Piero Ugliengo

Piero Ugliengo (PU) graduated in Chemistry in 1981 at the University of Torino and worked two years at the CSI Piemonte computing center as a system manager. In 1983, PU joined the Physical Chemistry Institute of the University of Torino, as a researcher and in 1992, he was appointed as associate professor in Structural Chemistry and, in 2015, as full professor of Physical Chemistry at the Department of Chemistry. PU is also an active member of the Nanostructured Interfaces and Surfaces (NIS) since its foundation.

Institutional charges. PU has been teaching Director of: i) Master’s degree in Metodologie Chimiche Avanzate (2009-2012); ii) Master’s degree in Chimica (2015-2020); iii) Deputy Director with responsibility for the teaching organization of the department (2016-2021); iv) Member of the Doctorate School; v) member of the steering committee of the physical chemistry division of the Società Chimica Italiana.

Very short summary of the scientific activities. PU used quantum mechanical ab initio methods grounded on the rigorous solution of the Schrödinger equation for molecules, surfaces, and solid matter. PU interests span a rather wide range of system and properties, all of which have, as a common base, the interactions between molecules and surfaces. Few examples are, adsorption on oxide surfaces, catalysis by microporous materials, ceramic biomaterials and their interaction with soft matter, drug delivery by mesoporous silica-based materials and, in more recent years, prebiotic chemistry at interstellar grains and mineral surfaces.

Highlighted cases. Among the studied systems, the following are those reflecting most the approach and interests of PU.

Modeling the interstellar icy dust mantle and their role in the adsorption.

Interstellar dust particles are made of an amorphous silicate/carbon core covered by a multilayers of water ice. The detailed structure of the amorphous ice is unknown and many terrestrial laboratory experiments have been carried out to model it. Computer models are a promising alternative to define fine structural details and, until now, have been limited using very small water clusters, envisaging few water molecules to model the ice mantle. We have recently proposed a new mantle icy model (ACO-FROST) adopting up to 1000 water molecules, which is capable to include, in one model only, all possible adsorption sites available on an amorphous ice surface. We have proved the validity of this model by modeling within an ab-initio approach, the adsorption features of NH3, H2O, CH3OH, H2S, OCS and SO2 in which a complete binding energy distribution was predicted to be adopted for interpreting the experimental thermal desorption spectra. These papers are the result of the ACO project, in collaboration with UGA and UAB.

Prebiotic formation of complex organic molecules in the astrochemical context.Aminoacids are the building blocks of proteins and can be easily formed through the Strecker mechanism in the Miller-Urey prebiotic scenario. However, despite the glycine detection in comets, like the 67/P and meteorites, no clear mechanism has been proposed for its synthesis in the interstellar space. PU and coworkers at UAB, have proposed two mechanisms for the glycine synthesis in molecular clouds, excluding the possibility of a Strecker-like mechanism in a dark molecular cloud while suggesting the role of UV and cosmic rays for the formation of glycine on models of interstellar icy grains. The simplest molecule containing the peptide bond is formamide (FA). It has been claimed in the literature, that FA can be the source of many important prebiotic constituents due to its reactivity in the harsh condition of the primordial Earth. FA has been detected in the interstellar spaces, and PU and coworkers at UAB and UNIPG, have established a possible mechanism, operative in the interstellar molecular clouds, in which the FA formation, starting from HCN/CN species, is catalyzed by the water molecules of the icy interstellar grains, opening a route to understand its encapsulation in comets.

Other important processes occur at the surfaces of the icy grain core (made of olivine) and mantle (made by water ice). PU and coworkers at UGA and UAB universities, have modelled the formation of molecular hydrogen H2, the most abundant molecule in the Universe, showing a specific role of the Fe ions of the olivine matrix, in catalyzing, via a redox process, the formation of H2. The same process has been studied also at the water icy grains, by carefully analyzing the transfer of the H2 formation energy towards the ice grain, elucidating the mechanism of desorption operated by the grain heating. Due to the very low temperature of the interstellar medium (10 K), radical/molecule and radical/radical encounters are the only one occurring free from kinetic barriers. PU, and especially the coworkers at the UAB and UGA, have addressed many key radical reactions at the grain icy mantle, to understand the role of the surface in diffusion and catalysis of hydrogenation (by atomic H) of many relevant radical species.

Formation of nucleic acid bases by HCN reaction on olivines

It is well known that HCN has been detected in both the interstellar medium and in comets tails. It is also a key molecule in the Strecker reactions of the Urey-Miller experiment. Furthermore, as proved in the sixties by Joan Orò, it can polymerize to give adenine, one of the heterocycle molecule key in many biological relevant molecules (ATP, DNA, RNA). We have studied, both experimentally and by computer modeling, the fate of HCN on crystalline and amorphous forsterite, as models of the core interstellar dust and the comets core. This work has been in collaboration with UAB.

Role of mineral Schreibersite as a source of phosphorous in the prebiotic era.

A detailed study of the reactivity of Schreibersite (Fe2NiP) a mineral of meteoritic nature, towards water has been carried out by computer modeling. Bulk and all possible surfaces have been modeled to assess the most stable morphological crystallographic shape. Reaction with water has also been studied to assess the availability of phosphorous in the form of phosphate, able to phosphorylate organic molecules in the prebiotic era. This work has received support by ASI through the MIGLIORA project in collaboration with UNIPG.

Prebiotic peptide bond formation by mineral surfaces.The building block of peptides and nucleic acids can be formed through processes described above or in different primordial Earth environment. However, despite the aminoacids availability, their polymerization requires a condensation reaction (water elimination), thermodynamically disfavored and kinetically hindered in the water rich environment of a primordial planet. One possibility to circumvent this hurdle was proposed in the 50’s by D. Bernal, who hypotized the role of the mineral surfaces in both stabilizing the newly formed peptide and in lowering the kinetic barrier. PU and coworkers at the UAB, have addressed this problem computationally, by designing a model of the feldspar mineral surface (the most common mineral on Earth’s crust), showing that the condensation reaction to give the simplest oligopeptide diglycine, was thermodynamic and kinetically favored once glycine and its products are adsorbed at the mineral surface. The fine atomistic details of the interplay between Lewis (securing the aminoacid to the surface) and Brønsted (activating the carbonyl bond towards nucleophilic attack) have been elucidated by the simulation. An even simpler mineral surfaces, represented by a specifically prepared silica surface, was shown to be able to catalyze the formation of long glycine oligomers (up to 11 members) by the experimental work carried out by the late Prof. Gianmario Martra and his group at the Department of Chemistry. PU, in collaboration with coworkers at UAB, after a long preparatory work, fully clarified the mechanism, in which specific silanol (SiOH) pairs, were found to catalyze the condensation reaction in the very same way as an inorganic “enzyme pocket”.

Silica surfaces and their interaction with molecules. Silica (SiO2) exhibits both crystalline and amorphous phases. Amorphous silica is a key material used in a wide variety of problems, from metal-catalyst support, as a chromatographic support, up to drug delivery system in its mesoporous form. Many of these properties are related to the silica surface features, a topic not yet fully understood. PU has developed realistic atomistic models for both amorphous and mesoporous silica, which can be treated at quantum mechanical level using hybrid functionals, like B3LYP-D3 or PBE0- D3, capable of high accuracy on high-performance computing resources, contributing to the tuning of the massive parallel CRYSTAL program. The coordinates of these models have been made available to the scientific community and accessed more than 2000 times (data from ResearchGate). These models have been used to study the interaction and delivery of commons molecular drugs (aspirin and ibuprofen) in a nanomedicine context.

Biomaterial/soft-matter interaction. Essential to discover the role of mineral surface on the adsorbed soft matter is the interaction of biopolymers with biomaterials of inorganic nature. Hydroxyapatite (HA), a key constituent of bones and teeth, has been the target of intense studies by PU and coworkers. Questions like: “Does a peptide conformation be influenced by the interaction with the HA surface functionalities?” and “Will the interaction of the peptide mediated by the water molecules?” have been addressed through atomistic simulations. A carefully designed short a-helix polyglicine peptide and a periodic model of collagen peptide interacting with the HA surfaces have been used to answer the above questions. The adopted full quantum mechanical approach, overcome the usual limitation of the molecular mechanics force fields usually employed to deal with systems of that complexity.

Software development. PU develops the molecular graphic program MOLDRAW downloaded by more than 7000 researchers worldwide. PU also collaborate with Prof. Robert Hanson (Sant Olaf College, Northfield, MN 55057, USA) on the development of the JSMOL and J-ICE molecular graphics programs.

Bibliometric impact and tutoring. As a result of this scientific trajectory, PU co-authorships 281 papers on peer-reviewed international journals (with an ISI-WOK h-index of 56, about 11300 citations with an average citation/paper of 40). PU has given about 65 talks in international meetings, seminars, and events of scientific interest. PU is also active in public engagement activity. PU supervised 11 PhD thesis, 6 temporary research fellowships one PostDoc granted by the Spanish Ramón Areces Foundation and hosted 8 PhD students from abroad for short periods.

Scientific projects. PU has actively contributed to several funded research projects (INSTM- Nanostructured oxides materials, INSTM-Interface between silica and biomolecules, MIUR-Silica and cellular response, MIUR-Interface silica/biomolecules, FP7-Hydrogen storage, M-Era-Net- Bioactive materials, MIUR astrochemistry (2018), ITN-H2020 ACO AstroChemical Origin project, MUR PRIN Astrochemistry beyond the second period elements (2020), (MIGLIORA) ASI 2024-2027, PNRR CN1-SPOKE 7 Materials and Molecular Sciences and has been the container of high- performance computing resources projects through many ISCRA (Cineca) projects and one PRACE (EU).

Scientific collaborations. Beside collaborating with colleagues of the spectroscopic experimental group at the Chemistry Department of the Torino University, PU collaborated with: i) Daresbury Laboratory in England in 1985, 1986 and 1987 on molecular modeling of adsorbates on amorphous silica surfaces; ii) Humboldt University in Berlin (1992-94) on modeling zeolites and silica surfaces; iii) Universitat Autonoma de Barcelona (2004-2005, 2011), as invited professor, on ab initio modeling of the role of mineral surfaces and amorphous silica in the origin of life; iv) Universite' de Pierre et Marie Curie (Paris) (2009) to write a special issue of the Chemical Society Review devoted to prebiotic chemistry; v) Dipartimento di Scienze Biologiche, Geologiche e Ambientali at the Univeristy of Bologna on hydroxyapatites based biomaterials (2011-2013); vi) Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia and Dipartimento di Scienza Applicata e Tecnologia at the Politecnico di Torino on simulation of bioglasses and drug delivery by mesoporous silica (2013-2015); vii) Department of Chemistry, University of Perugia on interstellar grain chemistry. Since 2004 he is regularly visiting the group of Mariona Sodupe and Albert Rimola at the Universitat Autonoma de Barcelona (for at least one month a year) as a foreign member of the group; viii) Universidad de Barcelona, with Stefan Bromley on computer modeling of the interstellar grains. PU is actively involved in the ACO project in tight collaboration with the astronomers of the Cecilia Ceccarelli’s group of the IPAG, Observatoire de Grenoble, Universitè J.Fourier de Grenoble on astrochemical problems.

Membership, reviewer service. PU is member of the: i) international advisory board of the Horizons in Hydrogen Bond Research and it has organized the; ii) the advisory board of Royal Society Journal CrystEngChem. iii) Royal Society of Chemistry; iv) Physical Chemistry Division of the American Chemical Society. In 2010 PU organized the international NIS Colloquium “First chemical steps towards the origin of life”. PU is member of: i) the physical chemistry division of the Italian Chemical Society; ii) of the National Consortium of Materials Science and Technology (INSTM); iii) the Nanostructured Interfaces and Surfaces (NIS) center of Excellence of the University of Torino; iv) member of the Management Committee of COST Action CM1401 “Our Astro-Chemical History; v) Associate Editor for Astrochemistry of Frontiers in Astronomy and Space Science Journal; vi) The Italian National Project of Astrobiology—Life in Space—Origin, Presence, Persistence of Life in Space, from Molecules to Extremophiles.

Congress organization. PU has organized the following conferences: i) 2001-Torino, XV conference on Horizons in Hydrogen Bond Research; ii) 2003-Torino, webmaster of the XXI Italian Chemistry Society Conference in Torino; ii) 2010-Torino, International NIS Colloquium "First chemical steps towards the origin of life"; iii) 2015-Torino, CHITEL (Congresso Chimici Teorici di Espressione Latina); iv) 2020-Torino, International colloquium "Machine Learning Meets Chemistry"; v) 2021-Torino, International Conference on “Chemical processes in Solar-type star forming regions”; vi) 2023-Torino National Congress of the Physical Chemistry Division of the Società Chimica Italiana.

Ten representative papers in the astrochemistry and prebiotic chemistry context (last 3 years)

(1) Ferrero, S.; Ceccarelli, C.; Ugliengo, P.; Sodupe, M.; Rimola, A. Formation of Interstellar Complex Organic Molecules on Water-rich Ices Triggered by Atomic Carbon Freezing. ApJ 2024, 960, 22 DOI: 10.3847/1538-4357/ad0547.(2) Pantaleone, S.; Corno, M.; Rimola, A.; Balucani, N.; Ugliengo, P. Computational Study on the Water Corrosion Process at Schreibersite (Fe2 NiP) Surfaces: from Phosphide to Phosphates. ACS Earth Space Chem. 2023 DOI: 10.1021/acsearthspacechem.3c00167.

(3) Tinacci, L.; Germain, A.; Pantaleone, S.; Ceccarelli, C.; Balucani, N.; Ugliengo, P. Theoretical water binding energy distribution and snowline in protoplanetary disks. ApJ 2023, 951, 32 DOI: 10.3847/1538-4357/accae8.(4) Perrero, J.; Enrique-Romero, J.; Ferrero, S.; Ceccarelli, C.; Podio, L.; Codella, C.; Rimola, A.; Ugliengo, P. Binding Energies of Interstellar Relevant S-bearing Species on Water Ice Mantles: A Quantum Mechanical Investigation. ApJ 2022, 938, 158 DOI: 10.3847/1538-4357/ac9278.

(5) Tinacci, L.; Germain, A.; Pantaleone, S.; Ferrero, S.; Ceccarelli, C.; Ugliengo, P. Theoretical distribution of the ammonia binding energy at interstellar icy grains: A new computational framework. ACS Earth Space Chem. 2022, 6, 1514–1526 DOI: 10.1021/acsearthspacechem.2c00040.

(6) Germain, A.; Tinacci, L.; Pantaleone, S.; Ceccarelli, C.; Ugliengo, P. Computer Generated Realistic Interstellar Icy Grain Models: Physicochemical Properties and Interaction with NH3. ACS Earth Space Chem. 2022, 6, 1286–1298 DOI: 10.1021/acsearthspacechem.2c00004.(7) Das, A.; Bizzocchi, L.; Ugliengo, P. Editorial: exploring the chemical universe. Front. Astron. Space Sci. 2022, 9 DOI: 10.3389/fspas.2022.839076.

(8) Santalucia, R.; Pazzi, M.; Bonino, F.; Signorile, M.; Scarano, D.; Ugliengo, P.; Spoto, G.; Mino, L. From gaseous HCN to nucleobases at cosmic silicate dust surface: an experimental insight into the onset of prebiotic chemistry in space. Phys. Chem. Chem. Phys. 2022, 24, 7224–7230 DOI: 10.1039/D1CP05407D.

(9) Pantaleone, S.; Corno, M.; Rimola, A.; Balucani, N.; Ugliengo, P. Water Interaction with Fe2NiP Schreibersite (110) Surface: a Quantum Mechanical Atomistic Perspective. J. Phys. Chem. C Nanomater. Interfaces 2022, 126, 2243–2252 DOI: 10.1021/acs.jpcc.1c09947.(10) Pantaleone, S.; Corno, M.; Rimola, A.; Balucani, N.; Ugliengo, P. Ab initio computational study on Fe2 NiP schreibersite: bulk and surface characterization. ACS Earth Space Chem. 2021 DOI: 10.1021/acsearthspacechem.1c00083.