Author, as appears in the article.: Rivoli A; Aragay G; Gimeno MC; Ballester P
Department: Química Analítica i Química Orgànica
URV's Author/s: Rivoli, Andrea
Keywords: Protonation constants Cytotoxicity studies Calix[4]pyrrole Anion receptors Acetylide gold(i) complexes photophysics nmr design cytotoxicity studies basis-sets anion receptors anion acetylide gold(i) complexes
Abstract: In this work, we report the synthesis and characterization of a mono-nuclear “two wall” aryl-extended calix[4]pyrrole receptor (2Au) decorated with an acetylide-gold(I)-PTA complex at its upper rim. We describe the1 H NMR titration experiments of 2Au and its “two wall” aryl-extended calix[4]pyrrole synthetic precursors: the non-symmetric mono-iodo-mono-ethynyl 2 and the symmetric bis-iodo 3 with TBACl in dichloromethane and acetone solution. In acetone solution, we use isothermal titration calorimetry (ITC) experiments to thermodynamically characterize the formed 1:1 chloride complexes and perform pair-wise competitive binding experiments. In both solvents, we measured a decrease in the binding constant of the mono-nuclear 2Au complex for chloride compared to the parent mono-iodo-mono-ethynyl 2. In turn, receptor 2 also shows a reduction in binding affinity for chloride compared to its precursor bis-iodo calix[4]pyrrole 3. The free energy differences (∆G) of the 1:1 chloride complexes cannot be exclusively attributed to their dissimilar electrostatic surface potential values either at the center of the meso-phenyl wall or its para-substituent. We conclude that solvation/desolvation processes play an important role in the stabilization of the chloride complexes. In acetone solution and in the presence of TBACl, 6Au, a reference compound for the acetylide Au(I)•PTA unit, produces a bis(alkynyl)gold(I) anionic complex [7Au]−. Thus, the observation of two separate sets of signals for the bound aromatic calix[4]pyrrole protons, when more than 1 equiv. of the salt is added, is assigned to the formation of the chloride complexes of 2Au and of the “in situ” formed calix[4]pyrrole anionic dimer [8Au]−. Finally, preliminary data obtained in cell viability assays of 2Au and 6Au with human cancer cells lines assign them with moderate activities showing that the calix[4]pyrrole unit is not relevant.
Thematic Areas: Inorganic chemistry Chemistry, inorganic & nuclear
licence for use: https://creativecommons.org/licenses/by/3.0/es/
Author's mail: andrea.rivoli@estudiants.urv.cat
Record's date: 2024-09-07
Papper version: info:eu-repo/semantics/publishedVersion
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: Inorganics. 10 (7):
APA: Rivoli A; Aragay G; Gimeno MC; Ballester P (2022). Chloride Binding Properties of a Macrocyclic Receptor Equipped with an Acetylide Gold(I) Complex: Synthesis, Characterization, Reactivity, and Cytotoxicity Studies. Inorganics, 10(7), -. DOI: 10.3390/inorganics10070095
Entity: Universitat Rovira i Virgili
Journal publication year: 2022
Publication Type: Journal Publications