 8.0 Hz, 4 J H4-H6 = 2.0 Hz (not always observed) and 3 J H7-H8 trans = 16.5 Hz.
Helvetica Chimica Acta, 2004
Compounds [{Au(pz)(PPh3)}2] (pz=3,5-disubstituted pyrazolato; R=BuOC6H4 (bp), 1; R=C8H17OC6H4 (op... more Compounds [{Au(pz)(PPh3)}2] (pz=3,5-disubstituted pyrazolato; R=BuOC6H4 (bp), 1; R=C8H17OC6H4 (op), 2; R=C6H13OC6H4 (hp), 3) were easily obtained by reaction of [Au(NO3)(PPh3)] and the corresponding pyrazolato ligand. They exhibit similar NMR patterns, their ESI-MS or FAB-MS data being in agreement with a monomeric molecular formulation [Au(pz)(PPh3)]. By contrast, 1 crystallizes as the dimer [{Au(pz)(PPh3)}2] and exhibits aurophilic Au ⋅⋅⋅Au contacts, while crystallization of 2 in CH2Cl2/hexane gives rise to compound 4, [Au(pz)(PPh3)]⋅(Hpz). The X-ray structure of 4 was solved, showing a H-bond interaction between the monomer of 2 and Hpz. Reactions between [{Au(pz)(PPh3)}2] and their corresponding 1H-pyrazole (Hpz) were also explored. Compounds 1–3 exhibit luminescence in the solid state. Their emission spectra are reported and analyzed.
Inorganic Chemistry, 2005
New hydridoirida-beta-diketones [IrH[(PPh2(o-C6H4CO))2H](CO)]ClO4 2 and [IrH[(PPh2(o-C6H4CO))2H](... more New hydridoirida-beta-diketones [IrH[(PPh2(o-C6H4CO))2H](CO)]ClO4 2 and [IrH[(PPh2(o-C6H4CO))2H](olefin)]BF4 (olefin = C2H4, 5; 1-hexene, 10) have been prepared. These complexes may afford new diacylhydridoiridium(III) derivatives. In chloroform solution, complex 2 is in equilibrium with the deprotonated diacylhydride trans-[IrH(PPh2(o-C6H4CO))2(CO)] complex 3. In DMSO, deprotonation of 2 occurs to yield the kinetically favored product 3, which isomerizes to the thermodynamically favored complex cis-[IrH(PPh2(o-C6H4CO))2(CO)] 4. Reprotonation of 4 with HBF4 in chlorinated solvents gives the cation in 2. In coordinating solvents such as dimethyl sulfoxide or acetonitrile, complex 5 undergoes displacement of ethylene to afford [IrH{(PPh2(o-C6H4CO))2H](L)]BF4 (L = DMSO, 7; CH3CN, 9). Complexes 5 and 7 undergo deprotonation by NEt3 to give the corresponding diacylhydrides. The ethylene complex gives only trans-[IrH(PPh2(o-C6H4CO))2(C2H4)] 6, while the dimethyl sulfoxide derivative affords a mixture of trans- and cis-[IrH(PPh2(o-C6H4CO))2(DMSO)] 8. Complex 10 shows inhibited alkene rotation around the Ir-olefin axis. All of the complexes were fully characterized spectroscopically. Single-crystal X-ray diffraction analysis was performed on complexes 3, 4, and 9. The 13C NMR and X-ray data point to a carbenoid character in the carbon atoms bonded to iridium in the irida--diketone fragment, so that it can be considered as an acyl(hydroxycarbene) moiety.
Organometallics, 2007
RhCl(COD)] 2 (COD ) 1,5-cyclooctadiene) reacts with o-(diphenylphosphino)benzaldehyde (PPh 2 -(o-... more RhCl(COD)] 2 (COD ) 1,5-cyclooctadiene) reacts with o-(diphenylphosphino)benzaldehyde (PPh 2 -(o-C 6 H 4 CHO)) (Rh/P ) 1:1) in the presence of pyridine to give an acyl hydrido species, [RhHCl(PPh 2 -(o-C 6 H 4 CO))(py) 2 ] (1). In chlorinated solvents exchange of hydride by chloride gives [RhCl 2 (PPh 2 (o-C 6 H 4 CO))(py) 2 ] (2). The reactions of 1 with PPh 3 and of 2 with biacetyl dihydrazone (bdh) gives the pyridine substitution products [RhHCl(PPh 2 (o-C 6 H 4 CO))(PPh 3 )(py)] (4) and [RhCl 2 (PPh 2 (o-C 6 H 4 CO))-(bdh)] (3), respectively. By using a 1:2 ratio of Rh to PPh 2 (o-C 6 H 4 CHO) [RhHCl(PPh 2 (o-C 6 H 4 CO))(κ 1 -PPh 2 (o-C 6 H 4 CHO))(py)] (5) with trans phosphorus atoms is formed. The aldehyde group may undergo two different reactions. In benzene 5 affords the acyl hydroxyalkyl species [RhCl(PPh 2 (o-C 6 H 4 CO))-(PPh 2 (o-C 6 H 4 CHOH))(py)] (6) with cis phosphorus atoms, via a pyridine dissociation path. 6 undergoes dehydrogenation, with H 2 evolution, to afford the diacyl derivative [RhCl(PPh 2 (o-C 6 H 4 CO)) 2 (py)] (8), which shows fluxional behavior in solution, with the values ∆H q ) 8.8 ( 0.4 kcal mol -1 and ∆S q ) -16.7 ( 1 eu. Opening of the acylphosphine chelate appears to be responsible for the fluxionality. In methanol 5 undergoes displacement of chloride by the aldehyde to afford the cationic acyl hydrido aldehyde [RhH(PPh 2 (o-C 6 H 4 CO))(κ 2 -PPh 2 (o-C 6 H 4 CHO))(py)] + (10), which can be isolated if precipitated immediately with an appropriate counterion. Longer reaction periods of 5 in methanol solution lead to a mixture of the diacyl 8 and the cationic acyl hydrido alcohol [RhH(PPh 2 (o-C 6 H 4 CO))(κ 2 -PPh 2 (o-C 6 H 4 -CH 2 OH))(py)] + (11). The spectroscopic characterization of some intermediates in this reaction evidence a bimolecular ionic mechanism as being responsible for the hydrogenation of the aldehyde with the hydroxyalkyl 6 being the source of both proton and hydride. Complex 11 can also be obtained by the reaction of 5 with NaBH 4 in methanol solution.
Supramolecular Chemistry, 2006
... DOI: 10.1080/10610270600594865 Rosa M. Claramunt a * , Pilar Cornago a , M. Dolores Santa Mar... more ... DOI: 10.1080/10610270600594865 Rosa M. Claramunt a * , Pilar Cornago a , M. Dolores Santa María a , Verónica Torres a , Elena Pinilla b , M. Rosario Torres b & José Elguero c pages 349-356. Available online: 04 Mar 2011. ...
![Research paper thumbnail of Silver and Gold Trinuclear Complexes Based on 3-Substituted or 3,5-Disubstituted Pyrazolato Ligands. X-Ray Crystal Structure ofcyclo-Tris{μ-[3,5-bis(4-phenoxyphenyl)-1H-pyrazolato-κN1 : κN2]}trigold Dichloromethane ([Au(μ-)]3⋅CH2Cl2](https://attachments.academia-assets.com/47655104/thumbnails/1.jpg)
](Helvetica Chimica Acta, 2004
Ten new silver and gold trimeric complexes of the type [M3(μ-pz′)3] (M=Au, Ag), where pz′ indicat... more Ten new silver and gold trimeric complexes of the type [M3(μ-pz′)3] (M=Au, Ag), where pz′ indicate pyrazolato ligands derived from mesogenic 3,5-disubstituted 1H-pyrazoles or non-mesogenic 3-substituted 1H-pyrazoles HpzR (R=C6H4OCnH2n+1), were synthesized and characterized. The gold and silver complexes 7, 8, 10, and 11 containing symmetric pyrazolato ligands as bridging groups (; R=C6H4OCnH2n+1, n=4 () and 8 ()) exhibited a trigonal symmetric structure. The same results were obtained for the related silver derivatives 16–18 with 3-substituted pyrazolato ligands (pzR; R=C6H4OCnH2n+1, n=4 (pzbp), 12 (pzddp), and 18 (pzodp)). By contrast the 3-substituted pyrazolato-gold compounds 13–15 adopted an asymmetric molecular structure related to the position of the substituents on the trinuclear core. The thermal behavior of these complexes was investigated by differential scanning calorimetry and polarized-light microscopy. The mesomorphism of the parent 3,5-disubstituted pyrazoles is avoided in their corresponding trinuclear complexes 7, 8, 10, and 11. However, the metal derivatives 14 and 17 containing the asymmetric 3-[4-(dodecyloxy)phenyl]pyrazolato ligand were found to have liquid-crystal properties. These compounds exhibited monotropic behavior with columnar mesophases that could be related to the disc-like shape of the molecular core and the appropriate length of the alkyloxy chain. For comparative purposes, the X-ray structure of the related gold complex [Au3(μ-)3] (9) having phenoxyphenyl substituents at the 3- and 5-positions of the pyrazolato ligand is also described. The molecular structure is formed by a non-planar (AuNN)3 core, containing three Au-atoms bridged by three pyrazolato ligands. The molecular packing is described as a columnar organization, the shortest Au ⋅⋅⋅Au distance being 4.639(1) Å between consecutive trimers.
Helvetica Chimica Acta, 2002
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European Journal of Inorganic Chemistry, 2006
The hydridoirida-β-diketone [IrH{[PPh2(o-C6H4CO)]2H}Cl] (1) reacts with silver salts of potential... more The hydridoirida-β-diketone [IrH{[PPh2(o-C6H4CO)]2H}Cl] (1) reacts with silver salts of potentially coordinating anions such as tosylate (–OTs) or triflate (–OTf) to afford the mononuclear neutral derivatives [IrH{[PPh2(o-C6H4CO)]2H}(X)] [X = OTs (2), OTf (3)]. In acetone solution the triflate anion in 3 is displaced by the solvent to afford the cationic complex [IrH{[PPh2(o-C6H4CO)]2H}(acetone)]OTf (4), which is stable only in acetone solution. The reaction of 1 with halide scavengers containing less coordinating anions such as PF6– or BF4– results in the formation of cationic compounds [{IrH[{PPh2(o-C6H4CO)}2H]}2(μ-Cl)]A [A = BF4 (5), PF6 (6)] containing a dinuclear species with a single chlorine atom bridging two hydridoirida-β-diketone fragments. Both fragments are magnetically non-equivalent and the acylphosphane groups in each hydridoirida-β-diketone fragment are chemically equivalent. This species undergoes a fluxional process in solution, with ΔH‡ = 7.8 ± 0.4 kcal mol–1 and ΔS‡ = –10.9 ± 0.5 eu. A combination of rotation around the Ir–Cl bonds and variation of the Ir–Cl–Ir angle is suggested to be responsible for the fluxionality. Complex 5 reacts further with AgBF4 to undergo chloride abstraction along with hydrogen loss and deprotonation to give the cationic dinuclear complex [Ir2H{PPh2(o-C6H4CO)}{μ-PPh2(o-C6H4CO)}3]BF4 (7), which contains an acylphosphane chelate along with three acylphosphane bridging ligands and a single hydrido ligand. Bubbling of HCl through an MeOH solution of 7 gives 1, thus making the loss of hydride, enolic protons and chloride from complex 1 a reversible process. All the complexes were fully characterized spectroscopically. Single-crystal X-ray diffraction analysis was performed on complexes 5 and 7. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Dalton Transactions, 2008
The hydridoirida-beta-diketone [IrHCl{(PPh2(o-C6H4CO))2H}] (1a) reacts with bases such as KOH or ... more The hydridoirida-beta-diketone [IrHCl{(PPh2(o-C6H4CO))2H}] (1a) reacts with bases such as KOH or NaHCO3 in methanol to undergo dehydrodechlorination and acyl-bridge formation affording [Ir2H2(PPh2(o-C6H4CO))2(mu-PPh2(o-C6H4CO))2] (2) with two acylphosphine chelate-bridging ligands, in a head-to-tail disposition, and terminal hydrides. The acyl bridges can be broken by pyridine, PPh3, CO or dimethylsulfoxide affording selectively mononuclear diacylhydrido neutral derivatives [IrH(PPh2(o-C6H4CO))2L] (3-6). la reacts with KOH or NaHCO3 in refluxing methanol to afford a novel dihydridoirida-beta-diketone [IrH2{(PPh2(o-C6H4CO))2H}](7), via dehydrodechlorination to afford 2, which then undergoes hydrogenation and protonation. The reaction of la with NEt3 affords 2 and [NHEt3]Cl. Further reaction affords [Ir2(mu-H){mu-PPh2(o-C6H4CO)}2(PPh2(o-C6H4CO))2] (8), with two acylphosphine chelate-bridging ligands and a bridging hydride. Neutral or cationic hydridoirida-beta-diketone complexes react with [Rh(cod)(OMe)]2 (cod = 1,5-cyclooctadiene) to afford hydridoirida-P-diketonaterhodium(I) complexes [IrHCl(mu-PPh2(o-C6H4CO))2Rh(cod)] (9) or [IrHL(mu-PPh2(o-C6H4CO))2Rh(cod)]ClO4 (L = py, 10; CO, 11), respectively that isomerise to the thermodynamically stable isomers of [IrCl(PPh2(o-C6H4CO))(mu-H))(mu-PPh,2(o-C6H4CO))Rh(cod)] (12) or [Ir(py)(PPh2(o-C6H4CO))(mu-H))(mu-PPh2(o-C6H4CO))Rh(cod)]ClO4(13). The reaction of 7 with [Rh(cod)(OMe)]2 affords [Ir(PPh2(o-C6H4CO))2(mu-H)2Rh(cod)](14). All the complexes were fully characterised spectroscopically. Single-crystal X-ray diffraction analysis was performed on 2, 4, 7, [8]ClO4 and 9.
Crystal Growth & Design, 2007
Solid-state reactions of 3, 5-dimethyl-1 H-pyrazole (dmpz) and salicylic acid (sa) in different s... more Solid-state reactions of 3, 5-dimethyl-1 H-pyrazole (dmpz) and salicylic acid (sa) in different stoichiometries afford two different trimers whose structures have been determined by X-ray diffraction and analyzed by 13C and 15N solid-state nuclear magnetic resonance ...
Journal of Organometallic Chemistry, 1996
Solution studies by 1H and 13C NMR and IR spectroscopy of rhodium(I) complexes TpPhRh(NBD) 1, TpP... more Solution studies by 1H and 13C NMR and IR spectroscopy of rhodium(I) complexes TpPhRh(NBD) 1, TpPhRh(COD) 2 and TpPhRd(CO)23 (NBD = 2,5-norbornadiene, COD = 1,5-cyclooctadiene) show that these compounds exist as mixtures of two isomeric square-planar complexes containing the TpPh ligand in a bidentate k2-bonded form, with the third uncoordinated pyrazolyl ring occupying an equatorial position, form A, or an axial position, form B. In the solid state the complexes are tetracoordinated, as proved by X-ray crystallography: 1 (monoclinic, space group P21/c) and 2 (orthorhombic, space group P212121), whose structures correspond to forms B and A respectively. Changes in the A/B ratio in the solid complex TpPhRh(CO)23 were observed after several months.
Journal of Materials Chemistry, 1999
The organometallic compounds [4-O 2 NC 6 H 3 (2-CH 3 )NLNC 6 H 3 (5∞-CH 3 )-2∞-(g5-C 5 H 4 )Fe(g5... more The organometallic compounds [4-O 2 NC 6 H 3 (2-CH 3 )NLNC 6 H 3 (5∞-CH 3 )-2∞-(g5-C 5 H 4 )Fe(g5-C 5 H 5 )] 1 and ... [Mo(Cl)(TpAn)(NO){NHC 6 H 3 (3-CH 3 )[NLNC 6 H 3 (5-CH 3 )-2-(g5-C 5 H 4 )Fe(g5-C 5 H 5 )]-4}] 2 {TpAn=hydrotris[3-
Inorganic Chemistry Communications, 2002
A new family of linear Pd(II) complexes based on pyrazoles containing long-chain substituents at ... more A new family of linear Pd(II) complexes based on pyrazoles containing long-chain substituents at the third position has been prepared and their mesomorphic properties studied. The crystalline structure of one of these compounds is described as a representative example of a very elongated and straight molecule.
European Journal of Inorganic Chemistry, 2004
New AuI/AgI complexes containing one or two substituted pyrazole ligands [Au(Hpzbp2)(PPh3)](p-CH3... more New AuI/AgI complexes containing one or two substituted pyrazole ligands [Au(Hpzbp2)(PPh3)](p-CH3C6H4SO3) [Hpzbp2 = 3,5-bis(4-n-butoxyphenyl)pyrazole] (1) and [M(HpzR2)2]nX [HpzR2 = Hpzbp2, M = Au, n = 1, X = p-CH3C6H4SO3 (2), NO3− (3); n = 2, X = 1,5-naphthalenedisulfonate (1,5nds) (4); HpzR2 = Hpzbp2, M = Ag, n = 1, X = BF4− (5), CF3SO3− (6); HpzR2 = HpzNO2 (3,5-dimethyl-4-nitropyrazole), M = Ag, n = 1, X = BF4− (7), CF3SO3− (8)], have been prepared and characterized. Compounds 1, 2, 5 and 8 have been proved to be useful for supramolecular assembly from their single X-ray diffraction analysis. In all cases strong hydrogen bonds maintain the cationic units bonded to their corresponding counterions. The crystal packing arrangement of 1, 2 and 5 is, however, determined by weak C−H···O/F hydrogen-bonding interactions involving the remaining O/F atoms of the counterion. By contrast, for 8 a two-dimensional layer-type polymeric network is formed by π···π (NO2···NO2) and coordinative Ag···O interactions in which the NO2 substituent on the pyrazole is implicated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
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Helvetica Chimica Acta, 2001
Copper(II) complexes containing β-diketonato ligands of the general formula [Cu{(4-RO)C 6 H 4 COC... more Copper(II) complexes containing β-diketonato ligands of the general formula [Cu{(4-RO)C 6 H 4 COCHCOC 6 H 4 (4-OR)} 2 ] 3 (R=Bu) or 4 (R=Ph) were prepared and their structures solved by X-ray diffraction. The crystal structure of the parent ligand (4-BuO)C 6 H 4 COCH 2 ...
Journal of The Less Common Metals, 1980
The preparation, properties and catalytic activity of new cationic rhodium(I) complexes of the ge... more The preparation, properties and catalytic activity of new cationic rhodium(I) complexes of the general formulae [ Rh(NBD)Ls] C104 and [Rh(NBD)L(PRs)]
European Journal of Inorganic Chemistry, 2003
The 3,5-bis(4-butoxyphenyl)pyrazolyl group (Pzbp2) has been used as a building block for mono- an... more The 3,5-bis(4-butoxyphenyl)pyrazolyl group (Pzbp2) has been used as a building block for mono- and polymetallic derivatives of 2,4,6-tris[3,5-bis(4-butoxyphenyl)pyrazol-1-yl]-1,3,5-triazine (TPzbp2Tz, 1), 2-[3,5-bis(4-butoxyphenyl)pyrazol-1-yl]pyridine (Pzbp2Py, 2), and 3,5-bis(4-butoxyphenyl)pyrazole (HPzbp2, 3) ligands. The synthesis and characterisation of the new hexadentate ligand 1 are described, together with the chemistry of its metal complexes containing [Pd(η3-C3H5)]+ and [Au(PPh3)]+ fragments. The related complexes containing Pzbp2Py (2) were also studied and their structural characteristics were compared to those of the TPzbp2Tz species. The role of the counter-ion on the supramolecular assembly of complexes containing the HPzbp2 ligand 3 was made clear by the X-ray structures of [Pd(η3-C3H5)(HPzbp2)2](BF4) and [Au(HPzbp2)(PPh3)](NO3). Hydrogen bonds and/or bonding interactions are responsible for pseudohelical one-dimensional polymers or supramolecular columnar arrays, respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Molecules, 2007
2-(2,4-Dimethylphenyl)-2H-benzotriazole (1) has been synthesized in a three step procedure starti... more 2-(2,4-Dimethylphenyl)-2H-benzotriazole (1) has been synthesized in a three step procedure starting from 2,4-dimethyl-N-(2-nitrophenyl)benzamide via a 5-(2,4dimethylphenyl)-1-(2-nitrophenyl)-1H-tetrazole intermediate. Its structure and those of Tinuvin ® P and 2-phenyl-2H-benzotriazole (5) have been studied by multinuclear NMR ( 1 H-, 13 C-and 15 N-) in solution and in the solid state. X-ray diffraction analysis of 1 and 5 allowed to us establish the molecular conformation around the single bond connecting the two aromatic systems, in agreement with the conclusions drawn from the NMR study. In the case of 1 ab initio geometry optimization was achieved at the Hartree-Fock HF/6-31G** and DFT B3LYP/6-31G** levels.
Organometallics, 2003
... María A. Garralda,* Ricardo Hernández, Lourdes Ibarlucea, Elena Pinilla,* and M. Rosa... more ... María A. Garralda,* Ricardo Hernández, Lourdes Ibarlucea, Elena Pinilla,* and M. Rosario Torres . Facultad ... f) El Mail, R.; Garralda, MA; Hernández, R.; Ibarlucea, L.; Pinilla, E.; Torres, MR Organometallics2000, 19, 5310. ...
Helvetica Chimica Acta, 2006
The new N-salicylideneheteroarenamines 1–4 were prepared by reacting the biologically relevant 3-... more The new N-salicylideneheteroarenamines 1–4 were prepared by reacting the biologically relevant 3-hydroxy-4-pyridinecarboxaldehyde (5) with 1H-imidazol-1-amine (6), 1H-pyrazol-1-amine (7), 1H-1,2,4-triazol-1-amine (8), and 1H-1,3,4-triazol-1-amine (9). Solution 1H-, 13C-, and 15N-NMR were used to establish that the hydroxyimino form A is the predominant tautomer. A combination of 13C- and 15N-CPMAS-NMR with X-ray crystallographic studies confirms that the same form is present in the solid state. The stabilities and H-bond geometries of the different forms, tautomers and rotamers, are discussed by using B3LYP/6-31G** calculations.
New Journal of Chemistry, 2009
The structures of four NH-pyrazoles, (E)-3,5-bis[b-(4-hydroxy-3-methoxyphenyl)-ethenyl]-1Hpyrazol... more The structures of four NH-pyrazoles, (E)-3,5-bis[b-(4-hydroxy-3-methoxyphenyl)-ethenyl]-1Hpyrazole (3), (E)-3(5)-[b-(4-hydroxy-3-methoxyphenyl)-ethenyl]-5(3)-methyl-1H-pyrazole , , have been determined by X-ray crystallography. Compounds that have a phenol residue crystallize forming sheets that are stabilized by a complex pattern of hydrogen bonds between a unique tautomer (4), or by a 2 : 1 mixture of both tautomers (5) (these tautomers being identical in the case of 3). Pyrazole 8, which lacks OH groups, crystallizes in cyclic dimers that are stabilized by N-HÁ Á ÁN hydrogen bonds. The tautomerism in solution and in the solid state was determined by 13 C and 15 N CPMAS NMR spectroscopy. For compounds 4, 5 and 8, the solid state results agree with those observed by crystallography; the most abundant tautomer in solution coincides with the tautomer present in the solid state (4 and 8) or with the most abundant tautomer in the crystal . , 33, 125-135 | 125 PAPER www.rsc.org/njc | New Journal of Chemistry a The coupling constants were, on average: 3 J H3-H4 = 8.0 Hz, 4 J H4-H6 = 2.0 Hz (not always observed) and 3 J H7-H8 trans = 16.5 Hz.
Helvetica Chimica Acta, 2004
Compounds [{Au(pz)(PPh3)}2] (pz=3,5-disubstituted pyrazolato; R=BuOC6H4 (bp), 1; R=C8H17OC6H4 (op... more Compounds [{Au(pz)(PPh3)}2] (pz=3,5-disubstituted pyrazolato; R=BuOC6H4 (bp), 1; R=C8H17OC6H4 (op), 2; R=C6H13OC6H4 (hp), 3) were easily obtained by reaction of [Au(NO3)(PPh3)] and the corresponding pyrazolato ligand. They exhibit similar NMR patterns, their ESI-MS or FAB-MS data being in agreement with a monomeric molecular formulation [Au(pz)(PPh3)]. By contrast, 1 crystallizes as the dimer [{Au(pz)(PPh3)}2] and exhibits aurophilic Au ⋅⋅⋅Au contacts, while crystallization of 2 in CH2Cl2/hexane gives rise to compound 4, [Au(pz)(PPh3)]⋅(Hpz). The X-ray structure of 4 was solved, showing a H-bond interaction between the monomer of 2 and Hpz. Reactions between [{Au(pz)(PPh3)}2] and their corresponding 1H-pyrazole (Hpz) were also explored. Compounds 1–3 exhibit luminescence in the solid state. Their emission spectra are reported and analyzed.
Inorganic Chemistry, 2005
New hydridoirida-beta-diketones [IrH[(PPh2(o-C6H4CO))2H](CO)]ClO4 2 and [IrH[(PPh2(o-C6H4CO))2H](... more New hydridoirida-beta-diketones [IrH[(PPh2(o-C6H4CO))2H](CO)]ClO4 2 and [IrH[(PPh2(o-C6H4CO))2H](olefin)]BF4 (olefin = C2H4, 5; 1-hexene, 10) have been prepared. These complexes may afford new diacylhydridoiridium(III) derivatives. In chloroform solution, complex 2 is in equilibrium with the deprotonated diacylhydride trans-[IrH(PPh2(o-C6H4CO))2(CO)] complex 3. In DMSO, deprotonation of 2 occurs to yield the kinetically favored product 3, which isomerizes to the thermodynamically favored complex cis-[IrH(PPh2(o-C6H4CO))2(CO)] 4. Reprotonation of 4 with HBF4 in chlorinated solvents gives the cation in 2. In coordinating solvents such as dimethyl sulfoxide or acetonitrile, complex 5 undergoes displacement of ethylene to afford [IrH{(PPh2(o-C6H4CO))2H](L)]BF4 (L = DMSO, 7; CH3CN, 9). Complexes 5 and 7 undergo deprotonation by NEt3 to give the corresponding diacylhydrides. The ethylene complex gives only trans-[IrH(PPh2(o-C6H4CO))2(C2H4)] 6, while the dimethyl sulfoxide derivative affords a mixture of trans- and cis-[IrH(PPh2(o-C6H4CO))2(DMSO)] 8. Complex 10 shows inhibited alkene rotation around the Ir-olefin axis. All of the complexes were fully characterized spectroscopically. Single-crystal X-ray diffraction analysis was performed on complexes 3, 4, and 9. The 13C NMR and X-ray data point to a carbenoid character in the carbon atoms bonded to iridium in the irida--diketone fragment, so that it can be considered as an acyl(hydroxycarbene) moiety.
Organometallics, 2007
RhCl(COD)] 2 (COD ) 1,5-cyclooctadiene) reacts with o-(diphenylphosphino)benzaldehyde (PPh 2 -(o-... more RhCl(COD)] 2 (COD ) 1,5-cyclooctadiene) reacts with o-(diphenylphosphino)benzaldehyde (PPh 2 -(o-C 6 H 4 CHO)) (Rh/P ) 1:1) in the presence of pyridine to give an acyl hydrido species, [RhHCl(PPh 2 -(o-C 6 H 4 CO))(py) 2 ] (1). In chlorinated solvents exchange of hydride by chloride gives [RhCl 2 (PPh 2 (o-C 6 H 4 CO))(py) 2 ] (2). The reactions of 1 with PPh 3 and of 2 with biacetyl dihydrazone (bdh) gives the pyridine substitution products [RhHCl(PPh 2 (o-C 6 H 4 CO))(PPh 3 )(py)] (4) and [RhCl 2 (PPh 2 (o-C 6 H 4 CO))-(bdh)] (3), respectively. By using a 1:2 ratio of Rh to PPh 2 (o-C 6 H 4 CHO) [RhHCl(PPh 2 (o-C 6 H 4 CO))(κ 1 -PPh 2 (o-C 6 H 4 CHO))(py)] (5) with trans phosphorus atoms is formed. The aldehyde group may undergo two different reactions. In benzene 5 affords the acyl hydroxyalkyl species [RhCl(PPh 2 (o-C 6 H 4 CO))-(PPh 2 (o-C 6 H 4 CHOH))(py)] (6) with cis phosphorus atoms, via a pyridine dissociation path. 6 undergoes dehydrogenation, with H 2 evolution, to afford the diacyl derivative [RhCl(PPh 2 (o-C 6 H 4 CO)) 2 (py)] (8), which shows fluxional behavior in solution, with the values ∆H q ) 8.8 ( 0.4 kcal mol -1 and ∆S q ) -16.7 ( 1 eu. Opening of the acylphosphine chelate appears to be responsible for the fluxionality. In methanol 5 undergoes displacement of chloride by the aldehyde to afford the cationic acyl hydrido aldehyde [RhH(PPh 2 (o-C 6 H 4 CO))(κ 2 -PPh 2 (o-C 6 H 4 CHO))(py)] + (10), which can be isolated if precipitated immediately with an appropriate counterion. Longer reaction periods of 5 in methanol solution lead to a mixture of the diacyl 8 and the cationic acyl hydrido alcohol [RhH(PPh 2 (o-C 6 H 4 CO))(κ 2 -PPh 2 (o-C 6 H 4 -CH 2 OH))(py)] + (11). The spectroscopic characterization of some intermediates in this reaction evidence a bimolecular ionic mechanism as being responsible for the hydrogenation of the aldehyde with the hydroxyalkyl 6 being the source of both proton and hydride. Complex 11 can also be obtained by the reaction of 5 with NaBH 4 in methanol solution.
Supramolecular Chemistry, 2006
... DOI: 10.1080/10610270600594865 Rosa M. Claramunt a * , Pilar Cornago a , M. Dolores Santa Mar... more ... DOI: 10.1080/10610270600594865 Rosa M. Claramunt a * , Pilar Cornago a , M. Dolores Santa María a , Verónica Torres a , Elena Pinilla b , M. Rosario Torres b & José Elguero c pages 349-356. Available online: 04 Mar 2011. ...
Helvetica Chimica Acta, 2004
Ten new silver and gold trimeric complexes of the type [M3(μ-pz′)3] (M=Au, Ag), where pz′ indicat... more Ten new silver and gold trimeric complexes of the type [M3(μ-pz′)3] (M=Au, Ag), where pz′ indicate pyrazolato ligands derived from mesogenic 3,5-disubstituted 1H-pyrazoles or non-mesogenic 3-substituted 1H-pyrazoles HpzR (R=C6H4OCnH2n+1), were synthesized and characterized. The gold and silver complexes 7, 8, 10, and 11 containing symmetric pyrazolato ligands as bridging groups (; R=C6H4OCnH2n+1, n=4 () and 8 ()) exhibited a trigonal symmetric structure. The same results were obtained for the related silver derivatives 16–18 with 3-substituted pyrazolato ligands (pzR; R=C6H4OCnH2n+1, n=4 (pzbp), 12 (pzddp), and 18 (pzodp)). By contrast the 3-substituted pyrazolato-gold compounds 13–15 adopted an asymmetric molecular structure related to the position of the substituents on the trinuclear core. The thermal behavior of these complexes was investigated by differential scanning calorimetry and polarized-light microscopy. The mesomorphism of the parent 3,5-disubstituted pyrazoles is avoided in their corresponding trinuclear complexes 7, 8, 10, and 11. However, the metal derivatives 14 and 17 containing the asymmetric 3-[4-(dodecyloxy)phenyl]pyrazolato ligand were found to have liquid-crystal properties. These compounds exhibited monotropic behavior with columnar mesophases that could be related to the disc-like shape of the molecular core and the appropriate length of the alkyloxy chain. For comparative purposes, the X-ray structure of the related gold complex [Au3(μ-)3] (9) having phenoxyphenyl substituents at the 3- and 5-positions of the pyrazolato ligand is also described. The molecular structure is formed by a non-planar (AuNN)3 core, containing three Au-atoms bridged by three pyrazolato ligands. The molecular packing is described as a columnar organization, the shortest Au ⋅⋅⋅Au distance being 4.639(1) Å between consecutive trimers.
Helvetica Chimica Acta, 2002
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European Journal of Inorganic Chemistry, 2006
The hydridoirida-β-diketone [IrH{[PPh2(o-C6H4CO)]2H}Cl] (1) reacts with silver salts of potential... more The hydridoirida-β-diketone [IrH{[PPh2(o-C6H4CO)]2H}Cl] (1) reacts with silver salts of potentially coordinating anions such as tosylate (–OTs) or triflate (–OTf) to afford the mononuclear neutral derivatives [IrH{[PPh2(o-C6H4CO)]2H}(X)] [X = OTs (2), OTf (3)]. In acetone solution the triflate anion in 3 is displaced by the solvent to afford the cationic complex [IrH{[PPh2(o-C6H4CO)]2H}(acetone)]OTf (4), which is stable only in acetone solution. The reaction of 1 with halide scavengers containing less coordinating anions such as PF6– or BF4– results in the formation of cationic compounds [{IrH[{PPh2(o-C6H4CO)}2H]}2(μ-Cl)]A [A = BF4 (5), PF6 (6)] containing a dinuclear species with a single chlorine atom bridging two hydridoirida-β-diketone fragments. Both fragments are magnetically non-equivalent and the acylphosphane groups in each hydridoirida-β-diketone fragment are chemically equivalent. This species undergoes a fluxional process in solution, with ΔH‡ = 7.8 ± 0.4 kcal mol–1 and ΔS‡ = –10.9 ± 0.5 eu. A combination of rotation around the Ir–Cl bonds and variation of the Ir–Cl–Ir angle is suggested to be responsible for the fluxionality. Complex 5 reacts further with AgBF4 to undergo chloride abstraction along with hydrogen loss and deprotonation to give the cationic dinuclear complex [Ir2H{PPh2(o-C6H4CO)}{μ-PPh2(o-C6H4CO)}3]BF4 (7), which contains an acylphosphane chelate along with three acylphosphane bridging ligands and a single hydrido ligand. Bubbling of HCl through an MeOH solution of 7 gives 1, thus making the loss of hydride, enolic protons and chloride from complex 1 a reversible process. All the complexes were fully characterized spectroscopically. Single-crystal X-ray diffraction analysis was performed on complexes 5 and 7. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Dalton Transactions, 2008
The hydridoirida-beta-diketone [IrHCl{(PPh2(o-C6H4CO))2H}] (1a) reacts with bases such as KOH or ... more The hydridoirida-beta-diketone [IrHCl{(PPh2(o-C6H4CO))2H}] (1a) reacts with bases such as KOH or NaHCO3 in methanol to undergo dehydrodechlorination and acyl-bridge formation affording [Ir2H2(PPh2(o-C6H4CO))2(mu-PPh2(o-C6H4CO))2] (2) with two acylphosphine chelate-bridging ligands, in a head-to-tail disposition, and terminal hydrides. The acyl bridges can be broken by pyridine, PPh3, CO or dimethylsulfoxide affording selectively mononuclear diacylhydrido neutral derivatives [IrH(PPh2(o-C6H4CO))2L] (3-6). la reacts with KOH or NaHCO3 in refluxing methanol to afford a novel dihydridoirida-beta-diketone [IrH2{(PPh2(o-C6H4CO))2H}](7), via dehydrodechlorination to afford 2, which then undergoes hydrogenation and protonation. The reaction of la with NEt3 affords 2 and [NHEt3]Cl. Further reaction affords [Ir2(mu-H){mu-PPh2(o-C6H4CO)}2(PPh2(o-C6H4CO))2] (8), with two acylphosphine chelate-bridging ligands and a bridging hydride. Neutral or cationic hydridoirida-beta-diketone complexes react with [Rh(cod)(OMe)]2 (cod = 1,5-cyclooctadiene) to afford hydridoirida-P-diketonaterhodium(I) complexes [IrHCl(mu-PPh2(o-C6H4CO))2Rh(cod)] (9) or [IrHL(mu-PPh2(o-C6H4CO))2Rh(cod)]ClO4 (L = py, 10; CO, 11), respectively that isomerise to the thermodynamically stable isomers of [IrCl(PPh2(o-C6H4CO))(mu-H))(mu-PPh,2(o-C6H4CO))Rh(cod)] (12) or [Ir(py)(PPh2(o-C6H4CO))(mu-H))(mu-PPh2(o-C6H4CO))Rh(cod)]ClO4(13). The reaction of 7 with [Rh(cod)(OMe)]2 affords [Ir(PPh2(o-C6H4CO))2(mu-H)2Rh(cod)](14). All the complexes were fully characterised spectroscopically. Single-crystal X-ray diffraction analysis was performed on 2, 4, 7, [8]ClO4 and 9.
Crystal Growth & Design, 2007
Solid-state reactions of 3, 5-dimethyl-1 H-pyrazole (dmpz) and salicylic acid (sa) in different s... more Solid-state reactions of 3, 5-dimethyl-1 H-pyrazole (dmpz) and salicylic acid (sa) in different stoichiometries afford two different trimers whose structures have been determined by X-ray diffraction and analyzed by 13C and 15N solid-state nuclear magnetic resonance ...
Journal of Organometallic Chemistry, 1996
Solution studies by 1H and 13C NMR and IR spectroscopy of rhodium(I) complexes TpPhRh(NBD) 1, TpP... more Solution studies by 1H and 13C NMR and IR spectroscopy of rhodium(I) complexes TpPhRh(NBD) 1, TpPhRh(COD) 2 and TpPhRd(CO)23 (NBD = 2,5-norbornadiene, COD = 1,5-cyclooctadiene) show that these compounds exist as mixtures of two isomeric square-planar complexes containing the TpPh ligand in a bidentate k2-bonded form, with the third uncoordinated pyrazolyl ring occupying an equatorial position, form A, or an axial position, form B. In the solid state the complexes are tetracoordinated, as proved by X-ray crystallography: 1 (monoclinic, space group P21/c) and 2 (orthorhombic, space group P212121), whose structures correspond to forms B and A respectively. Changes in the A/B ratio in the solid complex TpPhRh(CO)23 were observed after several months.
Journal of Materials Chemistry, 1999
The organometallic compounds [4-O 2 NC 6 H 3 (2-CH 3 )NLNC 6 H 3 (5∞-CH 3 )-2∞-(g5-C 5 H 4 )Fe(g5... more The organometallic compounds [4-O 2 NC 6 H 3 (2-CH 3 )NLNC 6 H 3 (5∞-CH 3 )-2∞-(g5-C 5 H 4 )Fe(g5-C 5 H 5 )] 1 and ... [Mo(Cl)(TpAn)(NO){NHC 6 H 3 (3-CH 3 )[NLNC 6 H 3 (5-CH 3 )-2-(g5-C 5 H 4 )Fe(g5-C 5 H 5 )]-4}] 2 {TpAn=hydrotris[3-
Inorganic Chemistry Communications, 2002
A new family of linear Pd(II) complexes based on pyrazoles containing long-chain substituents at ... more A new family of linear Pd(II) complexes based on pyrazoles containing long-chain substituents at the third position has been prepared and their mesomorphic properties studied. The crystalline structure of one of these compounds is described as a representative example of a very elongated and straight molecule.
European Journal of Inorganic Chemistry, 2004
New AuI/AgI complexes containing one or two substituted pyrazole ligands [Au(Hpzbp2)(PPh3)](p-CH3... more New AuI/AgI complexes containing one or two substituted pyrazole ligands [Au(Hpzbp2)(PPh3)](p-CH3C6H4SO3) [Hpzbp2 = 3,5-bis(4-n-butoxyphenyl)pyrazole] (1) and [M(HpzR2)2]nX [HpzR2 = Hpzbp2, M = Au, n = 1, X = p-CH3C6H4SO3 (2), NO3− (3); n = 2, X = 1,5-naphthalenedisulfonate (1,5nds) (4); HpzR2 = Hpzbp2, M = Ag, n = 1, X = BF4− (5), CF3SO3− (6); HpzR2 = HpzNO2 (3,5-dimethyl-4-nitropyrazole), M = Ag, n = 1, X = BF4− (7), CF3SO3− (8)], have been prepared and characterized. Compounds 1, 2, 5 and 8 have been proved to be useful for supramolecular assembly from their single X-ray diffraction analysis. In all cases strong hydrogen bonds maintain the cationic units bonded to their corresponding counterions. The crystal packing arrangement of 1, 2 and 5 is, however, determined by weak C−H···O/F hydrogen-bonding interactions involving the remaining O/F atoms of the counterion. By contrast, for 8 a two-dimensional layer-type polymeric network is formed by π···π (NO2···NO2) and coordinative Ag···O interactions in which the NO2 substituent on the pyrazole is implicated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
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Helvetica Chimica Acta, 2001
Copper(II) complexes containing β-diketonato ligands of the general formula [Cu{(4-RO)C 6 H 4 COC... more Copper(II) complexes containing β-diketonato ligands of the general formula [Cu{(4-RO)C 6 H 4 COCHCOC 6 H 4 (4-OR)} 2 ] 3 (R=Bu) or 4 (R=Ph) were prepared and their structures solved by X-ray diffraction. The crystal structure of the parent ligand (4-BuO)C 6 H 4 COCH 2 ...
Journal of The Less Common Metals, 1980
The preparation, properties and catalytic activity of new cationic rhodium(I) complexes of the ge... more The preparation, properties and catalytic activity of new cationic rhodium(I) complexes of the general formulae [ Rh(NBD)Ls] C104 and [Rh(NBD)L(PRs)]
European Journal of Inorganic Chemistry, 2003
The 3,5-bis(4-butoxyphenyl)pyrazolyl group (Pzbp2) has been used as a building block for mono- an... more The 3,5-bis(4-butoxyphenyl)pyrazolyl group (Pzbp2) has been used as a building block for mono- and polymetallic derivatives of 2,4,6-tris[3,5-bis(4-butoxyphenyl)pyrazol-1-yl]-1,3,5-triazine (TPzbp2Tz, 1), 2-[3,5-bis(4-butoxyphenyl)pyrazol-1-yl]pyridine (Pzbp2Py, 2), and 3,5-bis(4-butoxyphenyl)pyrazole (HPzbp2, 3) ligands. The synthesis and characterisation of the new hexadentate ligand 1 are described, together with the chemistry of its metal complexes containing [Pd(η3-C3H5)]+ and [Au(PPh3)]+ fragments. The related complexes containing Pzbp2Py (2) were also studied and their structural characteristics were compared to those of the TPzbp2Tz species. The role of the counter-ion on the supramolecular assembly of complexes containing the HPzbp2 ligand 3 was made clear by the X-ray structures of [Pd(η3-C3H5)(HPzbp2)2](BF4) and [Au(HPzbp2)(PPh3)](NO3). Hydrogen bonds and/or bonding interactions are responsible for pseudohelical one-dimensional polymers or supramolecular columnar arrays, respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)