A5044934996- Spectroscopy and Quantum Chemical Studies
- Photochemistry and Electron Transfer Studies
- Photochromic and Fluorescence Chemistry
- DNA and Nucleic Acid Chemistry
- Photosynthetic Processes and Mechanisms
- Photoreceptor and optogenetics research
- Luminescence and Fluorescent Materials
- Advanced biosensing and bioanalysis techniques
- Organic Light-Emitting Diodes Research
- melanin and skin pigmentation
- Nonlinear Optical Materials Studies
- Porphyrin and Phthalocyanine Chemistry
- Synthesis of Organic Compounds
- Antioxidant Activity and Oxidative Stress
- Photoacoustic and Ultrasonic Imaging
- Advanced Fluorescence Microscopy Techniques
- Advanced Computing and Algorithms
- Gold and Silver Nanoparticles Synthesis and Applications
- Metabolism and Genetic Disorders
- Phytochemicals and Antioxidant Activities
- Radical Photochemical Reactions
- Photonic and Optical Devices
- Electrochemical Analysis and Applications
- Diamond and Carbon-based Materials Research
- Covalent Organic Framework Applications
Politecnico di Milano
2020-2025
University of Patras
2018-2024
Istituto di Fotonica e Nanotecnologie
2020-2023
Eumelanins play a crucial role as photoprotective agents for living organisms, yet the nature of stationary and transient species involved in light absorption deactivation processes remains controversial. Moreover, critical sub-100 fs time scale, which is key to characterization primary excited species, has remained unexplored. Here, we study eumelanin analogue polydopamine (PDA) employ combination steady-state optical spectroscopies reveal presence spectrally broad coupled electronic...
Internal conversion (IC) is a common radiationless transition in polyatomic molecules. Theory predicts that molecular vibrations assist IC between excited states, and ultrafast experiments can provide insight into their structure–function relationship. Here we elucidate the dynamics of vibrational modes driving process within Q band functionalized porphyrin molecule. Through combination multidimensional spectroscopies theoretical modeling, observe 60 fs Qy–Qx demonstrate it driven by...
Melanins play important roles in nature, particularly coloration and photoprotection, where interaction with light is essential. Biomimetic melanins represent an advantageous alternative to natural melanin for technological applications, sharing the same unique biocompatibility, as well optoelectronic properties. Allomelanin, derived from 1,8-dihydroxynaphthalene, has been reported exhibit even better photoprotective antioxidant properties than most studied example of biomimetic melanin,...
We investigate herein the excited state dynamics and symmetry breaking processes in three benzothiazole-derived two-photon absorbing chromophores by femtosecond fluorescence transient absorption (fs-TA) spectroscopies solvents of various polarity. The feature a quasi-quadrupolar D-π-A-π-D architecture comprised an electron-withdrawing benzothiazole core lateral triphenylamine donors (Qbtz-H), while acceptor strength central unit is enforced attached cyano groups (Qbtz-CN) electron-donating...
In this work, we show how the structural features of photoactive azobenzene derivatives can influence photoexcited state behavior and yield trans/cis photoisomerization process. By combining high-resolution transient absorption experiments in vis–NIR region quantum chemistry calculations (TDDFT RASPT2), address origin signals three poly-substituted push–pull azobenzenes with an increasing strength intramolecular interactions stabilizing planar trans isomer (absence H-bonds, methyl,...
One-dimensional (1D) linear nanostructures comprising sp-hybridized carbon atoms, as derivatives of the prototypical allotrope known carbyne, are predicted to possess outstanding mechanical, thermal, and electronic properties. Despite recent advances in synthesis, their chemical physical properties still poorly understood. Here, we investigate photophysics a polyyne (i.e., 1D chain with alternating single triple bonds), simplest model finite wire prototype sp-carbon-based chains. We perform...
The DNA polarity, i.e., the order in which nucleobases are connected together via phosphodiester backbone, is crucial for several biological processes. But, so far, there has not been experimental evidence regarding its effect on relaxation of electronic excited states. Here we examine this aspect two dinucleotides containing adenine and guanine: 5′-dApdG-3′ 5′-dGpdA-3′ water. We used different femtosecond transient absorption setups: one providing high temporal resolution broad spectral...
Molecular aggregation is a powerful tool for tuning advanced materials' photophysical and electronic properties. Here we present novel potential the aqueous-solvated aggregated state of boron dipyrromethene (BODIPY) to facilitate phototransformations otherwise achievable only under harsh chemical conditions. We show that photoinduced symmetry-breaking charge separation can itself initiate catalyst-free redox chemistry, leading selective α-C(sp
Abstract Excitation energy transfer (EET) is a key photoinduced process in biological chromophoric assemblies. Here we investigate the factors which can drive EET into efficient ultrafast sub-ps regimes. We demonstrate how coherent transport of electronic population could facilitate this water solvated NADH coenzyme and uncover role an intermediate dark charge-transfer state. High temporal resolution optical spectroscopy gives 54±11 fs time constant for process. Nonadiabatic quantum...
Using as showcase the DNA dinucleotide 5′-dTpdG-3′, in which thymine is located at 5′ end with respect to guanine, we study photoinduced electronic relaxation of coupled chromophores solution an unprecedented refinement.
Here, we use a simple and effective method to accomplish energy level alignment thus electron injection barrier control in organic light emitting diodes (OLEDs) with conventional architecture based on green emissive copolymer. In particular, series of functionalized zinc porphyrin compounds bearing π-delocalized triazine withdrawing spacers for efficient intramolecular transfer different terminal groups such as glycine moieties their peripheral substitutes are employed thin interlayers at...
Abstract In the quest to decipher chain of life from molecules cells, biological and biophysical questions being asked increasingly demand techniques that are capable identifying specific biomolecules in their native environment, can measure biomolecular interactions quantitatively, at smallest possible scale space time, without perturbing system under observation. The interaction light with offers a wealth phenomena tools be exploited drive this progress. This Roadmap is written...
Benzothiazole is among prominent electron-withdrawing heteroarene moieties used in a variety of π-conjugated molecules. Its relative orientation with respect to the principal dipole vector(s) chromophores derived thereof crucial, affecting photophysical and nonlinear optical properties. Here we compare photophysics ultrafast dynamics dipolar octupolar molecules comprising triphenylamine electron-donating core, ethynylene linker(s) benzothiazole acceptor(s) having matched or mismatched (with...
The thermal motion of fluorescent organic nanoparticles is affected by the excitation intensity even at a low irradiance regime. displacement an individual nanoparticle increases linearly with irradiation (Photothermal Motion).
There is compelling evidence that the absorption of low-energy UV radiation directly by DNA in solution generates guanine radicals with quantum yields are strongly dependent on secondary structure. Key players this unexpected phenomenon photo-induced charge transfer (CT) states, which an electric has been transferred from one nucleobase to another. The present work examines factors affecting population these states during electronic relaxation. It focuses two dinucleotides opposite...
We present a combined approach integrating chemical synthesis, computational methods and advanced ultrafast spectroscopy to explore the properties of triphenodioxazine diimides (TPDODI). The TPDODI derivative shows significant redshifted absorption (λmax...
Multidimensional spectroscopies reveal a two-step process in biomimetic supracomplex for oxygen evolution. A sub-ps charge-separation within the light-sensitizer moiety is followed by hole transfer from catalyst counterpart, forming productive charges.
Multidimensional spectroscopies unveil the presence of vibronic coupling within Q-states in a free-base porphyrin. High-frequency and tuning modes drive ultrafast internal conversion track excited state structural evolution.