https://hdl.handle.net/10259/6185 2026-04-17T17:33:28Z https://hdl.handle.net/10259/7561 Targets, Mechanisms and Cytotoxicity of Half-Sandwich Ir(III) Complexes Are Modulated by Structural Modifications on the Benzazole Ancillary Ligand Acuña, M. Isabel; Rubio Antolin, Ana Rosa; Martínez Alonso, Marta; Busto Vázquez, Natalia; Rodríguez, Ana María; Davila Ferreira, Nerea; Smythe, Carl; Espino Ordóñez, Gustavo; García Ruiz, Begoña; Domínguez, Fernando Cancers are driven by multiple genetic mutations but evolve to evade treatments targeting specific mutations. Nonetheless, cancers cannot evade a treatment that targets mitochondria, which are essential for tumor progression. Iridium complexes have shown anticancer properties, but they lack specificity for their intracellular targets, leading to undesirable side effects. Herein we present a systematic study on structure-activity relationships of eight arylbenzazole-based Iridium(III) complexes of type [IrCl(Cp*)], that have revealed the role of each atom of the ancillary ligand in the physical chemistry properties, cytotoxicity and mechanism of biological action. Neutral complexes, especially those bearing phenylbenzimidazole (HL1 and HL2), restrict the binding to DNA and albumin. One of them, complex 1[C,NH-Cl], is the most selective one, does not bind DNA, targets exclusively the mitochondria, disturbs the mitochondria membrane permeability inducing proton leak and increases ROS levels, triggering the molecular machinery of regulated cell death. In mice with orthotopic lung tumors, the administration of complex 1[C,NH-Cl] reduced the tumor burden. Cancers are more vulnerable than normal tissues to a treatment that harnesses mitochondrial dysfunction. Thus, complex 1[C,NH-Cl] characterization opens the way to the development of new compounds to exploit this vulnerability 2022-12-01T00:00:00Z https://hdl.handle.net/10259/7407 Photocatalytic Aerobic Dehydrogenation of N-Heterocycles with Ir(III) Photosensitizers Bearing the 2(2′-Pyridyl)benzimidazole Scaffold Echevarría Poza, Igor; Vaquero Gutiérrez, Mónica; Manzano, Blanca R.; Jalón Sotés, Félix Ángel; Quesada Pato, Roberto; Espino Ordóñez, Gustavo Photoredox catalysis constitutes a very powerful tool in organic synthesis, due to its versatility, efficiency, and the mild conditions required by photoinduced transformations. In this paper, we present an efficient and selective photocatalytic procedure for the aerobic oxidative dehydrogenation of partially saturated N-heterocycles to afford the respective N-heteroarenes (indoles, quinolines, acridines, and quinoxalines). The protocol involves the use of new Ir(III) biscyclometalated photocatalysts of the general formula [Ir(C^N)2(N^N′)]Cl, where the C^N ligand is 2- (2,4-difluorophenyl)pyridinate, and N^N′ are different ligands based on the 2-(2′-pyridyl)benzimidazole scaffold. In-depth electrochemical and photophysical studies as well as DFT calculations have allowed us to establish structure−activity relationships, which provide insights for the rational design of efficient metal-based dyes in photocatalytic oxidation reactions. In addition, we have formulated a dual mechanism, mediated by the radical anion superoxide, for the above-mentioned transformations. 2022-04-01T00:00:00Z https://hdl.handle.net/10259/6382 Tuning the properties of ionic liquids by mixing with organic solvents: The case of 1-butyl-3-methylimidazolium glutamate with alkanols Ghazipour, H.; Gutiérrez Vega, Alberto; Alavianmehr, M. M.; Hosseini, S. M.; Aparicio Martínez, Santiago Binary liquid mixtures of 1-butyl-3-methylimidazolium glutamate acid ([bmim][glu]) with alkanols (1-propanol, isobutanol and 1,2-propanediol) are studied in the full composition range as a function of temperature using a combined experimental and computational chemistry approach. Experimental thermophysical information as well as derived excess and mixing properties allowed to characterize these complex liquid mixtures in terms of deviation from ideality as well their relationships with the developed intermolecular forces and changes with the type of considered alkanols. Theoretical studies using quantum chemistry and classical molecular dynamics simulations provided nanoscopic characterization on the studied fluids, with particular attention to the extension and nature of hydrogen bonding and its effects on molecular arrangements and mixed fluids’ properties. The reported study provides a micro and macroscopic characterization of the considered aminoacid-based ionic liquid mixtures, thus contributing to the knowledge of sustainable ionic liquid systems mixed with organic solvents for fine tuning properties and developing task specific applications. 2022-02-01T00:00:00Z https://hdl.handle.net/10259/6208 Insights on biodiesel blends with alkanol solvents Ghazipour, H.; Gutiérrez Vega, Alberto; Mohammad-Aghaie, D.; Alavianmehr, M. M.; Hosseini, S. M.; Aparicio Martínez, Santiago Thermophysical properties of mixtures of fatty acid esters with alkanols were measured in the whole composition range as a function of temperature for understanding features of biodiesel blends. Excess and mixing properties calculated from experimental measurements allowed to quantify and analyze the intermolecular forces in the considered systems. Likewise, molecular modelling studies using quantum chemistry and classical molecular dynamics simulations led to a detailed characterization of these systems at the nanoscopic level. The nature of hydrogen bonding in these liquid mixtures was particularly analyzed from macroscopic properties and theoretical modelling results. The reported experimental and computational study allowed to infer the relationships between the intermolecular forces and additional microscopic features and the mixtures macroscopic properties, which are relevant for the development and characterization of biodiesels. The non-ideality behavior of the studied systems shows relevant changes in hydrogen bonding structuring upon mixing, with the fatty acid esters largely disrupting the alcohols self-association, although ester – alcohol hydrogen bonding is developed, this type of interactions is remarkably weaker than those for alcohols. Therefore, the studied biodiesel blends macroscopic properties may be tuned and controlled through the amount of alcohols in the mixtures and rooted on its effect on hydrogen bonding. 2021-06-01T00:00:00Z