Person:
Cabañas Poveda, Albertina

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First Name
Albertina
Last Name
Cabañas Poveda
URI
https://hdl.handle.net/20.500.14352/76101
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Física
Area
Química Física
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2018 - 20204
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Author: Cuadra Mendoza, Isaac Alfonso ×

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Now showing 1 - 4 of 4
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    Production and Characterization of a new Copper(II) Propanoate-Isonicotinamide Adduct obtained via Slow Evaporation and using Supercritical CO2 as an Antisolvent
    (Crystal Growth and Design, 2019) Cuadra Mendoza, Isaac Alfonso; Martínez Casado, Francisco Javier; Rodriguez Cheda, Jose A.; Redondo, M.I.; Pando, Concepción; Cabañas Poveda, Albertina
    A new adduct of isonicotinamide (INA) with copper(II) propanoate [Cu(C3)2] was prepared [Cu2(C3)4(INA)4] using two different methods. This type of compound shows high fungicidal activity. Solvent evaporation from ethanol rendered crystals suitable for single-crystal X-ray diffraction. Furthermore, a new semicontinuous method capable of simultaneous crystallization and micronization of the adduct using supercritical CO2, the supercritical antisolvent technique (SAS), was also assessed. Crystals were characterized using powder X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis coupled with mass spectrometry, scanning electron microscopy, and microelemental analysis. In the adduct, two copper(II) ions are coordinated through two bridging and two chelating carboxylates to the propanoate anions forming approximately a plane. Each metal ion is then coordinated with the pyridine nitrogen of two different INA molecules that behave as monodentate ligands. The amide groups of the INA form H-bonds with other amide and carboxylate groups forming a molecular crystal with a three-dimensional H-bond arrangement of the binuclear units. With the SAS technique, crystals 100-fold smaller than those obtained by slow evaporation were obtained, proving SAS as a suitable method for mixed-ligand complexes preparation with reduced particle size and therefore expected bioavailability enhancement.
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    Project number: 242
    Laboratorio integrado de prácticas de simulación de fundamentos y procesos químicos con fluidos supercríticos
    (2019) Calvo Garrido, Lourdes; Cabañas Poveda, Albertina; Pando García-Pumarino, Concepción; García Baonza, Valentín; González Mac-Dowell, Luis; Tirado Armesto, Diego Felipe; Cuadra Mendoza, Isaac Alfonso; Menéndez Carbajosa, Alicia Marta; Calvo Garrido, María Lourdes
    El objetivo del proyecto ha sido crear un laboratorio integrado de prácticas de simulación relacionadas con fundamentos termodinámicos y procesos con fluidos supercríticos, destinado a los alumnos de Química e Ingeniería Química.
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    Cocrystallization of the anticancer drug 5-fluorouracil and coformers urea, thiourea or pyrazinamide using supercritical CO2 as an antisolvent (SAS) and as a solvent (CSS)
    (The Journal of Supercritical Fluids, 2020) Cuadra Mendoza, Isaac Alfonso; Cabañas Poveda, Albertina; Rodríguez Cheda, José Antonio; Türk, MIchael; Pando García-Pumarino, Concepción
    Co-crystals of 5-fluorouracil (5-Fu) and the coformers urea, thiourea and pyrazinamide (PZA) were attempted for the first time through the supercritical antisolvent (SAS) and the cocrystallization with supercritical solvent (CSS) techniques. SAS operational conditions were temperature (313 K), pressure (7.0–15.0 MPa) and 5-Fu concentration in methanol (5 and 2.5 mg/mL). Coformer concentration was always in the desired stoichiometric ratio. Co-crystals were characterized using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Pure 5-Fu-urea cocrystals were obtained via SAS at 313 K and 8.0 MPa using a 5 mg/mL 5-Fu solution. All other SAS conditions studied led to 5-Fu homocrystal impurities. For comparison purposes 5-Fu, urea and thiourea were also processed by SAS. CSS produced a mixture of co-crystals and homocrystals only when supercritical CO2 was modified with methanol. Advantages and disadvantages of the two supercritical cocrystallization techniques are discussed.
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    Polymorphism in the co-crystallization of the anticonvulsant drug carbamazepine and saccharin using supercritical CO2 as an anti-solvent
    (The Journal of Supercritical Fluids, 2018) Cuadra Mendoza, Isaac Alfonso; Cabañas Poveda, Albertina; Rodríguez Cheda, José Antonio; Pando García-Pumarino, Concepción
    1:1 Co-crystals of carbamazepine (CBZ) and saccharin (SAC) were obtained for the first time through the supercritical anti-solvent (SAS) technique based on using supercritical CO2 as anti-solvent. The capability of SAS to produce the desired polymorphic form (two polymorphs are known) was assessed. Operational conditions investigated were temperature (40.0 and 60.0 °C), pressure (10.0 and 15.0 MPa), solvent choice and coformer concentration in the organic solution (CBZ: 30 and 15 mg/mL; SAC: stoichiometric ratio). Co-crystals were characterized in terms of crystallinity and coformers interactions. No homocrystals were present. Using methanol, at 40.0 °C polymorph I was obtained with yields up to 65%; whilst at 60.0 °C a mixture of polymorphs was obtained. Mixtures of polymorphs were also obtained in the ethanol and dichloromethane experiments at the studied conditions while the dimethylsulfoxide experiments failed to produce any co-crystal polymorph. For comparison purposes, pure CBZ and SAC were also processed by SAS.