Synthesis of New Ruthenium Complexes and Their Exploratory Study as Polymer Hybrid Composites in Organic Electronics.

Polymeric hybrid films, for their application in organic electronics, were produced from new ruthenium indanones in poly(methyl methacrylate) (PMMA) by the drop-casting procedure. Initially, the synthesis and structural characterization of the ruthenium complexes were performed, and subsequently, their properties as a potential semiconductor material were explored. Hence hybrid films in ruthenium complexes were deposited using PMMA as a polymeric matrix. The hybrid films were characterized by infrared spectrophotometry and atomic force microscopy. The obtained results confirmed that the presence of the ruthenium complexes enhanced the mechanical properties in addition to increasing the transmittance, favoring the determination of their optical parameters. Both hybrid films exhibited a maximum stress around 10.5 MPa and a Knoop hardness between 2.1 and 18.4. Regarding the optical parameters, the maximum transparency was obtained at wavelengths greater than 590 nm, the optical band gap was in the range of 1.73-2.24 eV, while the Tauc band gap was in the range of 1.68-2.17 eV, and the Urbach energy was between 0.29 and 0.50 eV. Consequently, the above comments are indicative of an adequate semiconductor behavior; hence, the target polymeric hybrid films must be welcomed as convenient candidates as active layers or transparent electrodes in organic electronics.

Synthesis of Functionalized Tetrasubstituted Allenes by the Addition of Bis(trimethylsilyl)ketene Acetals to Ynones Catalyzed by Gold(I).

We have developed a straightforward and rapid methodology for the synthesis of tetrasubstituted allenes bearing carboxylic acids in the 1,3-position through the gold(I)-catalyzed nucleophilic addition of bis(trimethylsilyl)ketene acetals to ynones. The reaction was evaluated with several substrates, and 21 allenes were obtained in moderate to good yields. Using DFT calculations, we studied the mechanism of the reaction, which suggested a nucleophilic 1,4-addition pathway. The potential of allenes to act as a source of highly functionalized lactones was also explored.

Structural determination, characterization and computational studies of doped semiconductors base silicon phthalocyanine dihydroxide and dienynoic acids.

The chemical doping of silicon phthalocyanine dihydroxide (SiPc(OH)2), with (2E, 4Z)-5, 7-diphenylhepta-2, 4-dien-6-ynoic acids (DAc) with electron-withdrawing (BrDAc) and electron-donating (MeODAc) substituents is the main purpose of this work. Theoretical calculations were carried out on Gaussian16 software, with geometrical optimization of all involved species, and obtention of the highest occupied molecule orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and the respective energy gaps. The theoretical calculations show two hydrogen bridge formations: the first one as a peripheral interaction between the terminal oxygen atoms from the acid unit and hydrogen atoms from the phthalocyanine aromatic rings. The second one as the interaction at the nitrogen atoms of the phthalocyanine, which are compelled to form a new flat plane far from the original flat phthalocyanine deck. These organic semiconductors were deposited as thin films and characterized by IR spectroscopy, atomic force microscopy (AFM), and the optical parameters were gathered from UV-Vis studies. The indirect and direct optical band gap, the onset gap and the Urbach energy were obtained. In order to compare the effect of the acids as dopants of the silicon phthalocyanine, the SiPc(OH)2-DAc films were electrically characterized. The SiPc(OH)2-DAc films exhibit an ambipolar electrical behavior, which is influenced by the incidence of different lighting conditions at voltages above 0.3V. The glass/ITO/SiPc(OH)2-MeODAc/Ag reaches a maximum current of 5.68 × 10-5 A for natural light condition, while the glass/ITO/SiPc(OH)2-BrDAc/Ag, reaches a maximum current of 9.21 × 10-9 A for white illumination condition.

Design of Promising Uranyl(VI) Complexes Thin Films with Potential Applications in Molecular Electronics.

In this work, it is proposed the development of organic semiconductors (OS) based on uranyl(VI) complexes. The above by means of the synthesis and the characterization of the complexes by Infrared spectroscopy, Nuclear magnetic resonance spectroscopy, mass spectrometry, and X-ray diffraction. Films of these complexes were deposited and subsequently, topographic and structural characterization was carried out by Scanning Electron Microscopy, X-ray diffraction, and Atomic Force Microscopy. Additionally, the nanomechanical evaluation was performed to know the stiffness of uranyl films using their modulus of elasticity. Also, the optical characterization took place in the devices and their bandgap value ranges between 2.40 and 2.93 eV being the minor for the film of the uranyl complex with the N on pyridine in position 4 (2 c). Finally, the electrical behavior of the uranyl(VI) films was evaluated, and important differences were obtained: the uranyl complex with the N on pyridine in position 2 (2 a) film is not influenced by changes in lighting and its current density is in the order of 10-3 A/cm2. The film with uranyl complex with the N on pyridine in position 3 (2 b) and 2 c presents a greater current flow under lighting conditions and two orders of magnitude larger than in film 2 a. In these films 2 b and 2 c, ohmic behavior occurs at low voltages, while at high voltages the charge transport changes to space-charge limited current behavior.

Aislamiento y elucidación estructural por resonancia magnética nuclear (RMN 1H, RMN 13C, DEPT135, COSY y HSQC) del compuesto (E)-1,3,5-trimetoxi-2-(prop-1-enil) benceno extraído de hojas de Piper patulum / Isolation and structural elucidation by nuclear magnetic resonance (1H NMR, 13C NMR, DEPT135, COSY and HSQC) of compound (E) -1,3,5-trimethoxy-2- (prop-1-enyl) benzene extracted from Piper patulum

Guatemala es un país de gran diversidad biológica, la que ha permitido a diferentes investigadores de productos naturales, obtener resultados de interés y relevancia científica, principalmente sobre propiedades farmacológicas, sin embargo, hasta el momento se desconoce la estructura molecular, conformaciones y configuraciones exactas de muchos de los metabolitos secundarios responsables de dichas propiedades. Por lo tanto, en esta investigación se planteó como objetivo aislar y elucidar la estructura de un fenilpropanoide obtenido en las hojas de Piper patulum. El aislamiento se realizó por extracciones líquido-líquido y técnicas cromatográficas (cromatografía en columna -CC-), obteniendo .092 g del compuesto de interés. La elucidación se realizó por espectroscopía de masas, espectroscopia infrarroja -IR- y experimentos de resonancia magnética nuclear -RMN-, dando como resultado la estructura correspondiente a (E)-1,3,5-trimetoxi-2-(prop-1- enil) benceno. Posteriormente el fenilpropanoide presentó actividad antioxidante mediante la prueba cualitativa con 2,2- difenil-1-picrilhidrazilo -DPPH-.

Guatemala is a country of great biological diversity, which has led natural product researchers to obtain results of great interest and scientific relevance, mainly in pharmacological properties; However, the molecular structure, conformations, and configurations of many secondary metabolites responsible for these properties are unknown. In this research, the objective was to isolate and elucidate the structure of a phenylpropanoid obtained from in the leaves of Piper patulum. The isolation was carried out by liquid-liquid extractions and chromatographic techniques (Column Chromatography -CC-), obtaining .092 g. The elucidation was performed by mass spectroscopy, infrared spectroscopy -IR- and nuclear magnetic resonance experiments-NMR-, the data obtained indicates the corresponding (E) -1,3,5-trimethoxy-2- (prop-1-enyl) benzene. Subsequently, the phenylpropanoid presented antioxidant activity through the qualitative test with 2,2-diphenyl-1-picrylhydrazyl-DPPH