Leire Felices - Academia.edu (original) (raw)
Papers by Leire Felices
Polyoxotungstates constitute a large class of anionic tungsten-oxide clusters with rich solution ... more Polyoxotungstates constitute a large class of anionic tungsten-oxide clusters with rich solution chemistry, highly diverse topologies and numerous applications in key areas within the materials science. These clusters have been thoroughly reacted with lanthanoids, and in the specific case of cerium, it is only in the last decade that a significant increase in the number of structurally characterized ceriopolyoxotungstates is observed despite of the fact that the first structural report on such compounds dates from the early seventies. Cerium has primarily been combined with lacunary polyoxotungstates acting as polydentate O-donor rigid ligands to generate a variety of molecular assemblies. These range from several small 1:2 sandwich-type clusters or 1:1 monomeric building blocks derived as dimers or chains to some giant, nanosized ceriopolyoxotungstates that contain over fifteen cerium and one hundred tungsten atoms per cluster and are amongst the largest polyoxotungstates known. Be...
The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exh... more The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exhibiting a distorted octahedral coordination geometry. The equatorial plane is formed by two N,O-bidentate 1H-imidazole-4-carboxylate ligands and the axial positions are occupied by water molecules. The crystal packing consists of a three-dimensional network stabilized by O—H···O and N—H···O hydrogen bonds, together with weak π–π interactions [centroid–centroid distance = 3.577 (2) A ° ] between the imidazole rings
![Research paper thumbnail of Diaquabis(1H-imidazole-4-carboxylato-[kappa]2N3,O)cobalt(II)](https://attachments.academia-assets.com/40105652/thumbnails/1.jpg)
](Acta Crystallographica Section E Structure Reports Online
The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exh... more The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exhibiting a distorted octahedral coordination geometry. The equatorial plane is formed by two N,O-bidentate 1H-imidazole-4-carboxylate ligands and the axial positions are occupied by water molecules. The crystal packing consists of a three-dimensional network stabilized by O—H⋯O and N—H⋯O hydrogen bonds, together with weak π–π interactions [centroid–centroid distance = 3.577 (2) Å] between the imidazole rings.
Functionalization of polyoxometalates (POMs) via covalent attachment of organic ligands represent... more Functionalization of polyoxometalates (POMs) via covalent attachment of organic ligands represents a suitable strategy to obtain hybrid derivatives of this class of anionic clusters with new properties and applications. Several routes have been explored to prepare such hybrids, including ligand substitution of labile water molecules on 3d-substituted POMs. Despite of being ideal candidates because of their two external 3d atoms with three water molecules each, Krebs-type [M2(H2O)6(WO2)2(XW9O33)2]n- polyoxotungstates remain almost unexplored as POM precursors in ligand substitution and only oxalate derivatives of iron(III) tetra-substituted clusters are known. Here we report the direct functionalization of 3d-disubstituted Krebs-type POMs with 4-imidazolecarboxylate (L), which has resulted in two complete families of organically derivatized [{MII(L)(H2O)}2(WO2)2(XW9O33)2]12- tungstoantimonate(III) and –bismuthate(III) species, where M=Mn, Co, Ni, Zn. The title POMs have been prepared...
The title compound, [Co(C5H3N2O2)2(H2O)2]·2H2O, contains a CoII ion on an inversion center, exhib... more The title compound, [Co(C5H3N2O2)2(H2O)2]·2H2O, contains a CoII ion on an inversion center, exhibiting an octahedral coordination geometry. The equatorial plane is formed by two trans-related N,O-bidentate pyridazine-3-carboxylate ligands and the axial positions are occupied by two water molecules. The CoII complex molecules are stacked in a column along the a-axis direction by an O—H···N hydrogen bond between the non-coordinating pyridazine N atom and the coordinating water molecule. These columns are further connected into a layer parallel to the ac plane by additional hydrogen bonds involving the coordinating and non-coordinating water molecules, and the non-coordinating carboxylate O atom. The crystal packing is completed by interlayer weak C—H···O interactions.
Inorganic Chemistry
A systematic study on the organic functionalization of a well-known family of 3d-metal-substitute... more A systematic study on the organic functionalization of a well-known family of 3d-metal-substituted polyoxometalate clusters is reported. Functionalization is achieved by performing classical coordination chemistry on the exposed 3d-metal centers with a series of N,O-chelating ligands, with different behaviors seen for related ligands. See B. Artetxe, S. Reinoso, L. San Felices, P. Vitoria, A. Pache, J. Martín-Caballero, and J. M. Gutiérrez-Zorrilla, page 241
CrystEngComm, 2015
ABSTRACT The porous hybrid metavanadate [{Cu(cyclam)}(VO3)2]•5H2O (1) (cyclam = 1,4,8,11–tetraaza... more ABSTRACT The porous hybrid metavanadate [{Cu(cyclam)}(VO3)2]•5H2O (1) (cyclam = 1,4,8,11–tetraazacyclotetradecane) undergoes thermally triggered sequential single–crystal–to–single–crystal (SCSC) transformations upon gradual dehydration to produce three new porous crystalline phases, namely [{Cu(cyclam)}(VO3)2]•3H2O (2), [{Cu(cyclam)}(VO3)2]•1.3H2O (3) and [{Cu(cyclam)}(VO3)2] (4). Compound 1 consists in a three–dimensional structure formed by metavanadate chains linked by {Cu(cyclam)} moieties in a hybrid open framework with two different types of hexagonal channels where water molecules of hydration are hosted. The SCSC transformations cause a rearrangement of the metavanadate chains in such a way that they contract when going from 1 to 2 and stretch back when 2 transforms into 3. The size of the channels is also modified as the hybrid dehydrates. The transition from 2 to 3 produces the cleavage of a Cu–O bond and consequent coordination of a {Cu(cyclam)} moiety to a different {VO4} unit, which drastically decreases the size of the channel in the process. In contrast, total dehydration of 3 enlarges the channel in the anhydrous phase 4 due to the migration of another Cu atom. The reversibility of such transformations has been monitored by a combination of thermogravimetric and powder X–ray diffraction analyses. While 1 and 3 are stable in open–air conditions, 2 transforms back into 1 upon being exposed to air for three weeks. The anhydrous phase 4 rapidly rehydrates into 3 in contact with ambient moisture. Furthermore, 3 can also be transformed into the parent hybrid 1 when soaked in water for seven days. Therefore, all crystal transitions described herein are fully reversible by applying the appropriate conditions.
Inorganic Chemistry, 2009
Zinc(II) salphen complexes equipped with additional alkoxy donor groups at the 3-position of the ... more Zinc(II) salphen complexes equipped with additional alkoxy donor groups at the 3-position of the salicylideneimine groups have been prepared to bind metal acetates in a second coordination sphere close to the central Zn(II) ion. The isolated binuclear monosalphen complexes have been studied in detail using NMR and MS techniques. Further synthesis has revealed that the formation of binuclear species from the parent salphen ligands is dependent on the nature of the bridging group between the two salicylideneimine groups and is prevented by replacement of one of the alkoxy substituents for a bulky t-Bu group. One of the binuclear Zn2 complexes was crystallographically characterized and can be regarded as a structural model for the intermediate stage of the transmetalation of the central Zn(II) center within these dinuclear compounds by other metal acetate salts. Furthermore, the X-ray diffraction structure also relates well with some intermediate structural stages of the buildup of various polynuclear salen structures.
Inorganics, 2015
Three new hybrid inorganic-metalorganic compounds containing Keggin-type polyoxometalates, neutra... more Three new hybrid inorganic-metalorganic compounds containing Keggin-type polyoxometalates, neutral copper(II)-picolinate complexes and guanidinium cations have been synthesized in bench conditions and characterized by elemental analysis, infrared spectroscopy and single-crystal X-ray diffraction: the isostructural [C(NH2)3]4[{XW12O40}{Cu2(pic)4}]·[Cu2(pic)4(H2O)]2·6H2O [X = Si (1), Ge (3)] and [C(NH2)3]8[{SiW12O40}2{Cu(pic)2}3{Cu2(pic)4(H2O)}2]·8H2O (2). The three compounds show a pronounced two-dimensional character owing to the structure-directing role of guanidinium. In 1 and 3, layers of [{XW12O40}{Cu2(pic)4}]n 4n− hybrid POM chains and layers of [Cu2(pic)4(H2O)] complexes and [C(NH2)3] + cations pack alternately along the z axis. The hydrogen-bonding network established by guanidinium leads to a trihexagonal tiling arrangement of all copper(II)-picolinate species. In contrast, layers of [C(NH2)3] + -linked [{SiW12O40}2{Cu(pic)2}3]n 8n− double chains where each Keggin cluster displays a {Cu2(pic)4(H2O)} moiety pointing at the intralamellar space are observed in 2. OPEN ACCESS Inorganics 2015, 3 195
Chemistry - A European Journal, 2015
Polyoxometalates The reaction of early lanthanides, GeO2 , and Na2 WO4 in buffered medium was sys... more Polyoxometalates The reaction of early lanthanides, GeO2 , and Na2 WO4 in buffered medium was systematically studied and a series of hexameric and dodecameric polyoxometalates with a closely related crown-shaped framework based on [Ln2 GeW10 O38 ](6-) Keggin-type subunits was isolated. The dodecamers represent the first macroions with dual behavior in the formation of vesicle-like structures that lead to different supramolecular assemblies in terms of composition and size by a solvent-triggered skeletal modification of the species undergoing self-association. For more details, see the Full Paper by S. Reinoso et al. on page 7736 ff.
Polyoxotungstates constitute a large class of anionic tungsten-oxide clusters with rich solution ... more Polyoxotungstates constitute a large class of anionic tungsten-oxide clusters with rich solution chemistry, highly diverse topologies and numerous applications in key areas within the materials science. These clusters have been thoroughly reacted with lanthanoids, and in the specific case of cerium, it is only in the last decade that a significant increase in the number of structurally characterized ceriopolyoxotungstates is observed despite of the fact that the first structural report on such compounds dates from the early seventies. Cerium has primarily been combined with lacunary polyoxotungstates acting as polydentate O-donor rigid ligands to generate a variety of molecular assemblies. These range from several small 1:2 sandwich-type clusters or 1:1 monomeric building blocks derived as dimers or chains to some giant, nanosized ceriopolyoxotungstates that contain over fifteen cerium and one hundred tungsten atoms per cluster and are amongst the largest polyoxotungstates known. Be...
The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exh... more The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exhibiting a distorted octahedral coordination geometry. The equatorial plane is formed by two N,O-bidentate 1H-imidazole-4-carboxylate ligands and the axial positions are occupied by water molecules. The crystal packing consists of a three-dimensional network stabilized by O—H···O and N—H···O hydrogen bonds, together with weak π–π interactions [centroid–centroid distance = 3.577 (2) A ° ] between the imidazole rings
Acta Crystallographica Section E Structure Reports Online
The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exh... more The title compound, [Co(C4H3N2O2)2(H2O)2], contains a CoII cation on a twofold rotation axis, exhibiting a distorted octahedral coordination geometry. The equatorial plane is formed by two N,O-bidentate 1H-imidazole-4-carboxylate ligands and the axial positions are occupied by water molecules. The crystal packing consists of a three-dimensional network stabilized by O—H⋯O and N—H⋯O hydrogen bonds, together with weak π–π interactions [centroid–centroid distance = 3.577 (2) Å] between the imidazole rings.
Functionalization of polyoxometalates (POMs) via covalent attachment of organic ligands represent... more Functionalization of polyoxometalates (POMs) via covalent attachment of organic ligands represents a suitable strategy to obtain hybrid derivatives of this class of anionic clusters with new properties and applications. Several routes have been explored to prepare such hybrids, including ligand substitution of labile water molecules on 3d-substituted POMs. Despite of being ideal candidates because of their two external 3d atoms with three water molecules each, Krebs-type [M2(H2O)6(WO2)2(XW9O33)2]n- polyoxotungstates remain almost unexplored as POM precursors in ligand substitution and only oxalate derivatives of iron(III) tetra-substituted clusters are known. Here we report the direct functionalization of 3d-disubstituted Krebs-type POMs with 4-imidazolecarboxylate (L), which has resulted in two complete families of organically derivatized [{MII(L)(H2O)}2(WO2)2(XW9O33)2]12- tungstoantimonate(III) and –bismuthate(III) species, where M=Mn, Co, Ni, Zn. The title POMs have been prepared...
The title compound, [Co(C5H3N2O2)2(H2O)2]·2H2O, contains a CoII ion on an inversion center, exhib... more The title compound, [Co(C5H3N2O2)2(H2O)2]·2H2O, contains a CoII ion on an inversion center, exhibiting an octahedral coordination geometry. The equatorial plane is formed by two trans-related N,O-bidentate pyridazine-3-carboxylate ligands and the axial positions are occupied by two water molecules. The CoII complex molecules are stacked in a column along the a-axis direction by an O—H···N hydrogen bond between the non-coordinating pyridazine N atom and the coordinating water molecule. These columns are further connected into a layer parallel to the ac plane by additional hydrogen bonds involving the coordinating and non-coordinating water molecules, and the non-coordinating carboxylate O atom. The crystal packing is completed by interlayer weak C—H···O interactions.
Inorganic Chemistry
A systematic study on the organic functionalization of a well-known family of 3d-metal-substitute... more A systematic study on the organic functionalization of a well-known family of 3d-metal-substituted polyoxometalate clusters is reported. Functionalization is achieved by performing classical coordination chemistry on the exposed 3d-metal centers with a series of N,O-chelating ligands, with different behaviors seen for related ligands. See B. Artetxe, S. Reinoso, L. San Felices, P. Vitoria, A. Pache, J. Martín-Caballero, and J. M. Gutiérrez-Zorrilla, page 241
CrystEngComm, 2015
ABSTRACT The porous hybrid metavanadate [{Cu(cyclam)}(VO3)2]•5H2O (1) (cyclam = 1,4,8,11–tetraaza... more ABSTRACT The porous hybrid metavanadate [{Cu(cyclam)}(VO3)2]•5H2O (1) (cyclam = 1,4,8,11–tetraazacyclotetradecane) undergoes thermally triggered sequential single–crystal–to–single–crystal (SCSC) transformations upon gradual dehydration to produce three new porous crystalline phases, namely [{Cu(cyclam)}(VO3)2]•3H2O (2), [{Cu(cyclam)}(VO3)2]•1.3H2O (3) and [{Cu(cyclam)}(VO3)2] (4). Compound 1 consists in a three–dimensional structure formed by metavanadate chains linked by {Cu(cyclam)} moieties in a hybrid open framework with two different types of hexagonal channels where water molecules of hydration are hosted. The SCSC transformations cause a rearrangement of the metavanadate chains in such a way that they contract when going from 1 to 2 and stretch back when 2 transforms into 3. The size of the channels is also modified as the hybrid dehydrates. The transition from 2 to 3 produces the cleavage of a Cu–O bond and consequent coordination of a {Cu(cyclam)} moiety to a different {VO4} unit, which drastically decreases the size of the channel in the process. In contrast, total dehydration of 3 enlarges the channel in the anhydrous phase 4 due to the migration of another Cu atom. The reversibility of such transformations has been monitored by a combination of thermogravimetric and powder X–ray diffraction analyses. While 1 and 3 are stable in open–air conditions, 2 transforms back into 1 upon being exposed to air for three weeks. The anhydrous phase 4 rapidly rehydrates into 3 in contact with ambient moisture. Furthermore, 3 can also be transformed into the parent hybrid 1 when soaked in water for seven days. Therefore, all crystal transitions described herein are fully reversible by applying the appropriate conditions.
Inorganic Chemistry, 2009
Zinc(II) salphen complexes equipped with additional alkoxy donor groups at the 3-position of the ... more Zinc(II) salphen complexes equipped with additional alkoxy donor groups at the 3-position of the salicylideneimine groups have been prepared to bind metal acetates in a second coordination sphere close to the central Zn(II) ion. The isolated binuclear monosalphen complexes have been studied in detail using NMR and MS techniques. Further synthesis has revealed that the formation of binuclear species from the parent salphen ligands is dependent on the nature of the bridging group between the two salicylideneimine groups and is prevented by replacement of one of the alkoxy substituents for a bulky t-Bu group. One of the binuclear Zn2 complexes was crystallographically characterized and can be regarded as a structural model for the intermediate stage of the transmetalation of the central Zn(II) center within these dinuclear compounds by other metal acetate salts. Furthermore, the X-ray diffraction structure also relates well with some intermediate structural stages of the buildup of various polynuclear salen structures.
Inorganics, 2015
Three new hybrid inorganic-metalorganic compounds containing Keggin-type polyoxometalates, neutra... more Three new hybrid inorganic-metalorganic compounds containing Keggin-type polyoxometalates, neutral copper(II)-picolinate complexes and guanidinium cations have been synthesized in bench conditions and characterized by elemental analysis, infrared spectroscopy and single-crystal X-ray diffraction: the isostructural [C(NH2)3]4[{XW12O40}{Cu2(pic)4}]·[Cu2(pic)4(H2O)]2·6H2O [X = Si (1), Ge (3)] and [C(NH2)3]8[{SiW12O40}2{Cu(pic)2}3{Cu2(pic)4(H2O)}2]·8H2O (2). The three compounds show a pronounced two-dimensional character owing to the structure-directing role of guanidinium. In 1 and 3, layers of [{XW12O40}{Cu2(pic)4}]n 4n− hybrid POM chains and layers of [Cu2(pic)4(H2O)] complexes and [C(NH2)3] + cations pack alternately along the z axis. The hydrogen-bonding network established by guanidinium leads to a trihexagonal tiling arrangement of all copper(II)-picolinate species. In contrast, layers of [C(NH2)3] + -linked [{SiW12O40}2{Cu(pic)2}3]n 8n− double chains where each Keggin cluster displays a {Cu2(pic)4(H2O)} moiety pointing at the intralamellar space are observed in 2. OPEN ACCESS Inorganics 2015, 3 195
Chemistry - A European Journal, 2015
Polyoxometalates The reaction of early lanthanides, GeO2 , and Na2 WO4 in buffered medium was sys... more Polyoxometalates The reaction of early lanthanides, GeO2 , and Na2 WO4 in buffered medium was systematically studied and a series of hexameric and dodecameric polyoxometalates with a closely related crown-shaped framework based on [Ln2 GeW10 O38 ](6-) Keggin-type subunits was isolated. The dodecamers represent the first macroions with dual behavior in the formation of vesicle-like structures that lead to different supramolecular assemblies in terms of composition and size by a solvent-triggered skeletal modification of the species undergoing self-association. For more details, see the Full Paper by S. Reinoso et al. on page 7736 ff.