21 results on '"Rodríguez-Diéguez A"'
Search Results
2. Towards correlating dimensionality and topology in luminescent MOFs based on terephthalato and bispyridyl-like ligands
- Author
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Sonia Pérez-Yáñez, Javier Cepeda, Antonio Rodríguez-Diéguez, José Ángel García, and Sara Rojas
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Inorganic Chemistry ,Crystallography ,Photoluminescence ,Materials science ,Metal ions in aqueous solution ,Luminescence ,Ternary operation ,Exfoliation joint ,Topology (chemistry) ,Spectral line ,Curse of dimensionality - Abstract
Herein, we report on the synthesis, structural analysis, physicochemical characterization and photoluminescence performance of two ternary compounds based on dicarboxylate and bispyridyl-like ligands and metal ions of group 12, namely [Zn2(μ4-bdc)(μ-pbptz)(DMF)2(NO3)2]n (1-Zn) and {[Cd(μ3-bdc)(μ-pbptz)]·DMF}n (2-Cd) (where bdc = benzene-1,4-dicarboxylate, pbptz = 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine, and DMF = N,N-dimethylformamide). 1-Zn, consisting of a 2D-layered framework, can be considered as the lower-dimensional analogue of the previously reported {[Zn2(μ4-bdc)2(μ-pbptz)]·2DMF·3H2O}n 3D MOF (1′-Zn), which is shown to recrystallize into 1-Zn undergoing a kind of exfoliation. 2-Cd presents a 3D doubly interpenetrated framework whose porosity is reduced to approximately half of the available solvent-accessible voids contained in the non-interpenetrated homologue reported so far, {[Cd(μ3-bdc)(μ-pbptz)]·3DMF}n (2′-Cd). Structural factors leading to each of the alternative frameworks are detailed by analysing the building units with a perusal of the Cambridge Structural Database and providing a comparative description of the structures. The photoluminescence properties of herein reported compounds (1-Zn and 2-Cd) are also measured and the processes governing the spectra are described using time-dependent density-functional theory (TD-DFT), which allows establishing some structural correspondences by comparing these results with those of the 1′-Zn and 2′-Cd analogues.
- Published
- 2021
3. Effect of the change of the ancillary carboxylate bridging ligand on the SMM and luminescence properties of a series of carboxylate-diphenoxido triply bridged dinuclear ZnLn and tetranuclear Zn
- Author
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E, Echenique-Errandonea, A, Zabala-Lekuona, J, Cepeda, A, Rodríguez-Diéguez, J M, Seco, I, Oyarzabal, and E, Colacio
- Abstract
Eleven new dinuclear and tetranuclear compounds of general formulae [Zn(μ-L)(μ-X)Ln(NO3)2]·nS, [Zn2Dy2(μ3-L')2(μ-sal)2(NO3)(CH3OH)](NO3)·5CH3OH and [Zn2Er2(μ3-L')2(μ-sal)2(CH3OH)2](NO3)2·4CH3OH (X = benzoate, anthracenate, diclofenac, salicylate, 2,6-dihydroxybenzoate; Ln = Dy, Er; S = water, acetonitrile, methanol) were prepared from the N,N'-dimethyl-N,N'-bis(2-hydroxy-3-formyl-5-bromobenzyl)ethylenediamine compartmental ligand (H2L). Complexes 1-6 and 9-11 consist of diphenoxido-carboxylate triply bridged compounds, which differ mainly in the carboxylate bridging ligand. It should be noted that the acidic character of the salicylic acid promotes, in the presence of methanol, the methoxylation of the H2L ligand thereby yielding a hemiacetal H3L', which is able to connect the Ln(iii) ions of two ZnLn dinuclear units forming the Zn2Ln2 tetranuclear complexes 7 and 8. All compounds display SMM behaviour in the presence of an external field with effective energy barriers (Ueff) as high as 61 K. Magneto-structural data for these complexes reveal that their SMM behaviour is not only significantly affected by the type of Ln(iii) ion but also by the carboxylate bridging ligand connecting the Zn(ii) and Ln(iii) ions. Photoluminescence properties have also been accomplished, showing that the ligands are able to sensitize lanthanide centred emissions in the visible and near-infrared regions with variable capacity. Moreover, the analysis of the luminescence decay curves reveals emission lifetimes in the range of few microsecond or hundreds of nanoseconds for Dy(iii)-based or Er(iii)-based luminophores, respectively.
- Published
- 2018
4. Design and synthesis of a family of 1D-lanthanide-coordination polymers showing luminescence and slow relaxation of the magnetization
- Author
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Enrique Colacio, Javier Cepeda, Antonio Rodríguez-Diéguez, Ana Belén Ruiz-Muelle, Amalia García-García, Ignacio Fernández, Itziar Oyarzabal, Antonio A. García-Valdivia, and José M. Seco
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Lanthanide ,chemistry.chemical_classification ,Materials science ,010405 organic chemistry ,Relaxation (NMR) ,Supramolecular chemistry ,Polymer ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Crystallography ,Magnetization ,chemistry ,Molecule ,Isostructural ,Luminescence - Abstract
We have designed and synthesized eight isostructural 1D coordination polymers (CPs) with the general formula {[Ln(aapc)3(DMF)]}n [where Ln(iii) = Y (2), La (3), Nd (4), Eu (5), Gd (6), Tb (7), Dy (8), Er (9); and aapc = 3-((anthraquinone-1-yl)amino)propanoate]. These CPs consist of Ln-carboxylate infinite rods in which the bulky anthraquinone scaffolds arise from it in such a way that the resulting supramolecular packing exhibits isolated 1D chains. Solution structures have been corroborated through NMR methods including PGSE and EXSY NMR studies and, due to the presence of lanthanide ions, magnetic and luminescence properties have been studied. Alternating current magnetic measurements of compound 8 show slow relaxation of the magnetization, a characteristic of single molecule magnets (SMMs). The evaluation of solid-state photophysical properties reveals that the aapc scaffold sensitizes lanthanide(iii) based emission of compounds 4-9 both in the visible and near-infrared (NIR) regions at 10 K.
- Published
- 2018
5. Chiral coordination polymers based on d
- Author
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Oier, Pajuelo-Corral, Antonio, Rodríguez-Diéguez, Jose A, García, Eider, San Sebastián, Jose M, Seco, and Javier, Cepeda
- Abstract
Herein, we report the detailed structural characterization and photoluminescence (PL) properties of two new isostructural coordination polymers (CPs) based on 2-aminonicotinate (2ani) ligand and zinc(ii) or cadmium(ii) metal ions, namely, [M(μ-2ani)2]n [MII = Zn(1) and Cd(2)]. These compounds are characterized as chiral 2D-layered structures, resulting from the bridging of the 2ani ligands in the MN2O4 coordination shell. Also, strong supramolecular interactions are found to sustain the overall crystal structure, which endows these materials with high stability. The single crystals of 1 exhibit waveguiding behaviour along some preferred orientations. The examination of the polycrystalline samples of both compounds under UV light also shows that the samples exhibit remarkably strong PL emissions, which consist of blue fluorescence and green phosphorescence involving long-lasting phosphorescence (LLP) at low temperature. Fitting of the decay curves confirms the occurrence of short (in the order of nanoseconds) and very large lifetimes (τ ≈ 320 and 560 ms for 1 and 2, respectively) of the wavelengths responsible for their blue and green emissions, respectively, which have been studied using DFT calculations.
- Published
- 2018
6. Alkene-alkyl interconversion: an experimental and computational study of the olefin insertion and β-hydride elimination processes
- Author
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E. San Sebastian, Antonio Rodríguez-Diéguez, Susan Azpeitia, Miguel A. Huertos, María A. Garralda, and U Prieto
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chemistry.chemical_classification ,Olefin fiber ,010405 organic chemistry ,Alkene ,Hydride ,Norbornadiene ,Cationic polymerization ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Intramolecular force ,Isomerization ,Alkyl - Abstract
The preparation and characterization of various alkyl, allyl or alkene Rh(iii) and Ir(iii) complexes as well as studies on the intramolecular reactions leading to transformation of one into another are reported. The silyl-hydrido-Rh(iii) complex {Rh(H)[SiMe(o-C6H4SMe)2](PPh3)}[BArF4], with a vacant coordination site, reacts with 1,5-cyclooctadiene (cod) leading to olefin insertion into the Rh-H bond and rearrangement to yield the 16e cyclooctenyl-Rh(iii) complex {Rh(η3-cyclooctenyl)[SiMe(o-C6H4SMe)2]}[BArF4] (1). This compound can be also synthesized by reaction of the 18e chloride precursor {Rh(η3-cyclooctenyl)[SiMe(o-C6H4SMe)2]Cl} with NaBArF4. The reaction of the thioether-silane SiMeH(o-C6H4SMe)2 with [Rh(nbd)Cl]2 (nbd = norbornadiene) leads to {Rh(σ-ntyl)[SiMe(o-C6H4SMe)2]Cl} (ntyl = nortricyclyl) (2). The abstraction of chloride from this neutral 16e ntyl-Rh(iii) complex with NaBArF4 results in the unusual isomerization of σ-nortricyclyl into σ,π-norbornenyl forming the 16e and cationic {Rh(σ,π-nbyl)[SiMe(o-C6H4SMe)2][BArF4] (nbyl = norbornenyl)} compound 3. Coordinatively saturated {Ir(η3-cyclooctenyl)[SiMe(o-C6H4SMe)2]Cl} (4) has been synthesized by the reaction of [Ir(cod)Cl]2 with SiMeH(o-C6H4SMe)2. The reaction of 4 with NaBArF4 led to the formation of the unsaturated and cationic Ir(iii) compound {Ir(η3-cyclooctenyl)[SiMe(o-C6H4SMe)2]}[BArF4] (5). Compound 5 shows low stability in solution and undergoes successive β-hydride elimination and olefin insertion steps, which were elucidated by DFT calculations, to form 18e {Ir(H)[SiMe(o-C6H4SMe)2](η4-cod)}[BArF4] (6).
- Published
- 2018
7. Simple ZnEt
- Author
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Antonio, Martínez, Sonia, Moreno-Blázquez, Antonio, Rodríguez-Diéguez, Alberto, Ramos, Rafael, Fernández-Galán, Antonio, Antiñolo, and Fernando, Carrillo-Hermosilla
- Abstract
Expanding the possibilities of the use of simple and available ZnEt
- Published
- 2017
8. Insertion reactions of small unsaturated molecules in the N-B bonds of boron guanidinates
- Author
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Alberto Ramos, Elena Villaseñor, Antonio Antiñolo, Fernando Carrillo-Hermosilla, Rafael Fernández-Galán, Antonio Rodríguez-Diéguez, Daniel García-Vivó, and María Pilar Montero-Rama
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010405 organic chemistry ,Chemistry ,Stereochemistry ,Dimer ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Reversible reaction ,0104 chemical sciences ,Inorganic Chemistry ,Benzaldehyde ,chemistry.chemical_compound ,Crystallography ,Deprotonation ,Molecule ,Nonane ,Guanidine ,Boron - Abstract
We report here 1,1- and 1,2-insertion reactions of small unsaturated molecules in the N–B bonds of two boron guanidinates, (Me2N)C(NiPr)2BCy2 (1) and {iPr(H)N}C(NiPr){N(p-tBu-C6H4)}BCy2 (2), and two bisboron guanidinates(2–), {iPr(BCy2)N}C(NiPr){N(p-tBu-C6H4)}BCy2 (3) and {iPr(C8H14B)N}C(NiPr){N(p-Me-C6H4)}BC8H14 (4), the latter being prepared for the first time by double deprotonation of the corresponding guanidine with the 9-borabicyclo[3.3.1]nonane dimer, (H-BC8H14)2. Compounds 1–4 easily insert aromatic isonitriles, XylNC (Xyl = 2,6-Me2-C6H3) and (p-MeO-C6H4)NC, to give the expected diazaboroles 5–12, some of them being structurally characterised by X-ray diffraction. Interestingly, the BC8H14 derivatives 11 and 12 are in a fast temperature-dependent equilibrium with the de-insertion products, whose thermodynamic parameters are reported here. A correlation between these equilibria and the puckered heterocyclic structure found in the solid state for 11, and confirmed by DFT calculations, is also established. Reactions of the aforementioned guanidinates with CO are more sluggish or even precluded, and only one product, {iPr(H)N}C{N(p-tBu-C6H4)}(NiPr)(CO)BCy2 (13), could be isolated in moderate yields. The 1,2-insertions of benzaldehyde in compounds 1, 2 and 4 are reversible reactions in all cases, and only one of the insertion products, {iPr(H)N}C{N(p-tBu-C6H4)}(NiPr)(PhHCO)BCy2 (16a), was isolated and diffractrometrically characterised. Likewise, CO2 reversibly inserts into a N–B bond of 2 to give {iPr(H)N}C{N(p-tBu-C6H4)}(NiPr)(CO2)BCy2 (19) with a conversion of ca. 9%. In all these equilibria, de-insertion is always favoured upon increasing the temperature.
- Published
- 2017
9. The effect of the disposition of coordinated oxygen atoms on the magnitude of the energy barrier for magnetization reversal in a family of linear trinuclear Zn-Dy-Zn complexes with a square-antiprism DyO
- Author
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Itziar, Oyarzabal, Antonio, Rodríguez-Diéguez, Montserrat, Barquín, José M, Seco, and Enrique, Colacio
- Abstract
A series of trimetallic Zn-Dy-Zn complexes of the general formula [ZnX(μ-L)Dy(μ-L)XZn]Y·nS, where H
- Published
- 2017
10. Self-assembly synthesis, structure, topology, and magnetic properties of a mononuclear Fe(iii)-violurate derivative: a combined experimental and theoretical study
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Alexander M. Kirillov, Rupak Banik, Antonio Frontera, Ján Titiš, Antonio Rodríguez-Diéguez, Subrata Das, Adam D. Martin, Subhadip Roy, Antonio Bauzá, Juan M. Salas, Ľubor Dlháň, and Roman Boča
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010405 organic chemistry ,Stereochemistry ,Crystal structure ,Coercivity ,010402 general chemistry ,Magnetic hysteresis ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,Pyridine ,Antiferromagnetism ,Self-assembly ,Derivative (chemistry) ,Topology (chemistry) - Abstract
A new iron(III) complex [Fe(H2Vi)3]·py·4H2O (1) {H3Vi = violuric acid, py = pyridine} was self-assembled and characterized. In the crystal structure, adjacent [Fe(H2Vi)3] blocks are H-bonded into a complex 3D network, which was topologically classified as a pcu [alpha-Po primitive cubic] network. Importance of π-stacking interactions was also highlighted and analyzed computationally. Magnetic studies confirmed antiferromagnetic exchange coupling, while ZFCM/FCM experiments indicated an ordering temperature Tc = 50 K. Finally, magnetic hysteresis at 5 K possesses the coercive field of Bc = 69 mT.
- Published
- 2016
11. Dialkylboron guanidinates: syntheses, structures and carbodiimide de-insertion reactions
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Elena Villaseñor, Alberto Ramos, Antonio Antiñolo, María Pilar Montero-Rama, Antonio Rodríguez-Diéguez, Rene S. Rojas, Rafael Fernández-Galán, and Fernando Carrillo-Hermosilla
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010405 organic chemistry ,Ligand ,Chemistry ,Stereochemistry ,chemistry.chemical_element ,010402 general chemistry ,Metathesis ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,Dilithium ,chemistry.chemical_compound ,Chelation ,Lithium ,Carbodiimide - Abstract
The synthesis of novel dialkylboron guanidinates is reported: the symmetrical compounds, (Me2N)C(NR)2BR′2 [R = iPr, R′ = Nrb (1); R = Cy, R′ = Nrb (2); R = iPr, R′ = Cy (3); R = R′ = Cy (4); R = 2,6-iPr2-C6H3; R′ = Cy (5); Nrb = exo-2-norbornyl] and the asymmetrically coordinated {iPr(H)N}C(NiPr)(NAr)BCy2 [Ar = Ph (6), 4-Me-C6H4 (7), 4-tBu-C6H4 (8)] were prepared by the salt metathesis method from the appropriate lithium guanidinates and chloroboranes. Moreover, the bis(dicyclohexylboron)guanidinate(−2) {iPr(Cy2B)N}C(NiPr){N(4-tBu-C6H4)}BCy2 (9) was also prepared from the corresponding dilithium guanidinate Li2[{N(4-tBu-C6H4)}C(NiPr)2] and ClBCy2. The structures of compounds 1, 3, 6 and 9 were confirmed by X-ray diffraction and all displayed a chelate coordination of the guanidinate ligand to the BR′2 fragment, the latter displaying an additional BCy2 attached to the exocyclic N atom. Solutions of compounds 1–4 reached an equilibrium with the aminoboranes Me2NBR′2 [R′ = Nrb (10), Cy (11)] and the corresponding carbodiimides, which was slow at 25 °C. The thermodynamic parameters for these equilibria are also reported. The activation parameters for the equilibrium for compound 1 have been calculated after a kinetic study. Compounds 5–8, with one or two N-aryl fragments bound to a B centre, are more robust and need higher temperatures (80 °C) and prolonged times to give similar carbodiimide de-insertion reactions.
- Published
- 2016
12. A family of acetato-diphenoxo triply bridged dimetallic Zn(II)Ln(III) complexes: SMM behavior and luminescent properties
- Author
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Itziar Oyarzabal, Enrique Colacio, José M. Seco, Beñat Artetxe, Antonio Rodríguez-Diéguez, and José Ángel García
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010405 organic chemistry ,Ligand ,Relaxation (NMR) ,Inorganic chemistry ,Relaxation process ,Ethylenediamine ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Ion ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Crystallography ,chemistry ,visual_art ,visual_art.visual_art_medium ,Luminescence - Abstract
Eleven dimetallic Zn(II)-Ln(III) complexes of the general formula [Zn(µ-L)(µ-OAc)Ln(NO3)2]·CH3CN (Ln(III) = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7), Ho (8), Er (9), Tm (10), Yb (11)) have been prepared in a one-pot reaction from the compartmental ligand N,N'-dimethyl-N,N'-bis(2-hydroxy-3-formyl-5-bromo-benzyl)ethylenediamine (H2L). In all these complexes, the Zn(II) ions occupy the internal N2O2 site whereas the Ln(III) ions show preference for the O4 external site. Both metallic ions are bridged by an acetate bridge, giving rise to triple mixed diphenoxido/acetate bridged Zn(II)Ln(III) compounds. The Nd, Dy, Er and Yb complexes exhibit field induced single-ion magnet (SIM) behaviour, with Ueff values ranging from 14.12 to 41.55 K. The Er complex shows two relaxation processes, but only the second relaxation process with an energy barrier of 21.0 K has been characterized. The chromophoric L(2-) ligand is able to act as an "antenna" group, sensitizing the near-infrared (NIR) Nd(III) and Yb(III)-based luminescence in complexes 2 and 11 and therefore, both compounds can be considered as magneto-luminescent materials. In addition, the Sm(III), Eu(III) and Tb(III) derivatives exhibit characteristic emissions in the visible region.
- Published
- 2016
13. Stereoselective formation and catalytic activity of hydrido(acylphosphane)(chlorido)(pyrazole)rhodium(III) complexes. Experimental and DFT studies
- Author
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Antonio Rodríguez-Diéguez, Eider San Sebastian, Lourdes Ibarlucea, Virginia San Nacianceno, José M. Seco, Susan Azpeitia, Claudio Mendicute-Fierro, and María A. Garralda
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Hydrogen bond ,Ligand ,Stereochemistry ,chemistry.chemical_element ,Pyrazole ,Medicinal chemistry ,Tautomer ,Catalysis ,Rhodium ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Intramolecular force ,Linkage isomerism - Abstract
The reaction of [{RhCl(COD)}2] (COD = 1,5-cyclooctadiene) with L = pyrazole (Hpz), 3(5)-methylpyrazole (Hmpz) or 3,5-dimethylpyrazole (Hdmpz) and PPh2(o-C6H4CHO) (Rh : L : P = 1 : 2 : 1) gives hydridoacyl complexes [RhHCl{PPh2(o-C6H4CO)}(L)2] (1). Stereoselective formation of 1-Hpz and 1-Hmpz with pyrazoles trans to hydrido and phosphorus and hydrogen bond formation with O-acyl and chlorido occur. 1-Hmpz is a mixture of two linkage isomers in a 9 : 1 ratio, with two 5-methylpyrazole ligands or with one 3- and one 5-methylpyrazole ligand, respectively. Fluxional 1-Hdmpz undergoes metallotropic tautomerization and is a mixture of equal amounts of 1a-Hdmpz and 1b-Hdmpz, with hydrido trans to pyrazole or chlorido, respectively. Complexes 1 readily exchange hydrido by chlorido to afford [RhCl2{PPh2(o-C6H4CO)}(L)2] (2-Hpz, 2-Hmpz and 2-Hdmpz) as single isomers with cis chloridos and two N–H⋯Cl hydrogen bonds. The reaction of 1 with PPh3 or PPh2OH affords static [RhHCl{PPh2(o-C6H4CO)}(PPh3)L] (3) or [RhHCl{PPh2(o-C6H4CO)}(PPh2OH)L] (4) respectively with trans P-atoms and pyrazoles forming N–H⋯Cl hydrogen bonds. 3-Hpz and 3-Hmpz contain single species with hydrido cis to chlorido, while 3-Hdmpz is a mixture of equal amounts of 3a-Hdmpz and 3b-Hdmpz. Complexes 4, with an additional O–H⋯O hydrogen bond, selectively contain only the cis-H,Cl species with all the three ligands. The reaction of [{RhCl(COD)}2] with L and PPh2(o-C6H4CHO) (Rh : L : P = 1 : 1 : 2) led to complexes with trans P-atoms, [RhHCl{PPh2(o-C6H4CO)}{PPh2(o-C6H4CHO)-κP}L] (5-Hpz, 5a-Hdmpz and 5b-Hdmpz), at room temperature, and to [RhCl{PPh2(o-C6H4CO)}{PPh2(o-C6H4CHOH)}(Hmpz)] (6-Hmpz) or [RhCl{PPh2(o-C6H4CO)}2L] (7) with hydrogen evolution in refluxing benzene. DFT calculations were used to predict the correct isomers, their ratios and the particular intramolecular hydrogen bonds in these complexes. Single crystal X-ray diffraction analysis was performed on 2-Hpz, 3a-Hdmpz and 7-Hpz. Complexes 1 are efficient homogeneous catalysts (0.5 mol% loading) in the hydrolysis of amine– or ammonia–borane (AB) to generate up to 3 equivalents of hydrogen in the presence of air.
- Published
- 2015
14. Anion controlled structural and magnetic diversity in unusual mixed-bridged polynuclear Ni(II) complexes with a versatile bis(2-methoxy phenol)diamine hexadentate ligand. An experimental and theoretical magneto-structural study
- Author
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José M. Seco, Luis Botana, Enrique Colacio, Antonio J. Mota, Itziar Oyarzabal, José Ruiz, and Antonio Rodríguez-Diéguez
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Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,Stereochemistry ,Diamine ,Cationic polymerization ,Antiferromagnetism ,Ethylenediamine ,Azide ,Mannich base ,Crystal structure ,Ground state - Abstract
This work reports the syntheses, crystal structures, magnetic properties and DFT calculations of six novel polynuclear NiII compounds [Ni2(μ-HL1)2(μ-N3)]N3·(CH3OH)2·2H2O (1), [Ni2(μ-HL1)2(μ-N3)][Na2Ni2(μ-L1)2(μ-N3)2(CH3OH)(N3)]·4CH3OH (2), [Ni4(μ-L1)2(μ-N3)4(CH3OH)2]·2CH3OH (3), [Na2Ni4(μ-L1)2(μ-OAc)2(μ-N3)4(CH3OH)4]·2CH3OH (4), [Ni4(μ-L1)2(μ-Cl)2(Cl)2] (5), and [Ni3(μ-L1)2(acac)2(H2O)2] (6), with uncommon structures and rare mixed-bridges between NiII ions, which were prepared from the versatile polytopic Mannich base ligand N,N′-dimethyl-N,N′-bis(2-hydroxy-3-methoxy-5-methylbenzyl)ethylenediamine (H2L1). The anionic coligand (azide, chloride, acetate and acetylacetonate) and reaction conditions play crucial roles in determining the final structure of these compounds and consequently their magnetic properties. Compound 1 contains a Ni2 cationic unit with rare di-μ-phenoxido/μ1,1-azide triple mixed bridges whereas complex 2 is made from the same Ni2 cationic unit as 1, cocrystallized with Na2Ni2 neutral units, in which double μ1,1,1-azide bridges connect the NiII and NaI anions. Complexes 3 and 4 are Ni4 complexes with defective dicubane and linear structures, respectively. Complex 3 has two distinct types of mixed bridges, μ-phenoxido/μ1,1,1-azido and μ1,1-azido/μ1,1,1-azido and a double di-μ1,1,1-azido bridge, the latter connecting the face-sharing NiII ions. In 4, rare μ-phenoxido/μ1,1-azide/syn–syn acetate triple mixed bridges connect central and terminal NiII atoms whereas a double μ1,1-azide planar bridging fragment links the central NiII ions. Complex 5 has a defective-dicubane structure with double μ-phenoxido/μ3-chloro mixed bridges and di-μ3-chloro bridges, whereas complex 6 has a bent structure with very uncommon single μ-phenoxido bridges. The analysis of the magnetic properties reveals that in complexes 1–4 all magnetic pathways transmit ferromagnetic interactions leading to S = 2 ground states for 1 and 2 and S = 4 ground states for 3 and 4. In complex 5, the double μ-phenoxido/μ3-chloro mixed bridges and di-μ3-chloro bridges mediate antiferro- and ferromagnetic interactions, respectively, giving rise to a S = 0 ground state. Complex 6 shows antiferromagnetic interactions between the NiII ions through single μ-phenoxido bridging groups, leading to an S = 1 ground state. DFT calculations on the X-ray structures and model compounds were performed to support the magneto-structural data of the above compounds.
- Published
- 2014
15. Efficient hydridoirida-β-diketone-catalyzed hydrolysis of ammonia- or amine-boranes for hydrogen generation in air
- Author
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Carlos Ubide, Itziar Zumeta, Antonio Rodríguez-Diéguez, Claudio Mendicute-Fierro, María A. Garralda, and José M. Seco
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Inorganic Chemistry ,chemistry.chemical_compound ,Hydrolysis ,Aniline ,chemistry ,Hydride ,Cationic polymerization ,Organic chemistry ,Amine gas treating ,Boranes ,Homogeneous catalysis ,Medicinal chemistry ,Catalysis - Abstract
The dihydridoirida-β-diketone [IrH2{(PPh2(o-C6H4CO))2H}] (2) has been used as a homogeneous catalyst for the hydrolysis of ammonia- or amine-boranes to generate up to 3 equivalents of hydrogen in the presence of air. When using 0.5 mol% loading of 2, dimethylamine-borane is hydrolysed completely within 8 min at 30 °C and maintains its activity in consecutive runs. Ammonia-borane or tert-butylamine-borane is hydrolysed completely within 32 or 25 min respectively. Triethylamine-borane fails to be hydrolysed. Kinetic studies suggest a sequence of two consecutive first-order reactions, in which an intermediate builds up and finally falls, with the first step being the rate controlling step. ΔH1(‡) are in the range 65-85 kJ mol(-1) and negative values of ΔS1(‡) are obtained. A multinuclear NMR study of the catalyzed reaction shows the formation of a resting state (A) of the active catalyst proposed to be of the hydridodiacyl type [IrH(PPh2(o-C6H4CO))2(solvent)] with a hydride trans to the acyl group. In the absence of substrate a dormant species (B) is formed. By the reaction of hydridoirida-β-diketones with ammonia, the hydridoirida-β-ketoimine [IrHCl{(PPh2(o-C6H4CO))(PPh2(o-C6H4CNH))H}] (3) and the hydridobis(acylphosphane)aminoiridium(III) complex [IrH(PPh2(o-C6H4CO))2(NH3)] (4), with a hydride trans to phosphane, are formed. Aromatic amines such as aniline or anisidines afford cationic [IrH{(PPh2(o-C6H4CO))2H}(C6H4RNH2)]ClO4 (R = H (6); p-MeO (7); o-MeO (8)) hydridoirida-β-diketones with a coordinated amine group trans to the hydride. The dormant species B is proposed to be of the hydridobis(acylphosphine)aminoiridium(III) type with a hydride trans to the amine group.
- Published
- 2013
16. Rational design of ferromagnetic coupled diphenoxocarboxylate triply bridged dinuclear nickel(II) complexes: orbital countercomplementarity of the bridging ligands
- Author
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Antonio Rodríguez-Diéguez, José M. Seco, José Ruiz, Antonio J. Mota, Enrique Colacio, and Itziar Oyarzabal
- Subjects
Ligand ,Stereochemistry ,chemistry.chemical_element ,Ion ,Inorganic Chemistry ,Nickel ,chemistry.chemical_compound ,Crystallography ,Octahedron ,chemistry ,Ferromagnetism ,Diethylenetriamine ,Antiferromagnetism ,Carboxylate - Abstract
Four new dinuclear complexes [Ni(μ-L)(μ-OAc)Ni(H2O)2]NO3 (1), Ni(μ-L)(μ-OBz)Ni(H2O)(MeOH)]NO3·3MeOH (2), [Ni(μ-L)(μ-9-An)Ni(H2O)(MeOH)]NO3 (3) and [Ni(μ-L)(μ-OAc)Ni(H2O)(N3)]·CH3OH (4) have been prepared from the compartmental ligand N,N′,N′′-trimethyl-N,N′′-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine (H2L) and different carboxylate ligands (OBz = benzoate and 9-An = 9-anthracenecarboxylate), and then magnetically and structurally characterized. The X-ray structures of these complexes reveal that the Ni2+ ions are bridged by two phenoxo groups belonging to the L2− ligand and one syn–syn carboxylate group, giving rise to diphenoxocarboxylate triply bridged dinuclear nickel(II) complexes. The syn–syn carboxylate bridging group folds the structure with hinge angles (β) in the range 32–36°. The folding of the structure takes place with a concomitant decrease of the O–Ni–O bridging angle (θ) and an increase of the shift carbon atom directly linked to the phenoxo oxygen atom with respect to the Ni–Ni–O plane in the bridging region (τ angle). All the complexes exhibit ferromagnetic interactions between the slightly distorted octahedral Ni2+ ions. A comparative analysis of the magneto-structural data for 1–4 and other diphenoxocarboxylate bridged complexes clearly show that not only the θ angle, but also the τ and β angles play a significant role in determining the sign and magnitude of the magnetic exchange coupling in these complexes. The ferromagnetic behaviour observed for 1–4 has been justified on the basis of their relatively low θ and high β and τ values, all of them decreasing the antiferromagnetic contribution in complexes 1–4, as well as the countercomplementarity effects between the diphenoxo and carboxylate bridging ligands. DFT theoretical calculations unequivocally demonstrate that the countercomplementarity mechanism is operative in compounds 1–4.
- Published
- 2012
17. Insights on the binding ability of a new adenine analog: 7-amine-1,2,4-triazolo[1,5-a]pyrimidine. Synthesis and magnetic study of the first copper(II) complexes
- Author
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Ana B. Caballero, José A. Dobado, Isaac Vidal, Luis Lezama, Oscar Castillo, Juan M. Salas, and Antonio Rodríguez-Diéguez
- Subjects
Models, Molecular ,Denticity ,Stereochemistry ,Ligand ,Adenine ,Electron Spin Resonance Spectroscopy ,chemistry.chemical_element ,Bridging ligand ,Triazoles ,Ligands ,Copper ,Oxalate ,Electron localization function ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,Malonate ,Pyrimidines ,Adenine analog ,chemistry ,Coordination Complexes - Abstract
Conventional reactions of the new multidentate ligand 7-amine-1,2,4-triazolo[1,5-a]pyrimidine (7atp, 1) with copper(II) salts lead to four novel multidimensional coordination complexes [Cu(7atp)(mal)(H(2)O)(2)]·H(2)O (2), [Cu(2)(μ-7atp)(4)(H(2)O)(2)](ClO(4))(4)·3H(2)O (3), {[Cu(7atp)(2)(μ-ox)]·3H(2)O}(n) (4) and {[Cu(7atp)(2)(μ-suc)]·2H(2)O}(n) (5), where ox(2-), mal(2-) and suc(2-) mean oxalate, malonate and succinate, respectively. In these compounds, the 7atp ligand coordinates monodentately through its atom N3, except for compound 3, which displays N3-N4 coordination mode, giving rise to all to structures with diverse topologies and dimensionality. Compound 2 is a mononuclear entity, 3 consists of dinuclear species, 4 is a zig-zag chain with oxalate as a bridging ligand and 5 is a succinate-bridged mono-dimensional system. All polynuclear metal complexes show antiferromagnetic interactions of with J values ranging from -0.12 to -49.5 cm(-1). The ligand donor capabilities have been estimated by topological analyses of the electron density (QTAIM) and electron localization function (ELF), obtained by DFT calculations. The compounds are the first structurally characterized copper(II) complexes containing the 7atp ligand.
- Published
- 2011
18. Structural and magnetic properties of three novel complexes with the versatile ligand 5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one
- Author
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Elisa Barea, Antonio Rodríguez-Diéguez, Ana B. Caballero, Luis Lezama, and Juan M. Salas
- Subjects
Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Crystallography ,Denticity ,Monomer ,Ferromagnetism ,Ligand ,Chemistry ,visual_art ,visual_art.visual_art_medium ,Antiferromagnetism - Abstract
Conventional reactions of the versatile multidentate ligand 5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one (HmtpO) with metallic(II) salts lead to three novel multidimensional complexes [Cu(HmtpO)(2)(H(2)O)(3)](ClO(4))(2)·H(2)O (1), {[Cu(HmtpO)(2)(H(2)O)(2)](ClO(4))(2)·2HmtpO}(n) (2) and {[Co(HmtpO)(H(2)O)(3)](ClO(4))(2)·2H(2)O}(n) (3). In each compound, the triazolopyrimidine ligand shows a different and unusual coordination mode, giving rise to structures with diverse topologies and dimensionality. Compound 1 is a monomeric complex, in which HmtpO shows both N3-monodentate and N1,O71-bidentate modes. 2 is a bidimensional framework with the ligand showing a N3,O71 bidentate-bridging mode. The structure of 3 consists of 1D chains, in which HmtpO displays a N1,N3,O71-tridentate-bridging mode. It should be noted that these coordination modes of the HmtpO ligand are unique in the case of compounds 2 and 3. On the other hand, the magnetic properties of the polynuclear complexes 2 and 3 have been studied showing weak ferromagnetic and antiferromagnetic behaviour, respectively.
- Published
- 2011
19. Enhanced ferromagnetic interaction in metallacyclic complexes incorporating m-phenylenediamidato bridges
- Author
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Maria A. Palacios, Antonio J. Mota, Juan Manuel Herrera, Angelo Sironi, Enrique Colacio, Antonio Rodríguez-Diéguez, and Joan Cano
- Subjects
Models, Molecular ,Stereochemistry ,Pyridines ,Metal ions in aqueous solution ,chemistry.chemical_element ,Bridging ligand ,Crystallography, X-Ray ,Ligands ,Copper ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Nickel ,Magnetics ,chemistry ,Models, Chemical ,Pyridine ,Benzene Derivatives ,Organometallic Compounds ,Molecule ,Computer Simulation ,Bimetallic strip ,Group 2 organometallic chemistry - Abstract
The double stranded Cu(II)2-metallacyclic complex of formula [Cu2(mbpb)2].2H2O (1) and the triple stranded Ni(II)2-metallacyclic complexes of formula [Ni2(Hmbpb)3]PF6.21H2O (2), [Co(H2O)6][Ni2(mbpb)3)]THF.10H2O (3) and {Ag2(H2O)[Ni2(mbpb)3]}.11H2O (4) (where H2mbpb is the bisbidentate dinucleating bridging ligand 1,3-bis(pyridine-2-carboxamide) benzene) have been synthesised and characterised by single-crystal X-ray diffraction. Within the dinuclear molecules, metal ions are bridged by either fully or semideprotonated bisbidentate ligands, which are coordinated through the pyridine and amidato nitrogen donor atoms. In complex 4 the triple stranded dinuclear Ni2 units are connected to the Ag+ cations through O-amidato bridges and Ag-pi(benzene) interactions to afford a 1D bimetallic chain. Cu2 (1) and Ni2 (2-4) complexes exhibit ferromagnetic coupling between the metal ions through the bridging ligand with J(Cu-Cu) = 21.1 cm(-1) and J(Ni-Ni) in the range of 2.9-3.6 cm(-1), respectively. Amongst copper(II) dinuclear complexes bearing m-phenylenediamidato bridges, complex 1 exhibits the stronger ferromagnetic exchange coupling reported so far. DFT calculations firstly confirm that the spin polarisation mechanism is responsible for the ferromagnetic coupling, and secondly allows us to predict stronger ferromagnetic couplings in Cu(II)(2) complexes with larger tetrahedral distortions of the CuN4 coordination environment.
- Published
- 2009
20. [Re2(micro-1,2,4-triazolate)2(micro-OH)(CO)6]-: a novel metalloligand for the construction of flexible porous coordination networks
- Author
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Giuseppe D' Alfonso, Jorge A. R. Navarro, Antonio Rodríguez-Diéguez, Elisa Barea, and Angelo Sironi
- Subjects
Models, Molecular ,Carbon Monoxide ,Materials science ,Silver ,Stereochemistry ,Surface Properties ,Triazoles ,Porous Coordination Networks ,Crystallography, X-Ray ,Ligands ,Inorganic Chemistry ,Crystallography ,Rhenium ,Coordination network ,Organometallic Compounds ,Porosity - Abstract
The [Re2(micro-trz-kappaN1:kappaN2)2(micro-OH)(CO)6]- (trz = 1,2,4-triazolate) organometallic anion reacts with Ag+ to afford a 2D organometallic/coordination network, [Ag[Re2(micro3-trz-kappaN1:kappaN2:kappaN4)2(micro3-OH)(CO)6]]n x 4nCH3OH, which shows dynamic structural changes triggered by solid-liquid guest exchange processes.
- Published
- 2008
21. Synthesis, X-ray structures and luminescence properties of three multidimensional metal-organic frameworks incorporating the versatile 5-(pyrimidyl)tetrazolato bridging ligand
- Author
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Enrique Colacio, Pablo Vitoria, Alfonso Salinas-Castillo, Antonio Rodríguez-Diéguez, Norberto Masciocchi, Simona Galli, and Juan M. Gutiérrez-Zorrilla
- Subjects
Inorganic Chemistry ,chemistry.chemical_classification ,Crystallography ,Photoluminescence ,Chemistry ,Ligand ,Hydrogen bond ,Stacking ,Metal-organic framework ,Bridging ligand ,Polymer ,Luminescence - Abstract
The hydrated sodium salt of the novel and versatile 5-(pyrimidyl)tetrazolato ligand (pmtz(-)), Na(pmtz).H(2)O (1), has been prepared in very mild conditions from 2-cyanopyrimidine and NaN(3). Two coordination polymers [Cd(pmtz)(2)]n (2)and [Cd(pmtz)(micro-Cl)(0.5)(micro-N(3))(0.5)(H(2)O)](n)(3), , have been synthesized from (1)under conventional or hydrothermal conditions, respectively, and fully characterized by single-crystal or powder X-ray diffraction methods. Compounds and consist of mono-dimensional polymeric chains, further stabilized by interchain pi-pi stacking and hydrogen bond interactions. Compound , containing octacoordinated Cd ions of crystallographic D(2) symmetry, exhibits neutral (4, 4) layers formed by square units of the metallacalix[4]arene type in 1,3-alternate conformation. Species , and display intense, room temperature, photoluminescence in the solid state.
- Published
- 2007
Catalog
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