Cristina Puzzarini

University of Bologna | UNIBO · "Giacomo Ciamician" Department of Chemistry CHIM

We report the study of three structural isomers of phenylpropiolonitrile (3-phenyl-2-propynenitrile, C6H5-C3N) containing an alkyne function and a cyano group, namely ortho-, meta-, and para-cyanoethynylbenzene (HCC-C6H4-CN). The pure rotational spectra of these species have been recorded at room temperature in the millimeter-wave domain using a ch...

A combined experimental and theoretical study has been carried out on 4-fluoro-threonine, the only naturally occurring fluorinated amino acid. Fluorination of the methyl group significantly increases the conformational complexity with respect to the parent amino acid threonine. The conformational landscape has been characterized in great detail, wi...

Radioastronomy is a powerful tool for the discovery of molecules in space but it requires molecular species to be polar. The observation of apolar species can be however enabled by protonation, which occurs from reaction with the abundant H 3 + ion whenever the proton affinity of the species under consideration is greater than that of H2. This prop...

Aminoacetonitrile is an interstellar molecule with a prominent prebiotic role, already detected in the chemically-rich molecular cloud Sagittarius B2(N) and postulated to be present in the atmosphere of the largest Saturn's moon, Titan. To further support its observation in such remote environments and laboratory experiments aimed at improving our...

The interplay of high-resolution rotational spectroscopy and quantum-chemical computations plays an invaluable role in the investigation of biomolecule building blocks in the gas phase. However, quantum-chemical methods suffer from unfavorable scaling with the dimension of the system under consideration. While a complete characterization of flexibl...

Interstellar molecules are often highly reactive species, which are unstable under terrestrial conditions, such as radicals, ions and unsaturated carbon chains. Their detection in space is usually based on the...

Rotational spectroscopy is the technique of choice for investigating molecular structures in the gas phase. Indeed, rotational constants are strongly connected to the geometry of the molecular system under consideration. Therefore, they are powerful tools for assessing the accuracy that quantum chemical approaches can reach in structural determinat...

Gas-phase molecular spectroscopy is a natural playground for accurate quantum-chemical computations. However, the molecular bricks of life (e.g., DNA bases or amino acids) are challenging systems because of the unfavorable scaling of quantum-chemical models with the molecular size (active electrons) and/or the presence of large-amplitude internal m...

A non-linear spectroscopic study of the HDO molecule is performed in the wavelength range of 1.36–1.42 μ m using noise-immune cavity-enhanced optical-heterodyne molecular spectroscopy (NICE-OHMS). More than 100 rovibrational Lamb dips are recorded, with an experimental precision of 2–20 kHz, related to the first overtone of the O–H stretch fundamen...

Context. Substituted methanimines and ethylenes have been identified in the interstellar medium. Therefore, allylimine (CH 2 =CH–CH=NH) represents a promising candidate for a new interstellar detection. Aims. The goal of the present work is to perform a comprehensive laboratory investigation of the rotational spectrum of allylimine in its ground vi...

Two quantum effects can enable reactions to take place at energies below the barrier separating reactants from products: tunnelling and intersystem crossing between coupled potential energy surfaces. Here we show that intersystem crossing in the region between the pre-reactive complex and the reaction barrier can control the rate of bimolecular rea...

Polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic nitrogen heterocycles (PANHs) are important and ubiquitous species in space. However, their accurate structural and spectroscopic characterization is often missing. To fill this gap, we exploit the so-called "Lego brick" approach [Melli et al., J. Phys. Chem. A, 2021, 125, 9904] to eva...

Several interstellar molecules are highly reactive unsaturated carbon chains, which are unstable under terrestrial conditions. Laboratory studies in support of their detection in space thus face the issue of how to produce these species and how to correctly model their rotational energy levels. In this work, we introduce a general approach for prod...

The formyl cation (HCO+) is one of the most abundant ions in molecular clouds and plays a major role in the interstellar chemistry. For this reason, accurate collisional rate coefficients for the rotational excitation of HCO+ and its isotopes due to the most abundant perturbing species in interstellar environments are crucial for non-local thermal...

The formyl cation (HCO+) is one of the most abundant ions in molecular clouds and plays a major role in the interstellar chemistry. For this reason, accurate collisional rate coefficients for the rotational excitation of HCO+ and its isotopes due to the most abundant perturbing species in interstellar environments are crucial for non-local thermal...

An integrated experimental-computational strategy for the accurate characterization of the conformational landscape of flexible biomolecule building blocks is proposed. This is based on the combination of rotational spectroscopy with quantum-chemical computations guided by artificial intelligence tools. The first step of the strategy is the conform...

The "gold standard" for obtaining accurate equilibrium structures is the so-called semi-experimental (SE) approach, which exploits the structural information contained in rotational constants. Within the SE approach, ground-state rotational constants-accurately obtained from high-resolution spectroscopic studies-are computationally corrected in ord...

Context. Theories of the origins of life propose that early cell membranes were synthesised from amphiphilic molecules simpler than phospholipids, such as fatty alcohols. The discovery in the interstellar medium (ISM) of ethanolamine, the simplest phospholipid head group, raises the question whether simple amphiphilic molecules are also synthesised...

The processes and reactions that led to the formation of the first biomolecules on Earth play a key role in the highly debated theme of the origin of life. Whether the first chemical building blocks were generated on Earth (endogenous synthesis) or brought from space (exogenous delivery) is still unanswered. The detection of complex organic molecul...

Theories on the origins of life propose that early cell membranes were synthesized from amphiphilic molecules simpler than phospholipids such as fatty alcohols. The discovery in the interstellar medium (ISM) of ethanolamine, the simplest phospholipid head group, raises the question whether simple amphiphilic molecules are also synthesized in space....

We present the first detection of ( Z )-1,2-ethenediol, (CHOH) 2 , the enol form of glycolaldehyde, in the interstellar medium toward the G+0.693−0.027 molecular cloud located in the Galactic Center. We have derived a column density of (1.8 ± 0.1) × 10 ¹³ cm ⁻² , which translates into a molecular abundance with respect to molecular hydrogen of 1.3...

We present the first detection of ($Z$)-1,2-ethenediol, (CHOH)$_2$, the enol form of glycolaldehyde, in the interstellar medium towards the G+0.693-0.027 molecular cloud located in the Galactic Center. We have derived a column density of (1.8$\pm$0.1)$\times$10$^{13}$ cm$^{-2}$, which translates into a molecular abundance with respect to molecular...

Being N-substituted unsaturated species, azabutadienes are molecules of potential relevance in astrochemistry, ranging from the interstellar medium to Titan's atmosphere. 2-Azabutadiene and butadiene share a similar conjugated π system, thus allowing investigation of the effects of heteroatom substitution. More interestingly, 2-azabutadiene can be...

“Who” and how? In this simple question the complexity of the interstellar chemistry is encapsulated. “Who” refers to what molecules are present in the interstellar medium (ISM) and “how” to the mechanisms that led to their formation. While the large number of molecules discovered in the ISM (∼250) demonstrates the rich chemistry occurring there, a...

Prebiotic sugars are thought to be formed on primitive Earth by the formose reaction. However, their formation is not fully understood and it is plausible that key intermediates could have formed in extraterrestrial environments and subsequently delivered on early Earth by cometary bodies. 1,2-Ethenediol, the enol form of glycolaldehyde, represents...

The investigation of reaction mechanisms in the interstellar medium requires the evaluation of reaction rates and branching ratios, which can be effectively obtained in the framework of the ab-initio transition state/master equation formalism. However, the reliability of this approach relies on the computation of accurate reaction enthalpies and ac...

In light of its ubiquitous presence in the interstellar gas, the chemistry and reactivity of the HCO+ ion requires special attention. The availability of up-to-date collisional data between this ion and the most abundant perturbing species in the interstellar medium is a critical resource in order to derive reliable values of its molecular abundanc...

Phosphorous-containing molecules have a great relevance in prebiotic chemistry in view of the fact that phosphorous is a fundamental constituent of biomolecules, such as RNA, DNA, and ATP. Its biogenic importance has led astrochemists to investigate the possibility that P-bearing species could have formed in the interstellar medium (ISM) and subseq...

Spectroscopic techniques can probe molecular systems non-invasively and investigate their structure, properties and dynamics in different environments and physico-chemical conditions. Different spectroscopic techniques (spanning different ranges of the electromagnetic field) and their combination can lead to a more comprehensive picture of investig...

In recent years, phosphorus monoxide (PO), an important molecule for prebiotic chemistry, has been detected in star-forming regions and in the comet 67P/Churyumov-Gerasimenko. These studies have revealed that, in the interstellar medium (ISM), PO is systematically the most abundant P-bearing species, with abundances that are about one to three time...

The far-infrared spectrum of HC3N has been recorded at high resolution between 70 and 500 cm−1using synchrotron radiation. Four prominent features, i.e., ν7, ν6−ν7, ν4−ν6, and 2ν7 have been identified in the spectrum together with many associated hot bands. In addition, rotational transitions for the interacting v4=v7=1, (v6=2,v7=1), (v5=1,v7=2), a...

In light of its ubiquitous presence in the interstellar gas, the chemistry and reactivity of the HCO+ ion requires special attention. The availability of up-to-date collisional data between this ion and the most abundant perturbing species in the interstellar medium is a critical resource in order to derive reliable values of its molecular abundanc...

The accurate determination of equilibrium structures for isolated molecules plays a central role in the evaluation and interpretation of stereoelectronic, thermodynamic, and spectroscopic properties. For small semi-rigid systems, state-of-the-art quantum-chemical computations can rival the most sophisticated experimental results. For larger molecul...

The 1:1 benzofuran-formaldehyde complex has been chosen as model system for analyzing π → π * interactions in supramolecular organizations involving heteroaromatic rings and carbonyl groups. A joint “rotational spectroscopy - quantum chemistry” strategy unveiled the dominant role of π → π * interactions in tuning the intermolecular interactions of...

A recently developed model chemistry (denoted as junChS [Alessandrini et al J. Chem. Theory Comput. 2020, 16, 988-1006]) has been extended to the employment of explicitly-correlated (F12) methods. This led us to propose a family of effective, reliable and parameter-free schemes for the computation of accurate interaction energies of molecular compl...

The 1:1 benzofuran‐formaldehyde complex has been chosen as model system for analyzing π → π * interactions in supramolecular organizations involving heteroaromatic rings and carbonyl groups. A joint “rotational spectroscopy ‐ quantum chemistry” strategy unveiled the dominant role of π → π * interactions in tuning the intermolecular interactions of...

Huge efforts have recently been taken in the derivation of accurate compilations of rovibrational energies of water, one of the most important reference systems in spectroscopy. Such precision is desirable for all water isotopologues, although their investigation is challenged by hyperfine effects in their spectra. Frequency-comb locked noise-immun...

The cover image describes the “journey” among different states of matter of creatinine. In particular, the ice cubes, representing the solid state, highlight the presence of the only amino‐isomer structure of creatinine. The same is also found for the “melt” ice (the puddle) which represents the aqueous solution. Finally, the “smoke” representing t...

In recent years, phosphorus monoxide (PO) -- an important molecule for prebiotic chemistry -- has been detected in star-forming regions and in the comet 67P/Churyumov-Gerasimenko. These studies have revealed that, in the interstellar medium, PO is systematically the most abundant P-bearing species, with abundances that are $\sim$1-3 times greater t...

The established pillars of computational spectroscopy are theory and computer based simulations. Recently, artificial intelligence and virtual reality are becoming the third and fourth pillars of an integrated strategy for the investigation of complex phenomena. The main goal of the present contribution is the description of some new perspectives f...

Cyclopropanecarboxaldehyde (CPCA) has two main conformers, syn and anti, that are renowned for being very close in energy. The stability order of these two main species is constantly reversed by changing the level of theory or the experimental technique employed in its determination. The anti conformer is predicted to be the most favoured in conden...

New spectroscopic experiments and state‐of‐the‐art quantum‐chemical computations of creatinine in different aggregation states unequivocally unveiled a significant tuning of tautomeric equilibrium by the environment: from the exclusive presence of the amine tautomer in the solid state and aqueous solution to a mixture of different conformers of ami...

4-Fluoro-threonine, the only fluoro amino acid of natural origin discovered so far, is an interesting target for both synthetic and theoretical investigations. In this work, we lay the foundation for spectroscopic characterization of 4-fluoro-threonine. First, we report a diastereoselective synthetic route, which is suitable to produce synthetic ma...

Published high-resolution rotation-vibration transitions of H₂¹²C¹⁶O the principal isotopologue of methanal, are analyzed using the MARVEL (Measured Active Rotation-Vibration Energy Levels) procedure. The literature results are augmented by new, high-accuracy measurements of pure rotational transitions within the ground, ν_{3}, ν_{4}, and ν_{6} vib...

The first high-resolution infrared spectra of CH2D³⁷Cl have been investigated in the region 650 – 1100 cm⁻¹ where the lowest fundamental bands ν5 (826.2626 cm⁻¹), ν6 (708.4307 cm⁻¹), and ν9 (986.3405 cm⁻¹) occur. These vibrations perturb each other by different weak interactions and the v5 = 1 and v6 = 1 states were treated according to a model whi...

The ubiquitous role of water and its amphiprotic nature call for a deeper insight into the physical–chemical properties of hydrogen-bonded complexes formed with building blocks of biomolecules. In this work, the semiexperimental (SE) approach combined with the template model (TM) protocol allowed the accurate determination of the equilibrium struct...

The perspectives opened by modern ground-based infrared facilities and the forthcoming James Webb Telescope mission have brought a great attention to the ro-vibrational spectra of simple interstellar molecules. In this view, and because of the lack of accurate spectroscopic data, we have investigated the infrared spectrum of deuterated cyanoacetyle...

Cycloserine has in common with isoxazolidines the saturated five-membered ring, which is an important scaffold for drug design, exhibiting diverse biological activities. The most remarkable feature of these compounds is the presence of the N-O bond framed in a cyclic moiety. The lack of an accurate characterization of this structural feature in an...

Quantifying molecular abundances of astrochemical species is a key step towards the understanding of the chemistry occurring in the interstellar medium. This process requires a profound knowledge of the molecular energy levels, including their structure resulting from weak interactions between nuclear spins and the molecular rotation. With the aim...

An interdisciplinary review of the chemical literature that points to a unifying scenario for the origin of life, referred to as the Primordial Multifunctional organic Entity (PriME) scenario, is provided herein. In the PriME scenario it is suggested that the Insoluble Organic Matter (IOM) in carbonaceous chondrites, as well as interplanetary dust...

Published high-resolution rotation-vibration transitions of \spec{h212c16o}, the principal isotopologue of methanal, are analyzed using the MARVEL (Measured Active Rotation-Vibration Energy Levels) procedure. The literature results are augmented by new, high-accuracy measurements of pure rotational transitions within the ground, $\nu_3$, $\nu_4$, a...

Phosphorus is of particular interest in astrochemistry because it is a biogenic element together with hydrogen, carbon, nitrogen, oxygen, and sulfur. However, the chemical evolution of such element in the interstellar medium (ISM) is still far from an accurate characterization, with the chemistry of P-bearing molecules being poorly understood. To p...

A gas-phase formation route is proposed for the recently detected propargylimine molecule. In analogy to other imines, such as cyanomethanimine, the addition of a reactive radical (C2H in the present case) to methanimine (CH2NH) leads to reaction channels open also in the harsh conditions of the interstellar medium. Three possible isomers can be fo...

The most stable isomer of the 1:1 complex formed by 2,2,2-trifluoroacetophenone and water has been characterized by combining rotational spectroscopy in supersonic expansion and state-of-the-art quantum-chemical computations. In the observed isomer, water plays the double role of proton donor and acceptor, thus forming a seven-membered ring with 2,...