Papers by giuseppe cassone
Applied Sciences
The complexation of metals in natural fluids, such as natural waters and biological fluids, is a ... more The complexation of metals in natural fluids, such as natural waters and biological fluids, is a key process in the context of environmental and biological phenomena [...]
The Journal of Physical Chemistry Letters
Here we prove that, in addition to temperature and pressure, another important thermodynamic vari... more Here we prove that, in addition to temperature and pressure, another important thermodynamic variable permits the exploration of the phase diagram of ammonia: the electric field. By means of (path integral) ab initio molecular dynamics simulations, we predict that, upon applying intense electric fields on ammonia, the electrofreezing phenomenon occurs, leading the liquid toward a novel ferroelectric solid phase. This study proves that electric fields can generally be exploited as the access key to otherwise-unreachable regions in phase diagrams, unveiling the existence of new condensed-phase structures. Furthermore, the reported findings have manifold practical implications, from the safe storage and transportation of ammonia to the understanding of the solid structures this compound forms in planetary contexts.
VizieR Online Data Catalog: HNCO in planetary atmospheres. (Ferus+, 2018)
VizieR Online Data Catalog, Jun 1, 2018
Free Energy Calculations of Electric Field-Induced Chemistry
Computational Approaches for Chemistry Under Extreme Conditions, 2019
The old and challenging problem of dealing with the interaction between condensed matter systems ... more The old and challenging problem of dealing with the interaction between condensed matter systems and intense external electric fields are currently evolving in an impressive way. In fact, the growth of the computational resources allows for accurate first-principles numerical calculations showing unprecedented predictive power. We review the phenomenological evidence that has recently emerged from state-of-the-art ab initio molecular dynamics simulations in describing how static electric fields can be exploited to manipulate matter and possibly design novel compounds or materials, obtain new exotic properties, and achieve more efficient reaction yields. In particular, we show the microscopic behavior of simple molecular liquids (water, methanol, and simple mixtures), under the action of static and homogeneous electric fields, showing different shades of the effects produced by the application of the latter. In addition, ab initio molecular dynamics approaches are coupled with advanced free energy methods, that currently represents a unique technique for adequately treating, reproducing, and predicting both molecular mechanisms and chemical reaction networks triggered when matter is exposed to the action of intense electric fields.
Chemical Research in Toxicology, 2020
Arsenic is one of the inorganic pollutants typically found in natural waters, and its toxic effec... more Arsenic is one of the inorganic pollutants typically found in natural waters, and its toxic effects on the human body are currently of great concern. For this reason, the search for detoxifying agents that can be used in a so-called "chelation therapy" is of primary importance. However, to the aim of finding the thermodynamic behavior of efficient chelating agents, extensive speciation studies, capable of reproducing physiological conditions in terms of pH, temperature, and ionic strength, are in order. Here, we report on the acid-base properties of meso-2,3-dimercaptosuccinic acid (DMSA) at different temperatures (i.e., T = 288.15, 298.15, 310.15, and 318.15 K). In particular, its capability to interact with As(III) has been investigated by experimentally evaluating some crucial thermodynamic parameters (ΔH and TΔS), stability constants, and its speciation model. Additionally, in order to gather information on the microscopic coordination modalities of As(III) with the functional groups of DMSA and, at the same time, to better interpret the experimental results, a series of state-of-the-art ab initio molecular dynamics simulations have been performed. For the sake of completeness, the sequestering capabilities of DMSAa simple dithiol ligandtoward As(III) are directly compared with those recently emerged from similar analyses reported on monothiol ligands.
Hydrogen-Bonded Systems Under Intense Electric Fields
Correlations in Condensed Matter under Extreme Conditions, 2017
Thermal effects induced on matter by electric fields are well known and largely understood [1].
Key Science Questions to be Addressed • What are the physical processes shaping planetary atmosph... more Key Science Questions to be Addressed • What are the physical processes shaping planetary atmospheres? • What are exoplanets made of? • How do planets and planetary systems form and evolve? Science Objectives (Chapter 2) Ariel Definition Study Report page 3 Foreword The concept of a mission devoted to atmospheric characterization of exoplanets through transit spectroscopy was first considered in Europe in 2007, shortly after the DARWIN proposal submitted to ESA for the first Cosmic Vision call for L-class missions was rejected because of the need for further scientific and technical developments. Following the decision, both ESA (EP-RAT panel report, October 2010) and the Exoplanetary Community (Blue Dot Team-Barcelona conference, September 2009) started a discussion to define a roadmap for exoplanetary research. Both groups concluded that an intermediate step was needed, both scientifically and technically, before the characterisation of Earth-like planets could be tackled, and recommended a transit spectroscopy mission as a first step to atmospheric characterisation. A short study was undertaken at ESTEC in the context of the ExoPlanet Roadmap Advisory Team mandate under the name ESM (Exoplanet Spectroscopy Mission). Following this study the Exoplanet Characterisation Observatory (EChO) was proposed and accepted for assessment phase study in the context of the ESA Cosmic Vision 2015-2025 programme M3 medium class mission opportunity. Although eventually not selected, the EChO study 1 allowed further development of the technical building blocks and the science case for an eventual transit spectroscopy mission. In response to the call for the next medium class opportunity, Cosmic Vision M4, a proposal was submitted in January 2015: the Atmospheric Remote-sensing InfraRed Large-survey (ARIEL). The mission was one of the three selected in June 2015 for study in a Phase 0/A, a competitive assessment phase 2. ARIEL was eventually selected as M4 in March 2018, and went into Phase B1, the definition study phase. The name of the mission has been changed to Ariel after selection. During Phase B1, the science case was studied in depth and consolidated under auspices of the Science Advisory Team, the bulk of the work being performed in a large number of science working groups in the Ariel Mission Consortium (AMC). The ESA Study Team and AMC reviewed the mission requirements, the technical design and analysis of the complete payload module (including telescope, instruments, guidance system and supporting infrastructure). The AMC developed an end-to-end performance simulator of the complete system. Two industrial contractors (Airbus Defence and Space, France and ThalesAlenia Space, France) reviewed the mission requirements, the technical design and analysis of the s/c and performed a programmatic analysis of the mission. Dedicated iterations were done in conjunction with both industrial and payload studies to harmonise the interfaces between the s/c and the payload, and to consolidate the payload accommodation. Recently the ESA Mission Adoption Review has successfully been concluded. This definition study report presents a summary of the very large body of work that has been undertaken on the Ariel mission over the 30-month period of the Ariel definition phase. As such, it represents the contributions of a large number of parties (ESA, industry, institutes and universities from 17 ESA member states, NASA CASE team), encompassing a very large number of people.
Molecules
Synthesis of RNA nucleobases from formamide is one of the recurring topics of prebiotic chemistry... more Synthesis of RNA nucleobases from formamide is one of the recurring topics of prebiotic chemistry research. Earlier reports suggest that thymine, the substitute for uracil in DNA, may also be synthesized from formamide in the presence of catalysts enabling conversion of formamide to formaldehyde. In the current paper, we show that to a lesser extent conversion of uracil to thymine may occur even in the absence of catalysts. This is enabled by the presence of formic acid in the reaction mixture that forms as the hydrolysis product of formamide. Under the reaction conditions of our study, the disproportionation of formic acid may produce formaldehyde that hydroxymethylates uracil in the first step of the conversion process. The experiments are supplemented by quantum chemical modeling of the reaction pathway, supporting the plausibility of the mechanism suggested by Saladino and coworkers.
Entropy
The search for the chemical origins of life represents a long-standing and continuously debated e... more The search for the chemical origins of life represents a long-standing and continuously debated enigma. Despite its exceptional complexity, in the last decades the field has experienced a revival, also owing to the exponential growth of the computing power allowing for efficiently simulating the behavior of matter—including its quantum nature—under disparate conditions found, e.g., on the primordial Earth and on Earth-like planetary systems (i.e., exoplanets). In this minireview, we focus on some advanced computational methods capable of efficiently solving the Schrödinger equation at different levels of approximation (i.e., density functional theory)—such as ab initio molecular dynamics—and which are capable to realistically simulate the behavior of matter under the action of energy sources available in prebiotic contexts. In addition, recently developed metadynamics methods coupled with first-principles simulations are here reviewed and exploited to answer to old enigmas and to pr...
Experimental Astronomy
Is there life beyond Earth? An ideal research program would first ascertain how life on Earth beg... more Is there life beyond Earth? An ideal research program would first ascertain how life on Earth began and then use this as a blueprint for its existence elsewhere. But the origin of life on Earth is still not understood, what then could be the way forward? Upcoming observations of terrestrial exoplanets provide a unique opportunity for answering this fundamental question through the study of other planetary systems. If we are able to see how physical and chemical environments similar to the early Earth evolve we open a window into our own Hadean eon, despite all information from this time being long lost from our planet's geological record. A careful investigation of the chemistry expected on young exoplanets is therefore necessary, and the preparation of reference materials for spectroscopic observations is of paramount importance. In particular, the deduction of chemical markers identifying specific processes and features in exoplanetary environments, ideally "uniquely". For instance, prebiotic feedstock molecules, in the form of aerosols and vapours, could be observed in transmission spectra in the near future whilst their surface deposits could be observed from reflectance spectra. The same detection methods also promise to identify particular intermediates of chemical and physical processes known to be prebiotically plausible. Is Ariel truly able to open a window to the past and answer questions concerning the origin of life on our planet and the universe? In this paper, we discuss aspects of prebiotic chemistry that will help in formulating future observational and data interpretation strategies for the Ariel mission. This paper is intended to open a discussion and motivate future detailed laboratory studies of prebiotic processes on young exoplanets and their chemical signatures.
Thermal Decomposition of Cocaine and Methamphetamine Investigated by Infrared Spectroscopy and Quantum Chemical Simulations
ACS Omega
Examination of thermal decomposition of street samples of cocaine and methamphetamine shows that ... more Examination of thermal decomposition of street samples of cocaine and methamphetamine shows that typical products detected in previous studies are accompanied by a wide palette of simple volatile compounds easily detectable by spectral techniques. These molecules increase smoke toxicity and their spectral detection can be potentially used for identification of drug samples by well-controlled laboratory thermolysis in temperature progression. In our study, street samples of cocaine and methamphetamine have been thermolyzed under vacuum over the temperature range of 350–650 °C. The volatile products (CO, HCN, CH4, C2H4, etc.) have been monitored by high-resolution Fourier-transform infrared (FTIR) spectrometry in this temperature range. The decomposition mechanism has been additionally examined theoretically by quantum-chemical calculations for the highest temperature achieved experimentally in our study and beyond. Prior to analysis, the street samples have also been characterized by FTIR, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and melting point determination.
Frontiers in Astronomy and Space Sciences
Influx of matter from impacting meteoroids and hydrothermal crater weathering are important facto... more Influx of matter from impacting meteoroids and hydrothermal crater weathering are important factors modifying the rock and mineral inventory of young planets undergoing heavy bombardment. These processes may have influenced not only the geochemical environment of, e.g., early Mars and other planets, but also the peculiar prebiotic chemistry on early Earth. Here, we present a synergistic experimental and computational investigation of the intermediates of chemical reactions of the formamide-based synthesis of canonical and non-canonical nucleobases by thermochemistry in hot hydrothermal crater environments. We put our findings into context with previously investigated plasma-initiated synthesis occuring directly during impact. Both processes result into the formation of all canonical nucleobases, hypoxanthine, purine, and into the onset of the simplest amino acid glycine. Furthermore, it turns out that radical species such as CN and H play a key role in the plasma-assisted impact che...
Applied Sciences, 2022
Arsenic is a well-known contaminant present in different environmental compartments and in human ... more Arsenic is a well-known contaminant present in different environmental compartments and in human organs and tissues. Inorganic As(III) represents one of the most dangerous arsenic forms. Its toxicity is attributed to its great affinity with the thiol groups of proteins. Considering the simultaneous presence in all environmental compartments of other common functional groups, we here present a study aimed at evaluating their contribution to the As(III) complexation. As(III) interactions with four (from di- to hexa-) carboxylic acids, five (from mono- to penta-) amines, and four amino acids were evaluated via experimental methods and, in simplified systems, also by quantum-mechanical calculations. Data were analyzed also with respect to those previously reported for mixed thiol-carboxylic ligands to evaluate the contribution of each functional group (-SH, -COOH, and -NH2) toward the As(III) complexation. Formation constants of As(III) complex species were experimentally determined, an...
European Space Agency, Nov 30, 2020
Key Science Questions to be Addressed • What are the physical processes shaping planetary atmosph... more Key Science Questions to be Addressed • What are the physical processes shaping planetary atmospheres? • What are exoplanets made of? • How do planets and planetary systems form and evolve? Science Objectives (Chapter 2) Ariel Definition Study Report page 3 Foreword The concept of a mission devoted to atmospheric characterization of exoplanets through transit spectroscopy was first considered in Europe in 2007, shortly after the DARWIN proposal submitted to ESA for the first Cosmic Vision call for L-class missions was rejected because of the need for further scientific and technical developments. Following the decision, both ESA (EP-RAT panel report, October 2010) and the Exoplanetary Community (Blue Dot Team-Barcelona conference, September 2009) started a discussion to define a roadmap for exoplanetary research. Both groups concluded that an intermediate step was needed, both scientifically and technically, before the characterisation of Earth-like planets could be tackled, and recommended a transit spectroscopy mission as a first step to atmospheric characterisation. A short study was undertaken at ESTEC in the context of the ExoPlanet Roadmap Advisory Team mandate under the name ESM (Exoplanet Spectroscopy Mission). Following this study the Exoplanet Characterisation Observatory (EChO) was proposed and accepted for assessment phase study in the context of the ESA Cosmic Vision 2015-2025 programme M3 medium class mission opportunity. Although eventually not selected, the EChO study 1 allowed further development of the technical building blocks and the science case for an eventual transit spectroscopy mission. In response to the call for the next medium class opportunity, Cosmic Vision M4, a proposal was submitted in January 2015: the Atmospheric Remote-sensing InfraRed Large-survey (ARIEL). The mission was one of the three selected in June 2015 for study in a Phase 0/A, a competitive assessment phase 2. ARIEL was eventually selected as M4 in March 2018, and went into Phase B1, the definition study phase. The name of the mission has been changed to Ariel after selection. During Phase B1, the science case was studied in depth and consolidated under auspices of the Science Advisory Team, the bulk of the work being performed in a large number of science working groups in the Ariel Mission Consortium (AMC). The ESA Study Team and AMC reviewed the mission requirements, the technical design and analysis of the complete payload module (including telescope, instruments, guidance system and supporting infrastructure). The AMC developed an end-to-end performance simulator of the complete system. Two industrial contractors (Airbus Defence and Space, France and ThalesAlenia Space, France) reviewed the mission requirements, the technical design and analysis of the s/c and performed a programmatic analysis of the mission. Dedicated iterations were done in conjunction with both industrial and payload studies to harmonise the interfaces between the s/c and the payload, and to consolidate the payload accommodation. Recently the ESA Mission Adoption Review has successfully been concluded. This definition study report presents a summary of the very large body of work that has been undertaken on the Ariel mission over the 30-month period of the Ariel definition phase. As such, it represents the contributions of a large number of parties (ESA, industry, institutes and universities from 17 ESA member states, NASA CASE team), encompassing a very large number of people.
Liquids, 2022
An experimental and computational study on the hydrolysis of Al3+ in aqueous solutions is here re... more An experimental and computational study on the hydrolysis of Al3+ in aqueous solutions is here reported. Speciation model and formation constants were determined by potentiometric titrations at T = 298.15 K, 0.1 ≤ I/mol L−1 ≤ 1 in aqueous NaCl, NaNO3, NaCl/NaNO3 solutions. The dependence of formation constants on ionic strength is reported in all the ionic media over the range of 0.1–1.0 mol L−1. Under the studied experimental conditions, the formation of Al3(OH)45+ and Al13(OH)327+ species is observed in all the investigated ionic media and ionic strengths. The formation constants of the species formed by Al3+ with Cl− were determined together with the dependence on the ionic strength. Moreover, with the aim of unveiling the molecular structure of the formed Al complexes, quantum-mechanical calculations and state-of-the-art ab initio molecular dynamics simulations under explicit solvation were executed. These computations show, for the first time, the highly cooperative role played...
Cr2o3-Doped Graphene Sensor for Early Diagnosis of Liver Cirrhosis: A First-Principles Study
SSRN Electronic Journal, 2022
One-Pot Hydrogen Cyanide-Based Prebiotic Synthesis of Canonical Nucleobases and Glycine Initiated by High-Velocity Impacts on Early Earth
Astrobiology, 2020
Chemical environments of young planets are assumed to be significantly influenced by impacts of b... more Chemical environments of young planets are assumed to be significantly influenced by impacts of bodies lingering after the dissolution of the protoplanetary disk. We explore the chemical consequences of impacts of these bodies under reducing planetary atmospheres dominated by carbon monoxide, methane, and molecular nitrogen. Impacts were simulated by using a terawatt high-power laser system. Our experimental results show that one-pot impact-plasma-initiated synthesis of all the RNA canonical nucleobases and the simplest amino acid glycine is possible in this type of atmosphere in the presence of montmorillonite. This one-pot synthesis begins with de novo formation of hydrogen cyanide (HCN) and proceeds through intermediates such as cyanoacetylene and urea.
Although the basic mechanism of the proton transfer (PT) phenomenon in water has been envisaged i... more Although the basic mechanism of the proton transfer (PT) phenomenon in water has been envisaged in 1806, nowadays does not exist a detailed theoretical framework that envelop the protolysis process. This phenomenon is at the base of the operation of hydrogen batteries, as well as of many biological processes. Via the Car-Parrinello Molecular Dynamics (CPMD) technique and by means of the application of an electric field (EF), part of this thesis has been devoted to the detailed study of PT in two ice phases: ice Ih and its ferroelectric counterpart, ice XI. Several previously unknown mechanisms have been shown. As an example, the role played by the oxygens when a PT occurs and the contribution due to (dis)order in assisting this process [1,2]. The PT phenomenon is also at the base of the functioning of some methanol-based energy converters such as Nafion membranes. To the aim of disclosing the intimate nature of PT in liquid methanol, a series of CPMD simulations have been carried ou...
Hydrogen-bonded systems under electric fields
Computer simulations rule our lives nowadays. From the scientific perspective, they allow for the... more Computer simulations rule our lives nowadays. From the scientific perspective, they allow for the knowledge of the most intimate details of matter at a sub-atomic (quantum) level both at a molecular and macroscopic level. When Hydrogen-bonded systems are subject to the action of strong electric fields, peculiar phenomena occur. These have a huge impact in our daily lives since, on one hand, most of the biochemical processes occur in water environments and in the presence of local electric fields and, on the other hand, many technological devices exploit molecular dissociation and proton transfer in order to produce "clean" energy from simple compounds (i.e., molecular hydrogen, methanol, etc.). Through the most advanced computing facilities, the full treatment of the fundamental field-induced processes of molecular dissociation and proton transfer is nowadays affordable and has led to draw a defined sketch of these phenomena with a molecular resolution, a fact almost unthi...
Applied Sciences, 2021
Although many H-bonded systems have been extensively investigated by means of infrared (IR) spect... more Although many H-bonded systems have been extensively investigated by means of infrared (IR) spectroscopy, the vibrational response to externally applied electric fields of polar liquids remains poorly investigated. However, local electric fields along with quantum-mechanical interactions rule the behavior of H-bonded samples at the molecular level. Among the many H-bonded systems, liquid methanol holds a key place in that it exhibits a very simple H-bond network where, on average, each molecule acts as a single H-bond donor and, at the same time, as a single H-bond acceptor. Here we report on the IR spectra emerging from a series of state-of-the-art ab initio molecular dynamics simulations of bulk liquid methanol under the action of static and homogeneous electric fields. In addition, the same analysis is here conducted in the absence of the external field and for different temperatures. Although some electric-field-induced effects resemble the response of other polar liquids (such ...
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Papers by giuseppe cassone