Mauricio F. Erben
National University of La Plata
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Featured researches published by Mauricio F. Erben.
Journal of Sulfur Chemistry | 2014
Aamer Saeed; Ulrich Flörke; Mauricio F. Erben
This review provides an overview of the chemistry, structure and potential applications of 1-(acyl/aroyl)-3-(mono-substituted) and 1-(acyl/aroyl)-3,3-(di-substituted) thioureas, with general formula R1C(O)N(1)HC(S)N(3)R2R3. In recent years, the title compounds have found extensive applications as ligands in coordination chemistry. The effect that nitrogen substituents exert on the intra- and intermolecular hydrogen-bonding interactions is discussed, including their role on the coordination properties displayed by these ligands. Novel applications of transition metal complexes bearing 1-(acyl/aroyl)-3-(mono- and di-substituted) thioureas are introduced. Biological aspects are also highlighted. As recently demonstrated, high-throughput screening assay and structure–activity analyses are feasible for this class of compounds. The chemical versatility of 1-(acyl)-3-(substituted) thiourea molecules and the derived metal complexes, together with the possibility of determining detailed structural properties, join biological applications in a promising interdisciplinary approach. The bibliography includes 382 references with emphasis on the literature appearing after 2007. GRAPHICAL ABSTRACT
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2013
Aamer Saeed; Mauricio F. Erben; Michael Bolte
1-(Adamantane-1-carbonyl)-3-(2,4-dichlorophenyl)thiourea (1) and 1-(adamantane-1-carbonyl)-3-(2-bromo-4,6-difluorophenyl)thiourea (2) were synthesized by the reaction of adamantane-1-carbonyl chloride with ammonium thiocyanate to afford the adamantane-1-carbonylisothiocyanate in situ followed by treatment with suitable halogenated anilines. The structures of the products were established by elemental analyses, Fourier transform infrared spectroscopy (FTIR), (1)H, (13)C nuclear magnetic resonance (NMR), mass spectroscopy and single crystal X-ray diffraction study. Bond lengths and angles show the usual values. All of three condensed cyclohexane rings of the adamantane residues adopt the usual chair conformation. The molecular conformation of 1 and 2 is stabilized by an intramolecular (NH⋯OC) hydrogen bond which forms a pseudo-six-membered ring. Structural features have been complemented with the joint analysis of the FTIR and FT-Raman spectra along with quantum chemical calculations at the B3LYP/6-311++G level.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2015
Aamer Saeed; Asma Khurshid; Michael Bolte; Adolfo C. Fantoni; Mauricio F. Erben
The vibrational analysis (FT-IR and FT-Raman) for the new 1-(2-chlorobenzoyl)thiourea species suggests that strong intramolecular interactions affect the conformational properties. The X-ray structure determination corroborates that an intramolecular N-H⋯OC hydrogen bond occurs between the carbonyl (-CO) and thioamide (-NH2) groups. Moreover, periodic system electron density and topological analysis have been applied to characterize the intermolecular interactions in the crystal. Extended N-H⋯SC hydrogen-bonding networks between both the thioamide (N-H) and carbamide (NH2) groups and the thiocarbonyl bond (CS) determine the crystal packing. The Natural Bond Orbital (NBO) population analysis demonstrates that strong hyperconjugative remote interactions are responsible for both, intra and intermolecular interactions. The Atom in Molecule (AIM) results also show that the N-H⋯Cl intramolecular hydrogen bond between the 2-Cl-phenyl ring and the amide group characterized in the free molecule changes to an N⋯Cl interaction as a consequence of crystal packing.
CrystEngComm | 2015
Aamer Saeed; Michael Bolte; Mauricio F. Erben; Hiram Pérez
The conformationally congested species 1-(adamantane-1-carbonyl)-3-(2,4,6-trimethylphenyl)thiourea has been prepared and fully characterized by elemental analyses, FTIR, 1H NMR, 13C NMR and mass spectrometry. Its crystal structure was determined by single-crystal X-ray diffraction. The dihedral angle between the plane of the 2,4,6-trimethylphenyl group and the plane of the thiourea fragment was optimized by theoretical calculations applying the B3LYP/6-311++G(d,p) level for the purpose of investigating the conformational effects on the stabilization of the crystal packing. A detailed analysis of the intermolecular interactions in a series of six closely related phenylthiourea species bearing the 1-(adamantane-1-carbonyl) group has been performed based on the Hirshfeld surfaces and their associated two-dimensional fingerprint plots. The relative contributions of the main intermolecular contacts as well as the enrichment ratios derived from the Hirshfeld surface analysis establish the 1-acyl thiourea synthon to be a widespread contributor.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2015
Aamer Saeed; Saba Ashraf; Jonathan M. White; Delia B. Soria; Carlos A. Franca; Mauricio F. Erben
Two novel 1-(1-naphthoyl)-3-(halo-phenyl) substituted thioureas, namely 1-(1-naphthoyl)-3-(2,4-di-fluoro-phenyl)-thiourea (1) and 1-(1-naphthoyl)-3-(3-chloro-4-fluoro-phenyl)-thiourea (2), were synthesized and fully characterized. The X-ray crystal and molecular structures have been determined resulting in a planar acylthiourea group, with the C=O and C=S adopting a pseudo-antiperiplanar conformation. An intramolecular N-H⋯O=C hydrogen bond occurs between the thioamide and carbonyl groups. The crystal packing of both compounds is characterized by extended intermolecular N-H⋯S=C and N-H⋯O=C hydrogen-bonding interactions involving the acylthiourea moiety. Compound 2 is further stabilized by π-stacking between adjacent naphthalene and phenyl rings. The thermal behavior, as well as the vibrational properties, studied by infrared and Raman spectroscopy data complemented by quantum chemical calculations at the B3PW91/6-311++G(d,p) support the formation of these intra- and intermolecular hydrogen bonds. Furthermore, the UV-Vis spectrum is interpreted in terms of TD-DFT quantum chemical calculations with the shapes of the simulated absorption spectra in good accordance with the experimental data.
New Journal of Chemistry | 2015
María Eliana Defonsi Lestard; Diego M. Gil; O. Estévez-Hernández; Mauricio F. Erben; Julio Duque
1-Benzyl-3-furoyl-1-phenylthiourea is a thiourea derivative synthesized and characterized by means of vibrational spectroscopy (IR and Raman) multinuclear NMR (1H and 13C) and elemental analysis. The geometrical parameters of this compound obtained from XRD studies were compared with the calculated values [B3LYP/6-311++G(d,p)] showing a good agreement. As determined by XRD analysis performed previously, the title compound exhibits the U-shape conformation with the CO and CS double bonds in anticlinal geometry. This conformational feature is mainly dictated by the substitution degree on the thiourea core and the ability to form an intramolecular N–H⋯OC hydrogen bond. The UV-visible absorption spectra of the compound in methanol solution were recorded and analyzed using time dependent density functional theory (TD-DFT). Molecular stability was investigated by applying the natural bond (NBO) analysis. Intermolecular interactions were evaluated by means of the AIM approach. The calculated HOMO and LUMO energies show that the charge transfer occurs in the molecule. The molecular electrostatic potential map was calculated by the DFT method. Non-linear optical (NLO) behavior of the title compound was investigated by determining the electric dipole moment, polarizability α, and hyperpolarizability β using B3LYP/6-311++G(d,p) approximation.
Acta Crystallographica Section B-structural Science | 2010
Khodayar Gholivand; Hossein Mostaanzadeh; Tomas Koval; Michal Dušek; Mauricio F. Erben; Helen Stoeckli-Evans; Carlos O. Della Védova
New phosphoramidates with the formula RC(O)N(H)P(O)X(2), R = 2-NO(2)-C(6)H(4), 3-NO(2)-C(6)H(4) and 4-NO(2)-C(6)H(4), X = N(CH(2)CH(3)) (1)-(3), NC(4)H(8) (4)-(6), and NC(4)H(8)O (7)-(9) were synthesized and characterized by (1)H, (13)C, (31)P NMR and IR spectroscopy, and elemental analysis. The reaction of (9) with hydrated lanthanide(III) nitrate leads to ten- or nine-coordinated complexes, (10)-(13). The crystal structure has been determined for (3), (5), (9), (10) and (13). In contrast to all of the previously reported similar phosphoramidate compounds, the -C(O)-N(H)-P(O) skeleton in the free ligand (9) shows a cisoid conformation, with the C=O and P=O double bonds adopting a nearly syn conformation. Quantum chemical calculations were applied for clarifying this exceptional conformational behavior. The monodentate neutral ligand (9) is coordinated to the metal ions via the phosphoryl O atom, adopting the usual anti conformation between the C=O and P=O groups.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2016
Aamer Saeed; M. Ifzan Arshad; Michael Bolte; Adolfo C. Fantoni; Zuly Yuliana Delgado Espinoza; Mauricio F. Erben
The 2-(phenyl-hydrazono)-succinic acid dimethyl ester compound was synthesized by reacting phenylhydrazine with dimethylacetylene dicarboxylate at room temperature and characterized by elemental analysis, infrared, Raman, (1)H and (13)C NMR spectroscopies and mass spectrometry. Its solid state structure was determined by X-ray diffraction methods. The X-ray structure determination corroborates that the molecule is present in the crystal as the hydrazone tautomer, probably favored by a strong intramolecular N-H···O=C hydrogen bond occurring between the carbonyl (-C=O) and the hydrazone -C=N-NH- groups. A substantial fragment of the molecular skeleton is planar due to an extended π-bonding delocalization. The topological analysis of the electron densities (Atom in Molecule, AIM) allows characterization of intramolecular N-H···O interaction, that can be classified as a resonant assisted hydrogen bond (RAHB). Moreover, the Natural Bond Orbital population analysis confirms that a strong hyperconjugative lpO1→σ*(N2-H) remote interaction between the C2=O1 and N2-H groups takes place. Periodic system electron density and topological analysis have been applied to characterize the intermolecular interactions in the crystal. Weak intermolecular interactions determine the crystal packing, and the prevalence of non-directional dispersive contributions are inferred on topological grounds. The IR spectrum of the crystalline compound was investigated by means of density functional theory calculations carried out with periodic boundary conditions on the crystal, showing excellent agreement between theory and the experiments. The vibrational assignment is complemented with the analysis of the Raman spectrum.
Journal of Organic Chemistry | 2012
Aamer Saeed; Mauricio F. Erben; Michael Bolte
A novel imide compound (C(16)H(10)ClNO(4)) was synthesized in a single step by the reaction of 2-furoic acid with 4-chloroaniline in a 2:1 molar ratio using carbonyldiimidazole (CDI) in dry THF. The structure was supported by spectroscopic and elemental analyses and the single-crystal X-ray diffraction data. Crystallographic studies revealed that the compound crystallized in a monoclinic system with space group P2(1)/c and unit cell dimensions a = 12.2575(5) Å, b = 7.7596(2) Å, c = 15.0234(7) Å, α = γ = 90°, β = 92.771(4)°, V = 1427.25(10) Å(3), Z = 4. The imide bond is twisted, and the O═C-N-C(O) units deviate significantly from planarity with dihedral angles around the imide group reaching ca. -150.3° (C1-N1-C2-O21 = -148.8° and C2-N1-C1-O11 = -151.9°). The nonplanarity of the imide moiety and the related conformational properties are discussed in a combined approach that includes the analysis of the vibrational spectra together with theoretical calculation methods, especially in terms of natural bond orbital (NBO) calculations.
Journal of Physical Chemistry A | 2009
Emiliano Cortés; Carlos O. Della Védova; Mariana Geronés; Rosana M. Romano; Mauricio F. Erben
We have investigated the dissociative photoionization of shallow-core excited CCl3SCl by using multicoincidence time-of-flight mass spectrometry and synchrotron radiation in the S 2p and Cl 2p edges. The relative abundances of the ionic fragments and their kinetic energy release values were obtained from both PEPICO (photoelectron photoion coincidence) and PEPIPICO (photoelectron photoion photoion coincidence) spectra. The dynamic of the ionic fragmentation of S and Cl 2p excited CCl3SCl has been studied and compared with those of CCl4. Features determined in the present study seem to be relevant aspects for explaining the dissociation of highly chlorinated species under the action of VUV irradiation. The fragmentation pattern shows that chlorine ion (Cl+) is prominently formed upon both S and Cl 2p excitations.