Juan J. Fiol
Other affiliations: Spanish National Research Council
Bio: Juan J. Fiol is an academic researcher from University of the Balearic Islands. The author has contributed to research in topic(s): Ligand & Non-covalent interactions. The author has an hindex of 21, co-authored 69 publication(s) receiving 1307 citation(s). Previous affiliations of Juan J. Fiol include Spanish National Research Council.
Papers published on a yearly basis
14 Nov 2007-Inorganic Chemistry
TL;DR: In this article, a high-level ab initio study of anion−π interactions involving N9-methyl-adenine, N6methyl-adenine and N9methyl-hypoxanthine was performed and it was shown that these compounds are able to interact favorably with anions.
Abstract: In this manuscript we report a high-level ab initio study of anion−π interactions involving N9-methyl-adenine, N6-methyl-adenine, N9-methyl-hypoxanthine, a dimer of N9-methyl-adenine, and N9,N9‘-trimethylene-bisadenine. DNA bases like adenine are electron-deficient arenes that are well suited for interacting favorably with anions. We demonstrate that these compounds are able to interact favorably with anions. N9-Methyl-adenine, N6-methyl-adenine, and the dimer of N9-methyl-adenine interact with the anion via the six-membered ring more strongly than adenine due to cooperativity effects between the noncovalent π−π and anion−π interactions. This pattern, i.e., coexistence of π−π and anion−π bonding, is observed experimentally in the solid state. Finally, we report the solid-state characterization of two new compounds N6,N6‘-dimethylene-bisadenine hydrochloride and an outer-sphere complex of protonated N9,N9‘-trimethylene-bishypoxanthine with zinc tetrachloride anion, that exhibit interesting anion−π interact...
TL;DR: Three new ternary peptide-Cu(II)-1,10-phenanthroline (phen) complexes have been prepared and structurally characterised and exhibit significant differences in their nuclease activity which depends on the nature of the peptidic moiety, the complex [Cu(gly-L-trp) (phen)]2H(2)O 3 being the most active.
Abstract: Three new ternary peptide–Cu(II)–1,10-phenanthroline (phen) complexes, [Cu( l -ala–gly)(phen)]·3.5H2O 1, [Cu( l -val–gly)(phen)] 2 and [Cu(gly– l -trp)(phen)]·2H2O 3, have been prepared and structurally characterised. These compounds exist as distorted square pyramidal complexes with the five co-ordination sites occupied by the tridentate peptide dianion and the two heterocyclic nitrogens of the phenanthroline ligand. The bulk of the lateral chain in the peptide moiety determines the relative disposition of the phen ligand. Thus, in [Cu( l -val–gly)(phen)] 2, the phenanthroline plane is deviated towards the opposite side of the isopropyl group of the l -valine moiety. On the other hand, in [Cu(gly– l -trp)(phen)]·2H2O 3 the absence of stacking interactions between phen and indole rings and the presence of an intramolecular CH⋯π interaction should be pointed out. These complexes exhibit significant differences in their nuclease activity which depends on the nature of the peptidic moiety, the complex [Cu(gly– l -trp) (phen)]·2H2O 3 being the most active.
TL;DR: In low-molecular-weight ternary complexes some recognition patterns are repeatedly observed as mentioned in this paper, such as long bonds between metal ions and nucleobases, hydrogen bonds between the amino group of amino acids and a carbonyl group of the nucleobas and vice versa.
Abstract: Metal–peptide or metal–nucleoside complexes may be used as models to identify recognition patterns for nucleic acids and peptides. Zinc fingers or mer and fur proteins are also examples of ternary systems with non-direct covalent bonds towards DNA. In low-molecular-weight ternary complexes some recognition patterns are repeatedly observed. This recognition tackles with the complexity of the systems and is responsible for the extra stabilization of such complexes. Some of these recognition patterns are: (a) long bonds between metal ions and nucleobases; (b) hydrogen bonds between the amino group of amino acids and a carbonyl group of the nucleobases and vice versa; (c) hydrogen bonds between a coordinated water molecule and one of the ligands; (d) stacking between nucleobases and aromatic ring or hydrophobic residues of amino acids; (e) possible direct d–π interactions between metal ions and aromatic rings, as well as CH⋯π interactions and other odd recognition patterns that can still be rationalized.
30 Apr 2000-Polyhedron
TL;DR: In this paper, the X-ray crystal structures of [Hg(sulfamethoxypyridazinato)2] (2a), [Cd(Sulfadimitriou)2(H2O)] (4b) and [Zn(methoxazolato) 2(py)2.2(h2O)2 (6d) have been determined.
Abstract: Hg(II), Cd(II) and Zn(II) complexes with the ligands sulfadimethoxine, sulfamethoxypyridazine, sulfadiazine, sulfamerazine, sulfadimidine and sulfamethoxazole have been prepared and characterised by spectral data. 1H and 13C NMR have been used to interpret the structural characteristics of the complexes in solution. The X-ray crystal structures of [Hg(sulfamethoxypyridazinato)2] (2a), [Cd(sulfadimidinato)2(H2O)]·2H2O (4b) and [Zn(sulfamethoxazolato)2(py)2(H2O)2] (6d) have been determined. In complex 2a the Hg(II) ion lies on an inversion centre and exhibits linear coordination by two sulfonamidic nitrogen atoms [Hg–N(1)=2.071(4) A] of the two deprotonated sulfamethoxypyridazinato ligands. The polymeric Cd(II) complex (4b) exhibits a high distorted-octahedral geometry, involving the sulfonamidic nitrogen [Cd–N(1)=2.328(6); Cd–N(1′)=2.326(6) A] and the heterocyclic N(3)/N(2′) [Cd–N(3)=2.307(6) A; Cd–N(2′)=2.426(6) A] of two bidentate sulfadimidine ligands, the terminal amino N(4′b) [Cd–N(4′b)=2.379(7) A] of a third sulfadimidine which is bonded to an adjacent Cd(II), and the O(3) atom of a coordinated water molecule [Cd–O(3)=2.334(6) A]. In complex 6d the geometry around the Zn(II) ion can be described as a slightly distorted compressed octahedron. Two pyridine [Zn–N(16)=2.1841(17) A] and two isoxazole N atoms [Zn–N(2)=2.1736(15) A] are located in the equatorial plane and two oxygen atoms of two water molecules [Zn–O(4)=2.0984(14) A] are placed in the apical positions. IR and NMR spectral studies suggest a similar behaviour of the Cd(II) and Zn(II) complexes, both in solid state and solution, and different to the corresponding Hg(II) complexes. Thus 1H and 13C NMR spectra, in DMSO-d6, of Cd(II) and Zn(II) compounds show coordination mainly through the heterocyclic nitrogen while the corresponding Hg(II) derivatives seem to be coordinated through the sulfonamidic nitrogen.
22 Jan 1999-Polyhedron
TL;DR: In this paper, the crystal structures of the complexes [Cu(Sal-Ser), H2O] and [2-amino pyridine] have been determined and their crystal structures determined.
Abstract: The complexes [Cu(Sal–( L -Ser))H2O]⋅H2O 1 and [Cu(Sal–Ser)(2-amino pyridine)] 2 have been prepared and their crystal structures determined. In 1 the copper(II) has a square-pyramidal geometry, being coordinated to the tridentate Sal–( L -Ser) Schiff base ligand and the oxygen atom (O(16)) of one water molecule occupying the corners of a square. The coordination sphere about the copper is completed by an axial O(12) atom of an hydroxyl group belonging to an adjacent complex unit. In the racemic ternary complex 2 the metal atom has a square-planar coordination with O,N,O atoms of the tridentate Sal–Ser dianion and the heterocyclic N atom of the 2-aminopyridine. Spectroscopic data are discussed.
11 May 2004-CrystEngComm
TL;DR: The CH/π interaction is a kind of hydrogen bond operating between a soft acid CH and a soft base π-system (double and triple bonds, C6 and C5 aromatic rings, heteroaromatics, convex surfaces of fullerenes and nanotubes) as discussed by the authors.
Abstract: The nature and characteristics of the CH/π interaction are discussed by comparison with other weak molecular forces such as the CH/O and OH/π interaction. The CH/π interaction is a kind of hydrogen bond operating between a soft acid CH and a soft base π-system (double and triple bonds, C6 and C5 aromatic rings, heteroaromatics, convex surfaces of fullerenes and nanotubes). The consequences of CH/π hydrogen bonds in supramolecular chemistry are reviewed on grounds of recent crystallographic findings and database analyses. The topics include intramolecular interactions, crystal packing (organic and organometallic compounds), host/guest complexes (cavity-type inclusion compounds of cyclodextrins and synthetic macrocyclic hosts such as calixarenes, catenanes, rotaxanes and pseudorotaxanes), lattice-inclusion type clathrates (including liquid crystals, porphyrin derivatives, cyclopentadienyl compounds and C60 fullerenes), enantioselective clathrate formation, catalytic enantioface discriminating reactions and solid-state photoreaction. The implications of the CH/π concept for crystal engineering and drug design are evident.
16 May 2011-Angewandte Chemie
TL;DR: This review describes a multidimensional treatment of molecular recognition phenomena involving aromatic rings in chemical and biological systems that facilitates the development of new advanced materials and supramolecular systems, and should inspire further utilization of interactions with aromatic rings to control the stereochemical outcome of synthetic transformations.
Abstract: This review describes a multidimensional treatment of molecular recognition phenomena involving aromatic rings in chemical and biological systems. It summarizes new results reported since the appearance of an earlier review in 2003 in host-guest chemistry, biological affinity assays and biostructural analysis, data base mining in the Cambridge Structural Database (CSD) and the Protein Data Bank (PDB), and advanced computational studies. Topics addressed are arene-arene, perfluoroarene-arene, S⋅⋅⋅aromatic, cation-π, and anion-π interactions, as well as hydrogen bonding to π systems. The generated knowledge benefits, in particular, structure-based hit-to-lead development and lead optimization both in the pharmaceutical and in the crop protection industry. It equally facilitates the development of new advanced materials and supramolecular systems, and should inspire further utilization of interactions with aromatic rings to control the stereochemical outcome of synthetic transformations.
07 Jan 2012-Chemical Society Reviews
TL;DR: This critical review covers advances in anion complexation in the year 2010 and highlights the applications to which anion receptors can be applied such as sensing, anion transport, control of molecular motion and gelation.
Abstract: This critical review covers advances in anion complexation in the year 2010. The review covers both organic and inorganic systems and also highlights the applications to which anion receptors can be applied such as sensing, anion transport, control of molecular motion and gelation (179 references).
04 Oct 2011-Angewandte Chemie
TL;DR: The objectives of this Review are to discuss current thinking on the nature of this interaction, to survey key experimental work in which anions-π bonding is demonstrated, and to provide insights into the directional nature of anion-π contact in X-ray crystal structures.
Abstract: Supramolecular chemistry is a field of scientific exploration that probes the relationship between molecular structure and function. It is the chemistry of the noncovalent bond, which forms the basis of highly specific recognition, transport, and regulation events that actuate biological processes. The classic design principles of supramolecular chemistry include strong, directional interactions like hydrogen bonding, halogen bonding, and cation-π complexation, as well as less directional forces like ion pairing, π-π, solvophobic, and van der Waals potentials. In recent years, the anion-π interaction (an attractive force between an electron-deficient aromatic π system and an anion) has been recognized as a hitherto unexplored noncovalent bond, the nature of which has been interpreted through both experimental and theoretical investigations. The design of selective anion receptors and channels based on this interaction represent important advances in the field of supramolecular chemistry. The objectives of this Review are 1) to discuss current thinking on the nature of this interaction, 2) to survey key experimental work in which anion-π bonding is demonstrated, and 3) to provide insights into the directional nature of anion-π contact in X-ray crystal structures.