Síntesis asimétrica de cianoderivados bencílicos y terciarios y cuaternarios

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Orgánica. Fecha de lectura 11-05-200

Synthesis and Complexation of Polytopic Adamantane-Based Probes

The 9th International Electronic Conference on Synthetic Organic Chemistry session Supramolecular ChemistryThe authors thank the Ministerio de Ciencia y Tecnología (Project MAT2001-2911) and Xunta de Galicia (PGIDIT02PXIC26202PN) for financial support. V. H. Soto thanks AECI (Beca Mutis)/University of Costa Rica for a research scholarshi

Paramagnetic epoxy resin

This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0) and hemin (a protoporphyrin IX containing the Fe(III) ion, and an additional chloride ligand) have been chosen. The new material has been characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR), Transmission Electron Microscopy (TEM), and magnetic susceptibility measurements). Fe(III) remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III) can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.The authors thank the Ministerio de Ciencia y Tecnología, Spain, Project MAT2010-61721 for financial support. ECV also thanks Dr. Senén Paz and GAIRESA for a scholarshipS

Highly Hydrophilic and Lipophilic Derivatives of Bile Salts

Lipophilicity of 15 derivatives of sodium cholate, defined by the octan-1-ol/water partition coefficient (log P), has been theoretically determined by the Virtual log P method. These derivatives bear highly hydrophobic or highly hydrophilic substituents at the C3 position of the steroid nucleus, being linked to it through an amide bond. The difference between the maximum value of log P and the minimum one is enlarged to 3.5. The partition coefficient and the critical micelle concentration (cmc) are tightly related by a double-logarithm relationship (VirtuallogP=−(1.00±0.09)log(cmcmM)+(2.79±0.09)), meaning that the Gibbs free energies for the transfer of a bile anion from water to either a micelle or to octan-1-ol differ by a constant. The equation also means that cmc can be used as a measurement of lipophilicity. The demicellization of the aggregates formed by three derivatives of sodium cholate bearing bulky hydrophobic substituents has been studied by surface tension and isothermal titration calorimetry. Aggregation numbers, enthalpies, free energies, entropies, and heat capacities, ΔCP,demic, were obtained. ΔCP,demic, being positive, means that the interior of the aggregates is hydrophobicThis work was funded by the Ministerio de Ciencia y Tecnología, Spain (Project MAT2017-86109P)S

Evolutionary-based prediction interval estimation by blending solar radiation forecasting models using meteorological weather types

Recent research has shown that the integration or blending of different forecasting models is able to improve the predictions of solar radiation. However, most works perform model blending to improve point forecasts, but the integration of forecasting models to improve probabilistic forecasting has not received much attention. In this work the estimation of prediction intervals for the integration of four Global Horizontal Irradiance (GHI) forecasting models (Smart Persistence, WRF-solar, CIADcast, and Satellite) is addressed. Several short-term forecasting horizons, up to one hour ahead, have been analyzed. Within this context, one of the aims of the article is to study whether knowledge about the synoptic weather conditions, which are related to the stability of weather, might help to reduce the uncertainty represented by prediction intervals. In order to deal with this issue, information about which weather type is present at the time of prediction, has been used by the blending model. Four weather types have been considered. A multi-objective variant of the Lower Upper Bound Estimation approach has been used in this work for prediction interval estimation and compared with two baseline methods: Quantile Regression (QR) and Gradient Boosting (GBR). An exhaustive experimental validation has been carried out, using data registered at Seville in the Southern Iberian Peninsula. Results show that, in general, using weather type information reduces uncertainty of prediction intervals, according to all performance metrics used. More specifically, and with respect to one of the metrics (the ratio between interval coverage and width), for high-coverage (0.90, 0.95) prediction intervals, using weather type enhances the ratio of the multi-objective approach by 2%¿. Also, comparing the multi-objective approach versus the two baselines for high-coverage intervals, the improvement is 11%¿% over QR and 10%¿% over GBR. Improvements for low-coverage intervals (0.85) are smaller.The authors are supported by projects funded by Agencia Estatal de Investigación, Spain (PID2019-107455RB-C21 and PID2019-107455RB-C22/AEI/10.13039/501100011033). Also supported by Spanish Ministry of Economy and Competitiveness, project ENE2014-56126-C2-1-R and ENE2014-56126-C2-2-R (http://prosol.uc3m.es). The University of Jaén team is also supported by FEDER, Spain funds and by the Junta de Andalucía, Spain (Research group TEP-220

Study of the crosslinking reaction between Bisphenol A diglycidyl ether (BADGE) and a Zinc Porphyrin by Fourier transform infrared spectroscopy

The 19th International Electronic Conference on Synthetic Organic Chemistry session Polymer and Supramolecular ChemistryThe curing reaction of a system consisting of a diglycidyl ether of bisphenol-A (n= 0) and ZnTPyP (Zinc 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphyrin) was studied by Fourier Transform infrared spectroscopy (FTIR). A semi-empirical quantum chemistry program (MOPAC) was used to corroborate the experimental data. The tertiary amine ZnTPyP not only initiates the reaction but also reacts with the resin forming pyridone. This study demonstrates that macrocycles can be used as cross-linking agents for curing epoxy resins and that when metallomacrocycles are used, metal ions can be introduced into the network structur

Synthesis and characterization of new tail-to-tail dimers of bile acids with different spacers

The 13th International Electronic Conference on Synthetic Organic Chemistry session Polymer and Supramolecular ChemistryNew dimeric steroid-based surfactants derived from 3α,7α,12α-trihydroxy-5β- cholan-24-amine (steroid residue) and isophthalic acid, 5,5'-biisobenzofuran-1,1',3,3'- carboxylic acid and succinic acid (spacers) were synthesized and structurally characterized by NMR techniques. The first spacer was also employed to synthesize the dimer corresponding to the 3α,12α-dihydroxy-5β-cholan-24-amine residue. In all cases the steroid residues are tail-to-tail linked through amide bonds with the spacersAuthors thank the Ministerio de Ciencia y Tecnología (Project MAT2004-04606) and the Xunta de Galicia (PGIDIT05PXIC26201PN) for financial suppor

Theoretical calculations on conformations of bile-acid based dimers. Interactions with ibuprofen

The 13th International Electronic Conference on Synthetic Organic Chemistry session Polymer and Supramolecular ChemistryAn AM1 semiempirical method (Gaussian 03) was used to perform molecular structure optimizations in gas phase of two tail-to-tail bile acid-based dimers by an isophthalic acid bridge. The method was also used to study the interactions with the potential guest ibuprofen with the idea of applicative resultsAuthors thank the Ministerio de Ciencia y Tecnología (Project MAT2004-04606) and the Xunta de Galicia (PGIDIT05PXIC26201PN) for financial suppor

Synthesis and Characterization of a New Gemini Surfactant Derived from 3a,7a,12a-trihydroxy-5ß-cholan-24-amine (Steroid Residue) and Ethylenediamintetraacetic Acid (Spacer)

The 12th International Electronic Conference on Synthetic Organic Chemistry session Supramolecular ChemistryA new gemini steroid surfactant derived from 3a,7a,12a-trihydroxy-5ß-cholan-24-amine (steroid residue) and ethylenediamintetraacetic acid (spacer) was synthesized and characterized in aqueous solution by surface tension measurements and fluorescence intensity of pyrene. These techniques evidence the existence of a threshold concentration, cac, below which a three layers film is formed at the air-water interface. At high concentrations, the intensity ratio of the vibronic peaks of pyrene, I1/I3, (= 0.81) is very close to published values for sodium cholate micelles, indicating that the probe is located in a region with a very low polarity and far from waterThe authors from USC thank the Ministerio de Ciencia y Tecnología (Project MAT2004-04606) and Xunta de Galicia (PGIDIT05PXIC26201PN) for financial suppor