Papers by Francisco Martínez-martínez
Journal of the Brazilian Chemical Society, 2014
The synthesis, density functional theory (DFT) molecular structure and Fourier transform infrared... more The synthesis, density functional theory (DFT) molecular structure and Fourier transform infrared spectroscopy (FTIR) molecular recognition study of diethyl phenylenebis(methylene) dicarbamates with 1,2-and 1,3-benzenediols is described. The formation of the complexes was confirmed by the shift of the O-H stretching bands in the IR spectra of the complexes compared with the IR spectra of the noncomplexed benzenediols.
Molecules, 2010
The thermal [4+2] cycloadditions of 3-acetyl-, 3-carbamoyl, and 3-ethoxycarbonylcoumarins with 2,... more The thermal [4+2] cycloadditions of 3-acetyl-, 3-carbamoyl, and 3-ethoxycarbonylcoumarins with 2,3-dimethyl-1,3-butadiene under solvent free conditions are reported, as well as the epoxidation reactions of some adducts. Discussion is focused on the structural features of the Diels-Alder adducts and their epoxides, based upon NMR, X-ray, and mass spectral data, and supported by ab initio theoretical calculations.
Molecules, 2010
In vitro antioxidant activity for 12 stannoxanes derived from Ph 3 SnCl (compounds 1-3), Ph 2 SnC... more In vitro antioxidant activity for 12 stannoxanes derived from Ph 3 SnCl (compounds 1-3), Ph 2 SnCl 2 (compounds 4-6), Bu 3 SnCl (compounds 7-9), and Bu 2 SnCl 2 (compounds 10-12), was assayed qualitatively by the chromatographic profile with 1,1diphenyl-2-picrylhydrazil (DPPH) method and by two quantitative methods: the DPPH radical scavenging activity and Ferric-Reducing Antioxidant Power (FRAP) assays. The results were compared with those obtained with the starting materials 2-pyridinecarboxylic acid (I), 3-pyridinecarboxylic acid (II) and 4-pyridinecarboxylic acid (III), as well as with standard compounds, such as vitamin C and vitamin E, respectively. The in vitro antiradical activity with DPPH of diphenyltin derivative 5 showed a very similar behavior to vitamin C at a 20 g/mL concentration, whereas according to the FRAP method, compound 8 was better. This difference is due to the mechanism of the antioxidant process. The Structure-Activity Relationships (SAR) for both methods is also reported.
A new cocrystal salt of metformin, an antidiabetic drug, and N,N’-(1,4-phenylene)dioxalamic acid,... more A new cocrystal salt of metformin, an antidiabetic drug, and N,N’-(1,4-phenylene)dioxalamic acid, was synthesized by mechanochemical synthesis, purified by crystallization from solution and characterized by single X-ray crystallography. The structure revealed a salt-type cocrystal composed of one dicationic metformin unit, two monoanionic units of the acid and four water molecules namely H2Mf(HpOXA)2∙4H2O. X-ray powder, IR, 13C-CPMAS, thermal and BET adsorption-desorption analyses were performed to elucidate the structure of the molecular and supramolecurar structure of the anhydrous microcrystalline mesoporous solid H2Mf(HpOXA)2. The results suggest that their structures, conformation and hydrogen bonding schemes are very similar between them. To the best of our knowledge, the selective formation of the monoanion HpOXA⁻, as well as its structure in the solid, is herein reported for the first time. Regular O(-)∙∙∙C(), O(-)∙∙∙N+ and bifacial O(-)∙∙∙C()∙∙∙O(-) of n→* charge-a...
Propylsulfonic acid grafted on mesoporous siliceous FDU-5 material: A high TOF catalyst for the synthesis of coumarins via Pechmann condensation
Microporous and Mesoporous Materials
Journal of the Mexican Chemical Society, 2001
Dedicado al Profesor Fernando Walls Armijo en su 70 aniversario Resumen. En este trabajo se descr... more Dedicado al Profesor Fernando Walls Armijo en su 70 aniversario Resumen. En este trabajo se describe la síntesis y el estudio estructural en solución, de las sulfonilureas N-[4-[2-(2-oxo-2H-1-benzopiranil-3-carboxamidil)etil]bencensulfonil]-N'-ciclohexilurea (5a) y N-[4-[2-(4-nitrobenzamidil)etil]bencensulfonil]-N'-ciclohexilurea (5b). Se realizó la asignación completa de las señales de RMN de 1 H y 13 C de los intermediarios 1-4. El compuesto 5a es un compuesto nuevo con actividad farmacológica potencial. Palabras clave: Sulfonilurea, estudio por RMN de 1 H y 13 C.
Carbonyl–carbonyl interactions and amide π-stacking as the directing motifs of the supramolecular assembly of ethyl N -(2-acetylphenyl)oxalamate in a synperiplanar conformation
Acta Crystallographica Section C Structural Chemistry, 2015
The title compound, C12H13NO4, is one of the few examples that exhibits asynconformation between ... more The title compound, C12H13NO4, is one of the few examples that exhibits asynconformation between the amide and ester carbonyl groups of the oxalyl group. This conformation allows the engagement of the amide H atom in an intramolecular three-centred hydrogen-bondingS(6)S(5) motif. The compound is self-assembled by C=O...C=O and amide–π interactions into stacked columns along theb-axis direction. The concurrence of both interactions seems to be responsible for stabilizing the observedsynconformation between the carbonyl groups. The second dimension, along thea-axis direction, is developed by soft C—H...O hydrogen bonding. Density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) level of theory were performed to support the experimental findings.
Three-center intramolecular hydrogen bonding in oxamide derivatives. NMR and X-ray diffraction study
Journal of the Chemical Society, Perkin Transactions 2, 1998
This contribution describes the synthesis and structural investigation of the symmetric and non-s... more This contribution describes the synthesis and structural investigation of the symmetric and non-symmetric oxamides N,N -bis(2-hydroxyphenyl)oxamide 1, N,N -bis(5-tert-butyl-2-hydroxyphenyl )- oxamide 2, N,N -bis(3,5-dimethyl-2-hydroxyphenyl)oxamide 3, N,N ...
Acta Crystallographica Section C Crystal Structure Communications, 2007
Acta Crystallographica Section C Crystal Structure Communications, 2008
Ethyl ( E )-3-(2-hydroxyphenyl)-2-(morpholinocarbonyl)propenoate
Acta Crystallographica Section C Crystal Structure Communications, 2004
The title compound, C16H19NO5, crystallizes as a centrosymmetric dimer through strong O-H...O hyd... more The title compound, C16H19NO5, crystallizes as a centrosymmetric dimer through strong O-H...O hydrogen-bonding interactions between the hydroxyphenyl and morpholinocarbonyl groups. The morpholinocarbonyl group is almost perpendicular to the propenoate moiety. Electron delocalization in the N-C(=O) fragment leads to the formation of hydrogen-bonded S(5) ring motifs through C-H...O interactions.
Acta Crystallographica Section C Crystal Structure Communications, 2004
Facial π...Cl...π interactions as the directing motif of the supramolecular structures of Mg 2+ and Ca 2+ bis[hydrotris(pyrazolyl)borate] chloroform disolvates
Acta Crystallographica Section C Crystal Structure Communications, 2006
ABSTRACT The isomorphous complexes bis[hydrotris(pyrazolyl)borato]magnesium(II) chloroform... more ABSTRACT The isomorphous complexes bis[hydrotris(pyrazolyl)borato]magnesium(II) chloroform disolvate, [Mg(C9H10BN6)2]·2CHCl3, and bis[hydrotris(pyrazolyl)borato]calcium(II) chloroform disolvate, [Ca(C9H10BN6)2]·2CHCl3, crystallize in the cubic space group Pa with Z = 4. The metal atoms occupy sites of symmetry, and their coordination is very similar to that found for the unsolvated Mg[HB(Pz)3]2 and Ca[HB(Pz)3]2 complexes (Pz is pyrazole). The inclusion of chloroform molecules on threefold rotation axes not only leads to high-symmetry crystal structures but also plays an important role in stabilizing the three-dimensional supramolecular architecture through facial Pz⋯Cl⋯Pz interactions.
Further insight into three center hydrogen bonding. Participation in tautomeric equilibria of heterocyclic amides
Journal of the Chemical Society, Perkin Transactions 2, 2001
In this work the synthesis and characterization in solution and solid state of three heterocyclic... more In this work the synthesis and characterization in solution and solid state of three heterocyclic oxamides and four amides capable of forming three center hydrogen bond (THB) interactions is described. The formation of THBs in solution was established and ...
2-Amino-1,3-benzothiazole–ethyl coumarin-3-carboxylate (1/1)
Acta Crystallographica Section C Crystal Structure Communications, 2003
The title adduct, C(7)H(6)N(2)S.C(12)H(10)O(4), is formed via N-H.O and N-H.N hydrogen-bonding in... more The title adduct, C(7)H(6)N(2)S.C(12)H(10)O(4), is formed via N-H.O and N-H.N hydrogen-bonding interactions, which generate a tetrameric unit with a pseudo-centre of symmetry. The tetramer further packs through parallel-displaced pi-pi stacking interactions along the a direction.
Ethyl N -phenyloxamate
Acta Crystallographica Section C Crystal Structure Communications, 2003
The oxamate group in the title compound, C(10)H(11)NO(3), is almost coplanar with the phenyl ring... more The oxamate group in the title compound, C(10)H(11)NO(3), is almost coplanar with the phenyl ring because of intramolecular hydrogen-bonding interactions, and the structure can be described as an anilide single bonded to an ethyl carboxylate group. The supramolecular structure is achieved through intermolecular hard N-H...O and soft C-H...X (X = O and phenyl) hydrogen-bonding interactions.
Diethyl piperazine-1,4-diyldioxalate
Acta Crystallographica Section C Crystal Structure Communications, 2004
The ethyl oxamate group, N-C(O)-C(O)-OEt, in the title compound, alternatively called diethyl N,N... more The ethyl oxamate group, N-C(O)-C(O)-OEt, in the title compound, alternatively called diethyl N,N':N,N'-bis(ethylene)dioxamate, C12H18N2O6, can be considered as being composed of two singly bonded amide and ester functionalities. The ethyl oxamate group is not planar. The two carbonyl groups are almost perpendicular, with an oxalyl O=C-C=O torsion angle of -111.34 (17) degrees. The molecule is located on an inversion centre. Infinite supramolecular tapes, propagating along the b axis, are formed through soft C-H...O interactions which form a centrosymmetric R(2)2(12) motif.
ChemInform, 2005
Benzoxazole derivatives R 0230 The E and Z Isomers of 3-(Benzoxazol-2-yl)prop-2-enoic Acid-[synth... more Benzoxazole derivatives R 0230 The E and Z Isomers of 3-(Benzoxazol-2-yl)prop-2-enoic Acid-[synthesis and structural characterization of the E-and Z-isomers of the GABA analogue (I)].-(
ChemInform Abstract: Coumarin Assemblies in Solid State
ChemInform, 2008
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Magnetic Resonance in Chemistry, 1993
The Cd(I1) and Hg(I1) complexes of 4(1H)-quinazolinone-2,Sdihydro-2-thioxo (1) and the free ligan... more The Cd(I1) and Hg(I1) complexes of 4(1H)-quinazolinone-2,Sdihydro-2-thioxo (1) and the free ligand were studied by 1D and 2D multinuclear magnetic resonance in solution and I3C cross polarization magic angle spinning NMR in the solid state. Compound 1 adopts only one of five possible tautomeric structures in solution, namely the thiouracyl-like structure. It was found that the metal atom is linked to two molecules of deprotonated 1 by N-1 and coordinated by the sulphur atom. The compounds retain the same structure in the solid state and in dimethyl sulphoxide solution. KEY WORDS 'H, 13C, 15N and '13Cd NMR Two-dimensiona1 NMR CP/MAS NMR Hg and Cd compIexes 4(1H)-Quinazolinone-2.3-dihydro-2-thioxo
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Papers by Francisco Martínez-martínez