Invited Speakers

Raman spectroscopy: Molecular characterization to monitor changing materials and materials in change

“… the character of the scattered radiation enables us to obtain an insight into the ultimate structure of the scattering substance,” Sir C. V. Raman stated during his Nobel Lecture.

Raman spectroscopy provides molecular and structural information through the vibrational modes of the scattering substance. It is a remarkably versatile technique, particularly suited to characterizing, monitoring, and validating materials, products, and processes. Moreover, Raman spectroscopy allows us not only to characterize materials as they are, but also to follow how they change under different environments and operating conditions.

This lecture will introduce the nature of the Raman effect and its fundamental concepts. The main experimental configurations will be presented. Particular attention will be paid to practical aspects of Raman measurements, including excitation wavelength, spectral resolution, calibration, fluorescence, and other experimental factors that determine spectral quality and interpretation.

The Raman effect and the resulting spectra are strongly dependent on experimental variables, making spectral harmonization essential for obtaining reliable, comparable, and quantitatively interoperable data. Drawing on the experience gained within the European CHARISMA project, we will discuss strategies for Raman calibration, instrument twinning, spectral harmonization, and the organization of experimental data according to FAIR principles. These aspects are particularly relevant to extending the reliable use of Raman spectroscopy across laboratories, instruments, and scientific disciplines.

The second part of the lecture will focus on the ability of Raman spectroscopy to monitor materials in change, particularly under reactive environments (in situ and operando methods). Catalysis provides an illustrative example, since catalysts are dynamic materials whose structure and chemical state may evolve during reaction. Raman spectroscopy can help us understand both how the catalyst changes while it operates and how the catalyst transforms the reacting molecules. Selected examples from heterogeneous catalysis will illustrate the use of in situ and operando Raman spectroscopy to follow catalyst evolution, identify surface species, and relate molecular and structural changes to catalytic performance.

The lecture will provide a general perspective on Raman spectroscopy, from its basic principles and experimental practice to its use as a tool for understanding materials and their transformations under working conditions.

Raman Spectroscopic Analysis of Pharmaceutical- and Biomaterials

Traditional analytical chemistry often struggles with the trade-off between deep molecular insight and labor-intensive sample preparation. Raman spectroscopy disrupts this trade-off by providing a "low-prep, high-insight" platform for pharmaceutical and biomedical research. This presentation highlights the strategic application of different Raman modalities to solve diverse chemical puzzles in biomaterial analysis: i) the implementation of hyperspectral Raman chemical imaging to map and quantify active ingredients in tablets without dissolution, ii) sensing biomarkers and drugs in body fluids and iii) analysis of drug-target interactions directly in cells to resolve complex molecular structures of biocrystals and related drug binding modes.

Through these examples, I will demonstrate how the combination of tailored Raman techniques and complementary computational tools enables rapid, non-destructive elucidation of complex material properties in both pharmacological and bioanalytical contexts.

From Molecular Interactions to Plasmonic Enhancement: An Atomistic Perspective on Raman Spectroscopy

Raman spectroscopy provides a powerful tool for probing molecular structure and interactions in complex environments, including functional materials and plasmonic nanostructures. A reliable interpretation of Raman and Resonance Raman spectra requires computational approaches capable of bridging molecular-scale interactions, environmental fluctuations, and the spectroscopic response of the system [1-4].

In this contribution, we present an atomistic and multiscale modeling perspective on the key factors governing Raman signatures in complex environments. We discuss the role of an accurate quantum-mechanical description of the molecular target, the explicit incorporation of target–environment interactions, and the treatment of specific interactions such as hydrogen bonding. Particular emphasis is placed on dynamical sampling of the molecular environment, which captures structural heterogeneity and its impact on vibrational frequencies and spectral line shapes [1, 3, 4]. We then extend this framework to plasmonic nanostructures, addressing the incorporation of electromagnetic enhancement and molecule–surface interactions in the atomistic modeling of Surface-Enhanced Raman Scattering (SERS) [1, 2].

Selected applications spanning solvated molecules and plasmonic systems illustrate how microscopic structure, environmental effects, and light–matter interactions shape Raman spectra, highlighting the potential of computational spectroscopy to support the interpretation and molecular-level understanding of Raman signals in complex materials [1-4].

References

(1) Giovannini, T.; Gomez, S.; Cappelli, C. Modeling Raman Spectra in Complex Environments: From Solutions to Surface-Enhanced Raman Scattering. J. Phys. Chem. Lett. 2025, 16, 3106–3121.

(2) Lafiosca, P.; Nicoli, L.; Bonatti, L.; Giovannini, T.; Corni, S.; Cappelli, C. QM/Classical Modeling of Surface Enhanced Raman Scattering Based on Atomistic Electromagnetic Models. J. Chem. Theory Comput. 2023, 19, 3616–3633.

(3) Giovannini, T.; Cappelli, C. Continuum vs Atomistic Approaches to Computational Spectroscopy of Solvated Systems. Chem. Commun. 2023, 59, 5644–5660.

(4) Giovannini, T.; Egidi, F.; Cappelli, C. Molecular Spectroscopy of Aqueous Solutions: A Theoretical Perspective. Chem. Soc. Rev. 2020, 49, 5664–5677.

Electronic and vibrational processes in soft materials

Electronic and vibrational processes govern the response properties of soft materials. Atomistic and first-principles simulations, combined with vibrational spectroscopy, provide key insights into structure–property relationships and elucidate elusive physicochemical mechanisms at the molecular scale.

In this talk, I will present selected case studies illustrating how molecular modelling and vibrational spectroscopy (IR and Raman) can unravel the interplay between structure, charge transport and response properties in soft functional materials. I will focus on two classes of systems: organic conjugated materials and hybrid organic/metal-halide molecules and polymers.

I will discuss how nuclear motion and electron–phonon coupling shape the response of these materials, governing polaron transport in organic systems and mechano-luminochromic behaviour in hybrid systems.