Two new beta-aminoenones, NH-alkyl (2Z)-3-butylamino-4,4,4-trifluoro-1-(2-hydroxy-5-nitrophenyl)but-2-en-1-one (1) and its NH2 amino counterpart (2), were synthesized and characterized using experimental and theoretical methods. These closely related compounds differ only in their amino substitution. Spectroscopic data (IR, UV-vis and NMR spectra) reveal characteristic bands and shifts associated with push-pull electronic distribution and support the planar conformation and tautomeric stability of the enaminone core. X-ray diffraction revealed nearly planar conformations stabilized by intramolecular O-H & ctdot;O and N-H & ctdot;O hydrogen bonds forming two six-membered pseudo-rings, while compound 2 also exhibits polymeric contacts associated with its primary amine functionality. Hirshfeld surface and interaction energy analyses indicated that electrostatic and dispersive forces dominate crystal packing, with enhanced van der Waals contributions in 1 due to the butyl chain. QTAIM and NBO analyses confirmed the resonance-assisted hydrogen bonding (RAHB) character of these interactions and elucidated key charge transfer pathways. The antioxidant activity evaluated using the DPPH assay complements the structural results, suggesting that the radical scavenging potential depends on the amino substituent. These results highlight the importance of push-pull effects in modulating molecular reactivity, supramolecular architecture, and potential bioactivity.

Penaeus sp. shells (shrimp) were used to extract chitosan using acid and basic treatments, which were characterized by IR spectroscopy, Raman spectroscopy, potentiometric titration, and elemental analysis. The degrees of deacetylation were determined to be 71.8%, 75.6%, 53.4%, and 68.6%, respectively. Likewise, viscosimetry measurements were carried out, determining an average molecular weight of chitosan 1 of 1521467.919 (g/mol). The obtained chitosan was used as a substrate in condensation reactions with 10 para-substituted benzaldehydes. The products obtained were characterized by IR, Raman, and 1H-NMR spectroscopy, AE (Elemental Analysis), TGA (Thermogravimetric Analysis), and DSC (Differential Scanning Calorimetry). For the obtained polymers, biological assays of cytotoxicity using RAW macrophage cells and leishmanicidal activity on promastigotes of Leishmania mexicana were performed. The results show that the synthesized products do not present in vitro cytotoxicity, and that 1 (Chitosan) and 3i (Schiff Base) present leishmanicidal activity. Selected derivatives were incorporated into polyvinyl alcohol-based films and evaluated for surface topography and gas permeability. AFM revealed nanometric roughness patterns, while gas exchange studies demonstrated selective CO2/O2 permeability, supporting passive modified atmosphere formation in packaged carrots. Mechanical characterization revealed that the incorporation of Schiff base derivatives significantly influences tensile strength and flexibility, with certain films exhibiting enhanced elongation and mechanical performance compared to pure PVA, highlighting their potential for packaging applications. These findings confirm that chemical functionalization enhances the versatility of chitosan, allowing the design of tailored biopolymers. The synthesized derivatives show promising characteristics for the development of biodegradable films with potential applications in food packaging and antiparasitic material development.

Chromone derivatives are privileged scaffolds in organic and medicinal chemistry. Their functionalization with organosulfur groups opens opportunities to explore new structural and electronic properties. Two novel diethyldithiocarbamyl chromones were synthesized under mild conditions and characterized by IR, Raman, UV-vis, NMR spectroscopy, and single-crystal X-ray diffraction, and complemented with density functional theory (DFT) calculations. Spectroscopic analyses confirmed the characteristic vibrational modes of the chromone and dithiocarbamate moieties, in agreement with the most stable conformers. The UV-vis spectra showed intense absorptions in the 200-310 nm region, dominated by pi -> pi* and n -> pi* transitions. Notably, the LUMO+2 orbital was localized on the (sic) N-C = S-2 group in both compounds, highlighting a common electronic feature despite structural differences. Crystallographic studies demonstrated the planarity of the chromone core and resonance stabilization of the dithiocarbamate fragment. Hirshfeld surface and lattice energy analyses revealed that dispersive interactions govern crystal packing, complemented by occasional C-H & ctdot;O hydrogen bonds. This combined experimental and theoretical approach provides a clear picture of the structural and electronic behavior of these new derivatives. The findings emphasize how dithiocarbamate substitution shapes orbital contributions and electronic absorption, offering valuable insights for future applications in supramolecular design, functional materials, and medicinal chemistry.

(Z)-3-butylamino-4,4,4-trifluoro-1-(2-hydroxyphenyl)but-2-en-1-one (1), a new β-aminoenone, has been investigated in terms of its intra- and intermolecular interactions. Vibrational, electronic and nuclear magnetic resonance spectroscopies were used for the characterization, while X-ray diffraction methods afforded the determination of the crystal structure. The compound is arranged in the crystal lattice as centre-symmetric H-bonded dimeric aggregates (C2/c monoclinic space group). Both experimental (infrared, Raman, ultraviolet-visible transitions and X-ray diffraction data) and theoretical (Quantum Theory of Atoms in Molecules and Natural Bond Orbital approaches, calculated spectra and conformational analysis) methods were used to obtain a deep insight into the intra- and intermolecular contacts. The interactions were quali- and quantitatively analysed and the data compared with closely related compounds. In vitro experiments were carried out in this work to evaluate the antibacterial activity of 1 against Gram-positive and Gram-negative bacteria, particularly Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (6538). Compound 1 demonstrated a discernible suppression of biofilm formation and quorum sensing of both bacterial strains, indicating that it may be developed as an antibacterial candidate to reduce bacterial resistance and persistence on surfaces across a range of industries.

Two new heterocycles, containing the vicinal triazole pharmacophore, were synthesized and studied exhaustively by spectroscopic methods, computational calculations and X-ray diffraction. The compounds (2-hydroxy-3,5dimethylphenyl)[5-(trifluoromethyl)-2H-1,2,3-triazol-4-yl]methanone (a) and (5-chloro-2-hydroxy-3-methylphenyl)[5-(trifluoromethyl)-2H-1,2,3-triazol-4-yl]methanone (b) are interesting because their structure allows the nitrogen atoms of the pharmacophore to remain free, increasing its interaction potential. Furthermore, 4,5-disubstituted vicinal triazoles have received less attention since they cannot be produced using click chemistry. The crystal structure of both compounds was determined by X-ray diffraction methods. Quantum chemical calculations were implemented to support the analysis of vibrational and electronic spectroscopic properties by Density Functional Theory (DFT). The study of the intermolecular interactions was undertaken through Molecular Electrostatic Potential (MEP) maps, Hirshfeld surfaces (HS), Natural Bond Orbitals (NBO) and Quantum Theory of Atoms in Molecules (QTAIM). Strong (O-H center dot center dot center dot O and N-H center dot center dot center dot O) and weak (C-H center dot center dot center dot F and N-H center dot center dot center dot F) hydrogen bonding interactions together with F center dot center dot center dot F, O center dot center dot center dot C and it center dot center dot center dot it stacking contacts are the basis on which the sheets and layers of the studied compounds are formed. The dispersive energy component predominates in the stabilization of the layers. The intramolecular hydrogen bonding is much stronger in compound a, since the interaction is influenced by the intramolecular N-H center dot center dot center dot O contacts. The second-order stabilization energy (E(2), NBO) and the interaction energy (Eint, QTAIM) associated with this interaction support the analysis.

The elusive S-(trifluoromethyl)O-(methyl) thioperoxide, CF3SOCH3, and its methyl deuterated isotopologue, CF3SOCD3 were prepared for the first time via the reaction between CF3SCl and CH3OH or CD3OH, respectively. The novel compounds were thoroughly characterized using vibrational (FTIR and FT-Raman) and multinuclear NMR (1H, 19F and 13C) spectroscopies. The vibrational properties of this thioperoxide were assigned through detailed analysis of its infrared (gas-phase and matrix-isolated) and Raman spectra supported by quantum chemical calculations. CF3SOCH3 was isolated in the Ar matrix at cryogenic temperatures and exposed to broadband UV irradiation in the 225-800 nm region. The photochemical stability of the compound has thus been determined in the UV-vis range.

Two new 1,3-dicarbonyl compounds bearing an o-hydroxyphenyl moiety (for short, I and II) were synthesized and subjected to structural, experimental and theoretical studies. Vibrational spectroscopy (IR and Raman) and X-ray diffraction were used for solid phase studies, while NMR and electron spectroscopy allowed analysis in solution. The crystal structures of I and II, determined by X-ray diffraction methods, are closely related to each other (rms deviation of homologous atoms from their best fit is 0.147 & Aring;). The observed planarity of beta-hydroxyphenylcarbonyl enols fragment in the compounds is enforced by both extended pi-bonding and intramolecular OH & ctdot;O bonds. Molecules in I are arranged in the lattice as center-symmetric dimers held by relatively weak intermolecular OH & ctdot;O bonds. Hirshfeld surface (HS) analysis, atoms in molecules (QTAIM), and natural bonding orbitals (NBO) approaches were employed to study theoretically selected dimers constructed from X-ray data. The results were combined with experimental ones to obtain deep insight into the strength and type of intermolecular interactions. A chalcogen bond interaction was detected in I. Although the O & ctdot;O interaction is unusual, it participates in the attractive forces that stabilize the crystal lattice. The title compounds are present in the solid state only as the keto-enol tautomer, while in solution the diketo tautomer is also detected at concentrations of 5%. In vitro studies showed that I have better antimicrobial properties than II, mainly against the S. aureus strain. Intra- and intermolecular contacts in 1,3-dicarbonyl compounds are dominated by O-H & ctdot;O bonds. When molecules face each other, the unusual intermolecular O & ctdot;O bonds can reinforce adjacent O-H & ctdot;O bonds and form centrosymmetric dimers.

The solid-state molecular structures of N-(butylcarbamothioyl)-4-methoxybenzamide (I) and N-(butylcarbamoyl)-4-methoxybenzamide (II) were used as examples for structural analyses of carbonylthioureides and carbonylureides. Both compounds crystallize in the monoclinic P21/c space group and form nearly identical hydrogen-bonded dimeric aggregates. A thorough examination of intermolecular interactions using X-ray diffraction data, Hirshfeld surface analysis, molecular electrostatic potential maps, NBO and QTAIM approaches, and spectroscopic techniques reveals that the larger size of the sulfur atom has a significant impact on the strength and nature of the interactions within the crystal lattice. Furthermore, the isosteric exchange was evaluated by testing the activity of both compounds as antibiofilm and anti-quorum sensing agents. Structural study of carbonyl(thio)ureides and a comprehensive analysis on the intermolecular interactions that stabilize the crystal packing. Sulfur, rather than oxygen, promotes Quorum Sensing inhibition by reducing cell viability in a developed biofilm.

All peroxides RO-OR' and disulfanes RS-SR', whose gas phase structures are known, possess gauche structures and most of them possess dihedral angles between 80 degrees and 120 degrees. Thioperoxides of the type RS-OR' are much less stable than peroxides and disulfanes and very little is known about their structural properties. Sulfenic acid, HSOH, dimethoxysulfane, CH3OSOCH3 and dimethoxydisulfane, CH3OSSOCH3, possess gauche structures with dihedral angles between 75 degrees and 90 degrees. A combination of vibrational spectroscopy, gas electron diffraction and quantum chemical calculations results for trifluoromethanesulfenyl acetate, CF3S-OC(O)CH3, and for trifluoromethanesulfenyl trifluoroacetate, CF3S-OC(O)CF3, in a mixture of two conformers with the prevailing component possessing gauche structure. The minor form (18(5)% and 11(5)%, respectively) possesses an unexpected trans structure around the S-O bond. The C=O bond of the acetyl group is oriented syn with respect to the S-0 bond in both conformers. A similar experimental and theoretical study of S-(fluoroformyl)O(trifluoroacetyl)thioperoxide, FC(O)S-OC(O)CF3, results also in a mixture of two conformers. In this thioperoxide, however, both conformers possess gauche structure around the S-0 bond and differ only by the orientation of the FC(O) group (C=O bond syn or anti with respect to the S-O bond).

Trifluoroethyl methansulfonate (methylsulfonyl), TFMSMS is a new compound derived from Clomesone, which was obtained in solid state. As no experimental geometric parameters were available, a conformational exploration was carried out (using the concept of "conformational transferability"), resulting a single stable conformation at room temperature. Infrared, Raman, and liquid NMR spectra were measured. The contributions of the donor -> acceptor interaction energies were also analyzed by Natural Bond Orbitals (NBO) approximations and topological properties (AIM). These results evidenced that electron delocalization and especially LP O -> sigma*O(3)-C(3) interaction play an important role in the reactivity-structure connection of oxoesters and thioesters. TFMSMS could partially inhibit growth and biofilm formation on Pseudomonas aeruginosa and Staphylococcus aureus strains. Moreover, this is the first study demonstrating the methansulfonate complex interference with the Quorum sensing system in Gram-negative bacteria.

The structure of two perhalomethylated chromones, 2-chlorodifluoromethylchromone (a) and its 6-nitro substituted derivative (b), are investigated. The supramolecular assembly is governed by the hydrogen bond interaction (C-H center dot center dot center dot O) between the olefinic proton (OC-C(=CH) and the carbonyl oxygen atom (>C=O) giving rise to center-symmetric R22(8)$R_2<^>2( 8 )$ graph-set motifs. The H center dot center dot center dot O interatomic distance is shorter in (b) suggesting a stronger hydrogen bonding for this derivative. Quantum Theory of Atoms in Molecules (QTAIM) and natural bond orbital (NBO) calculated energies and the higher polarity computed for (b) agree with this experimental finding. The Molecular Electrostatic Potential (MEP) graph shows a distinctive C center dot center dot center dot Cl contact, found only for (b), involving a more electrophilic methine carbon atom.

Se estudió por métodos teóricos la naturaleza de las principales interacciones intermoleculares, a partir del análisis de archivos de información cristalográfica (CIF) de moléculas pseudohalogenadas CCl2FSCN*, CCl3SCN*, ClC(O)SCN*, FC(O)NCS*, FC(O)SCN*. Se estudió por el método de Hirshfeld, la contribución de las principales interacciones intermoleculares (gráficos 2D huellas dactilares) y las energías de interacción. Por otra parte, se realizó el análisis AIM, NCI, Laplaciano de la densidad electrónica y mapas de potencial electrostático, analizando varios parámetros fisicoquímicos como la lagraniana G(r), energía potencial virial V(r), Laplaciana, Hamiltoniano de la energía cinética H(r) y el operador , que permitieron clarificar el carácter y tipo de interacción intermolecular, complementando con el análisis NBO. Para las moléculas CCl2FC(O)NCS, CCl2FC(O)SCN, CCl3C(O)NCS, CCl3C(O)SCN, ClC(O)NCS, ClSCN y FSCN no se disponía de información cristalográfica (CIF), por lo tanto, se realizó una evaluación mediante análisis AIM, NCI, Laplaciano y mapas de potencial electrostático. Se utilizó software como Gaussian16W, MultiWfn, Crystal Explorer, Mercury, VMD y WinGx. Se evidenció interacciones N…S (calcógena), Cl…F (halógena) y N…Cl (halógeno) tipo agujero sigma presentes en las moléculas de tipo XC(O)SCN y XSCN (CCl2FSCN*, CCl3SCN*, ClC(O)SCN*, FC(O)NCS* y FC(O)SCN*) estudiadas desde los archivos CIF. Por otra parte, en el análisis de los mapas de potencial electrostático y el comportamiento del Laplaciano de densidad electrónica en los átomos, sin estructura cristalina (CIF), ClSCN evidencia disminución de la densidad electrónica en el átomo de cloro, por lo tanto, muestra potencial para formar interacciones N…Cl (halógeno), mientras que FSCN, CCl2FCOSCN y CCl3COSCN sugieren la probabilidad de interacciones N…S (calcógenas).

A series of 2-(haloalkyl)-3-azidomethyl and 6-azido chromones has been synthetized, characterized and studied by theoretical (DFT calculations) and spectroscopic methods (UV-Vis, NMR). The crystal structure of 3-azidomethyl-2-difluoromethyl chromone, determined by X-ray diffraction methods, shows a planar framework due to extended π-bond delocalization. Its molecular packing is stabilized by F···H, N···H and O···H hydrogen bonds, π···π stacking and C–O···π intermolecular interactions. Moreover, AIM, NCI and Hirshfeld analysis evidenced that azido moiety has a significant role in the stabilization of crystal packing through weak intermolecular interactions, where analysis of electronic density suggested closed-shell (CS) interatomic interactions.

A new perfluoromethylated vinylogous amide, (Z)-4,4,4-trifluoro-1-(2-hydroxyphenyl)-3-(2-methoxyethylamino)-2-buten-1-one, is chosen as an example to investigate the bonding interactions in solid state. The Z, s-cis form is the dominant conformation in both solution and solid state. Intramolecular hydrogen bonding determines this conformational preference in a nonpolar solvent (NMR spectra). Carbonyl and phenol groups are sensitive to the intra- and intermolecular contacts (vibrational spectra). The supramolecular assembly (X-ray diffraction) is governed by NHMIDLINE HORIZONTAL ELLIPSISO and OHMIDLINE HORIZONTAL ELLIPSISO strong intermolecular hydrogen bonds giving rise to center-symmetric R22(16) and R22(12) graph-set motifs. The pi-stacking, FMIDLINE HORIZONTAL ELLIPSISH and FMIDLINE HORIZONTAL ELLIPSISF interactions are also discussed (Hirshfeld analysis).

A set of seven new chromones with 2-haloalkyl (-CF2H, -CCl2H, -CF2CF3) and 3-bromo and bromomethyl substituents were synthesized. The novel compounds were studied by DFT calculations and characterized by vibrational spectroscopy (IR and Raman) in solid state, and NMR (H-1, C-13 and F-19) and UV-vis spectroscopy in solution. The crystal structure of 3-dibromomethyl-2-difluommethyl chromone was determined by X-ray diffraction. Due to extended pi-bond delocalization, the organic framework is planar and lies on a crystallographic m-mirror plane. The intermolecular non-covalent interactions of 3-dibromomethyl-2-difluommethyl chmmone, as pi center dot center dot center dot pi stacking arrangements, F center dot center dot center dot H hydrogen bonds and O center dot center dot center dot Br contacts were evaluated by Hirshfeld surfaces analysis. These intermolecular contacts, which affect the absorption bands location of the involved groups, were also detected in the vibrational spectra.

A new trifluoromethyl-1,5-benzodiazepine (BDZP) was synthesized from 2-trifluoromethyl chromone and o-phenylendiamine in ethanol. The X-ray crystal structure determination of BDZP shows that the compound exists in the solid as Enol-imine and Keto-enamine tautomeric, with prevalence of the former tautomer. The crystal packing of BDZP is stabilized by C-H center dot center dot center dot F, C-H center dot center dot center dot O, C-H center dot center dot center dot pi, pi center dot center dot center dot pi stacking, lone pair (F) center dot center dot center dot pi and F center dot center dot center dot F interactions. These contacts were evaluated in detail by Hirshfeld surface analysis and DFT calculations. Energy framework calculations afforded to analyze and visualize the topology of the intermolecular interactions responsible for the crystal packing, showing that dispersion interaction prevails over the electrostatic energy in all structural motifs of BDZP.

Clenbuterol is a steroid-type drug used in respiratory treatments in both humans and animals. However, it has a secondary effect related to the hypertrophy process in muscle and fat reduction. The illegal or bad use of clenbuterol has been reported in several countries, but there is scarce information in South America, where the production and consumption of meat are considerable. In this sense, the present study aimed at evaluating the occurrence of clenbuterol in bovine muscle and liver samples from a high cattle production area of Ecuador in 2015 and 2018. For this purpose, 57-58 samples were evaluated in 2015 and 20 samples in 2018 using the Enzyme-Linked Inmuno Sorbent Assay and ultrahigh-performance liquid chromatography-tandem mass spectrometry. The results showed complained results for clenbuterol in meat samples from both years and 23% (2015) and 85% (2018) of the samples of meat complied the maximum residue level defined by CODEX.

Comprehensive theoretical, structural and spectroscopic investigations on new substituted 1,2,3-triazoles in the solid state.

Bis - (methylsulfonylmethyl) sulfone, BMSMS, was synthesized and characterized through vibrational (IR, Raman) spectroscopy. The crystal structure of BMSMS, determined by X-ray diffraction methods, together with Hirshfeld surfaces analysis were used to evaluate intermolecular interactions. BMSMS can be considered as one-turn helix of about 7.13 Å, further stabilized by weak intra-molecular CH•••O bonds. The experimental results were supplemented by quantum chemical calculations. It was also analyzed the hyperconjugative effects of oxygen atoms lone pairs (LP) on the vibrational behavior of the SO2 group. Besides, biofilm formation and QS activity were evaluated on this new bis- (methylsulfonylmethyl) sulfone.