I studied chemistry at the Università degli Studi di Padova (Italy), where I obtained my Bachelor’s degree in 2012 and my Master’s degree in 2014 after a five-months internship at the Spanish National Research Council in Madrid (Spain). Then I moved to the Universidad Autónoma de Madrid (Spain), where I completed my PhD in Organic Chemistry under the supervision of Prof. Tomás Torres focusing on the synthesis and study of novel subphthalocyanine-based systems for solar energy conversion applications. During this period, I realized predoctoral stays in the laboratory of Prof. A. Osuka at Kyoto University (Japan), working on the preparation of metalated subporphyrin complexes, and in the laboratory of Prof. D. M. Guldi at Friedrich Alexander University Erlangen-Nürnberg (Germany), where I studied the photophysics of porphyrinoid-containing multicomponent systems. Since August 2021, I am a Marie Curie postdoctoral researcher in Prof. Bert Meijer's group at the Eindhoven University of Tech
EDUCATION
Bachelor Degree in Chemistry (University of Padua, Italy)
Master Degree in Chemistry (University of Padua, Italy)
Optical resolution via chiral auxiliaries of curved subphthalocyanine aromatics Giulia Lavarda, Lara Tejerina, Tomás Torres, M. Victoria Martínez-Díaz Chemical Science, 2024 We report the optical resolution of inherently chiral, bowl-shaped subphthalocyanines (SubPcs) using BINOL-based chiral auxiliaries. Additionally, unprecedented bowl-to-bowl inversion of the SubPc macrocycle is observed under specific conditions.
Long-Lived Triplets from Singlet Fission in Pentacene-Decorated Helical Supramolecular Polymers Giulia Lavarda, Ashish Sharma, Marko Beslać, Stef A. H. Jansen, Stefan C. J. Meskers, et al. Journal of the American Chemical Society, 2024 Singlet fission (SF), which involves the conversion of a singlet excited state into two triplet excitons, holds great potential to boost the efficiency of photovoltaics. However, losses due to triplet-triplet annihilation hamper the efficient harvesting of SF-generated triplet excitons, which limits an effective implementation in solar energy conversion schemes. A fundamental understanding of the underlying structure-property relationships is thus crucial to define design principles for cutting-edge SF materials, yet it remains elusive. Herein, we harness helical supramolecular polymers decorated with pentacene side groups to elucidate intermolecular SF dynamics in solution and promote the formation of long-lived mobile triplets. By leveraging the hydrogen bonding-driven assembly of benzene-1,3,5-tricarboxamide (BTA) cores into one-dimensional scaffolds, we direct the organization of appended pentacene motifs into long-range ordered helical frameworks. Dynamic interactions between weakly coupled SF pendants mediate singlet conversion within hundreds of picoseconds, affording triplet quantum yields well above 100%. Moreover, analysis of triplet dynamics with a Monte Carlo simulation model reveals that triplet diffusion along the supramolecular fibers is favored over annihilation, resulting in independent triplets exhibiting considerably slow decay on the time scale of tens of microseconds. The molecular packing within the assembly is tuned by subtle changes in monomer design to increase the rate and efficiency of SF while ensuring exceptionally long-lived mobile triplets, allowing to maintain triplet quantum yields exceeding 100% for at least 100 ns. This work opens new opportunities to exploit self-assembled supramolecular polymers as functional templates to achieve long-lived SF-generated triplets.
Supramolecular polymerization and bulk properties relationship in ester-functionalized N-annulated perylenediimides Lucía López-Gandul, Giulia Lavarda, Bart W. L. van den Bersselaar, Ghislaine Vantomme, E. W. Meijer, et al. Chemical Science, 2024 The self-assembly and bulk properties of NPDIs 1–4 are reported. In solution, increasing the length of the tether changes the mechanism from cooperative (1–3) to isodesmic (4). Bulk studies show an odd-even effect depending on the linker.
Supramolecular Polymerization as a Tool to Reveal the Magnetic Transition Dipole Moment of Heptazines Fan Xu, Hao Su, Joost J. B. van der Tol, Stef A. H. Jansen, Youxin Fu, et al. Journal of the American Chemical Society, 2024 Heptazine derivatives have attracted significant interest due to their small S1-T1 gap, which contributes to their unique electronic and optical properties. However, the nature of the lowest excited state remains ambiguous. In the present study, we characterize the lowest optical transition of heptazine by its magnetic transition dipole moment. To measure the magnetic transition dipole moment, the flat heptazine must be chiroptically active, which is difficult to achieve for single heptazine molecules. Therefore, we used supramolecular polymerization as an approach to make homochiral stacks of heptazine derivatives. Upon formation of the supramolecular polymers, the preferred helical stacking of heptazine introduces circular polarization of absorption and fluorescence. The magnetic transition dipole moments for the S1 ← S0 and S1 → S0 are determined to be 0.35 and 0.36 Bohr magneton, respectively. These high values of magnetic transition dipole moments support the intramolecular charge transfer nature of the lowest excited state from nitrogen to carbon in heptazine and further confirm the degeneracy of S1 and T1.
Tunable emission from H-type supramolecular polymers in optical nanocavities Giulia Lavarda, Anton M. Berghuis, Kripa Joseph, Joost J. B. van der Tol, Shunsuke Murai, et al. Chemical Communications, 2024 Tunable emission from H-type supramolecular polymers prepared by self-assembly of tetraphenylethylene-based monomers is achieved by harnessing the surface lattice resonances of dielectric TiO2 nanoparticles.
Recent advances in subphthalocyanines and related subporphyrinoids Giulia Lavarda, Jorge Labella, M. Victoria Martínez-Díaz, M. Salomé Rodríguez-Morgade, Atsuhiro Osuka, et al. Chemical Society Reviews, 2022 Subporphyrinoids constitute a class of extremely versatile and attractive compounds. Herein, a comprehensive review of the most recent advances in the fundamentals and applications of these cone-shaped aromatic macrocycles is presented.
Preparation, Supramolecular Organization, and On-Surface Reactivity of Enantiopure Subphthalocyanines: From Bulk to 2D-Polymerization Jorge Labella, Giulia Lavarda, Leyre Hernández-López, Fernando Aguilar-Galindo, Sergio Díaz-Tendero, et al. Journal of the American Chemical Society, 2022 The development of chiral materials is severely limited by the challenge to achieve enantiopure derivatives with both configurational stability and good optoelectronic properties. Herein we demonstrate that enantiopure subphthalocyanines (SubPcs) fulfill such demanding requirements and bear the prospect of becoming components of chiral technologies. Particularly, we describe the synthesis of enantiopure SubPcs and assess the impact of chirality on aspects as fundamental as the supramolecular organization, the behavior in contact with metallic surfaces, and the on-surface reactivity and polymerization. We find that enantiopure SubPcs remarkably tend to organize in columnar polar assemblies at the solid state and highly ordered chiral superstructures on Au(111) surfaces. At the metal interface, such SubPcs are singled out by scanning tunneling microscopy. DFT calculations suggest that SubPcs undergo a bowl-to-bowl inversion that was shown to be dependent on the axial substituent. Finally, we polymerize by means of on-surface synthesis a highly regular 2D, porous and chiral, π-extended polymer that paves the way to future nanodevice fabrication.
Z-α1-antitrypsin polymers impose molecular filtration in the endoplasmic reticulum after undergoing phase transition to a solid state Joseph E. Chambers, Nikita Zubkov, Markéta Kubánková, Jonathon Nixon-Abell, Ioanna Mela, et al. Science Advances, 2022 Misfolding of secretory proteins in the endoplasmic reticulum (ER) features in many human diseases. In α 1 -antitrypsin deficiency, the pathogenic Z variant aberrantly assembles into polymers in the hepatocyte ER, leading to cirrhosis. We show that α 1 -antitrypsin polymers undergo a liquid:solid phase transition, forming a protein matrix that retards mobility of ER proteins by size-dependent molecular filtration. The Z-α 1 -antitrypsin phase transition is promoted during ER stress by an ATF6-mediated unfolded protein response. Furthermore, the ER chaperone calreticulin promotes Z-α 1 -antitrypsin solidification and increases protein matrix stiffness. Single-particle tracking reveals that solidification initiates in cells with normal ER morphology, previously assumed to represent a healthy pool. We show that Z-α 1 -antitrypsin–induced hypersensitivity to ER stress can be explained by immobilization of ER chaperones within the polymer matrix. This previously unidentified mechanism of ER dysfunction provides a template for understanding a diverse group of related proteinopathies and identifies ER chaperones as potential therapeutic targets.
