Solid state condensed molecular materials, or ices, are ubiquitous in our galaxy, particularly in regions where star and planet formation dominates. After H₂, molecular ices like H₂O, CO, CO₂ and CH₃OH are the most abundant molecules in star-forming regions. These ices are also the key reservoir of volatile elements (C, H , N, O, S), and the potential origins of so-called complex organic molecules 9COMs), the organic chemicals with more than 6 atoms that represent the increasing chemical complexity that emerges as star-formation progresses. With the launch of JWST, a space IR telescope, in 2022, astronomers have a new ëye" on the cold icy star-forming regions of our galaxy, particularly the pre-stellar clouds, protostars and protoplanetary discs where ices dominate the IR spectra. In this talk I'll present the first results from the JWST ICEAGE Early Release Science Programme (http://jwst-iceage.org/). The first results show the showcase the exquisite data quality from JWST and reveal the diversity of icy chemistry found in dark regions of molecular clouds. We present a new budget for the C, O, N, and S budgets of ices in the cloud and our understanding of the chemical pathways by which ices form, including evidence for early formation of methanol, the simplest COM, in water rich ice mixtures and a potential detection of ethanol in this cloud. All of this is only possible by combining observational spectroscopy with modelling and experiments from the laboratory. I'll highlight the work ongoing across the ICEAGE team, in gas-phase sub-mm observations, astrochemical modelling and laboratory spectroscopy, to enable us to extract the maximum understanding and analysis of the ICEAGE spectra. One aspect of this is the potential to map the distribution of ices in space, utilising slit-less spectroscopy techniques. Our ability to exploit JWST to extract and compare 100's of ice spectra concurrently will be briefly shown - with the first "look" ice map data from the ERS ICEAGE programme.

Phosphorus is an element of particular interest from the astronomical point of view, since it is an essential element for life. However, not many P-containing molecules have been found in space, both because a low cosmic abundance of P (P/H ∼ 3×10⁻⁷) and because P is thought to be considerably depleted on dust grains. In particular, phosphine (PH₃), has only been observed in the atmospheres of Jupiter and Saturn, and, outside of the solar system, in the circumstellar envelope of IRC +10216.M. Agúndez et al. 2014 ApJL 790 L27hosphine ice is thought to be a constituent of comets, and, in the ISM, a source for gas phase P upon sublimation from icy grains. In this work the infrared spectra of PH₃ ices and PH₃:H₂O  ice mixtures have been studied both experimentally and theoretically. PH₃ ices were generated by vapour deposition at 10 K.B. Maté et al. 2021 ApJ 909 123t was found that the amorphous to crystalline transition takes place between 35 and 40 K. A theoretical modelling of crystalline PH₃ and of a tentative amorphous PH₃ solid phase, as well as of amorphous PH₃:H₂O  ice mixtures, has been performed. The infrared spectroscopic information given in this work is expected to be useful for the detection and quantification of PH₃ in astrophysical ices.Work supported by the spanish Ministry of Science and Innovation (MCINN) through grant PID2020-113084GB-I00.html:<hr /><h3>Footnotes: M. Agúndez et al. 2014 ApJL 790 L27P B. Maté et al. 2021 ApJ 909 123I Work supported by the spanish Ministry of Science and Innovation (MCINN) through grant PID2020-113084GB-I00.

Even though the interaction between polar water and hydrophobic molecules such as PAHs is very subtle, soot or dust particles do play a key role in the water nucleation in atmospheres and in interstellar space. To understand this process and predict their structures and properties, an accurate understanding of the shallow potential energy surface between PAH-water clusters is essential. Infrared spectroscopy is a particularly well-suited technique to study the PES of such ground-state systems. Previous IR studies, as well as complementary microwave work, established that the hydrogen bonding within the water network is more important than the interactions between water substrate. However, most infrared studies focused on the XH stretch region, which only indirectly reveals information on weaker, non-covalent interactions. This study, focusing on neutral naphthalene interacting with up to three water molecules, shows that far-IR radiation can probe the intermolecular potential directly and reveals notable effects of the substrate on the water clusters. Despite the clusters being produced in a cold environment, the weak interactions necessitate their spectra to be interpreted within a dynamic, rather than a static framework. Purely intermolecular vibrational modes are identified and changes of the far-IR water libration modes upon complexation are investigated. Both show the perturbative effect of the substrate on water and the dynamics between PAH and water.

Silicates are ubiquitously found as small dust grains throughout the universe. These particles are frequently subject to high-energy processes and subsequent condensation in the interstellar medium (ISM), where they are broken up into many ultra-small silicate fragments. Such fragments can be astrochemically relevant for the formation and dissociation of small molecules, such as H₂, H₂O, O₂, or CO₂. In our work, we use methods that are well established in the field of cluster chemistry and physics and are now transferred to addressing astrochemically relevant materials: infrared multiple-photon dissociation (IR-MPD) spectroscopy combined with ion trap and flow tubes reaction studies. With this approach we aim to gain insight into the geometric structure of ultra-small silica and silicate fragments as well as their reactive and catalytic properties. In particular, I will present first results on the infrared spectrum of the pyroxene monomer MgSiO₃, its surprisingly strong interaction with molecular oxygen, and potential initial steps of particle nucleation. Furthermore, I will address the interaction of ultra-small silica clusters with water leading to the hydroxylation of the clusters and a characteristic band in the IR-MPD spectrum, which was not detected for bulk silica.

In 2021, the first pure PAH molecule, indene, was finally detected in the cold pre-stellar core TMC-1\footnote{Cernicharo et al. 2021, A\&A 649, L15; Bukhardt et al. 2021, ApJL, 913:L18}, with an estimated gas-phase abundance of 1 - 1.6 10$^{-9}$ with respect to H$_{2}$. The observed high relative abundance of indene in cold molecular clouds raises the question about the cycling of this molecule between the gas and the ice mantles of dust grains, and further modeling and laboratory data are required to understand these processes. The present work is focused on the IR spectroscopy of solid phases of indene at low temperatures that, to our knowledge, have not been reported previously. Using the same experimental setup described in our previous works on urea\footnote{Mat\'{e} et al. 2021, PCCP, 23, 22344; Herrero et al.2022, MNRAS 517, 1058–1070}, IR spectra of vapor deposited amorphous and crystalline indene and of indene mixtures with water ice have been recorded. Solid structures and vibrational spectra have been calculated using density functional theory and the results of the calculations have been used for the assignment of the measured IR spectra. Experimental and theoretical band strengths have also been determined. The IR spectra provided are expected to guide the possible detection of this species in the solid phase with the JWST. Our results suggest that some weak absorptions tentatively attributed to mixtures of large PAHs in the IR spectra of interstellar ices\footnote{E. Chiar et al. 2021, ApJ, 908, 239}) should have a large contribution of indene and other small aromatic hydrocarbons. Additionally, experiments on energetic processing of indene ices with 5 keV and VUV photons have been performed, to mimic the effect that Cosmic Rays and the secondary UV field, respectively, will have on this species if present on the surface of dust grains in dense clouds. Indene radiolysis and VUV photolysis destruction cross sections have been derived.\footnote{Authors acknowledge support from the Ministerio de Ciencia e Innovacion (MICINN) of Spain under grant PID2020-113084GB-100}

Complex organic species are expected to be formed in a variety of interstellar environments at the surface of ice grains by means of a combination of energetic and nonenergetic processing, e.g., photons, electrons, ions, and atoms. However, to date, many fundamental questions on the physicochemical origin of the observed molecular complexity in space and its link to life on Earth remain unanswered. The recent successful launch, deployment, and commissioning of James Webb Space Telescope (JWST) is a remarkable milestone, marking the onset of a new era for space science, astrophysics, astrochemistry, and astrobiology. The unprecedented combination of JWST and ground-based Atacama Large Millimeter/submillimeter Array (ALMA) observations will map and trace the ice and gas content of the interstellar medium toward a variety of space environments and physicochemical conditions, revolutionizing our understanding of the star formation process. A coordinated effort from the laboratory ice community is now needed to provide state-of-the-art ice spectral analogs that will allow for a correct interpretation of observational ice data. In my talk, I will review the current status of laboratory ice databases and a few emerging techniques that can potentially help address some of the “Grand Challenges” in astrochemistry of the next decade.

Reactions of C atoms and C⁺ cations with NH₃ on water ice were characterized with density function theory using modestly sized water clusters. Both reactions are expected to occur in dense interstellar clouds and in protostellar sources. The neutral C(³P) + NH₃ reaction on ice begins with the formation of triplet CNH₃ via dative bonding involving the 2s² lone pair on nitrogen. Assuming it is not ejected into the gas phase, CNH₃ can subsequently react with one or two H atoms to yield CH₂NH₂ and then CH₃NH₂. The ion-molecule C⁺(²P) + NH₃ reaction on ice begins with charge transfer so that C(³P) reacts with NH₃⁺. The short-lived CNH₃⁺ intermediate, which has a covalent C-N bond, deprotonates to yield the H₂NC radical, which was detected in 2021 toward the dark cloud L483 and other sources. Doublet H₂NC can react with H atoms to yield several different products. The vibrational spectrum of NH₃ on amorphous ice will also be presented.

Ion transport represents a vital process in all modern lifeforms, but how early cells could have accomplished this without the complex proteins used by modern cells has remained a mystery. Here, we investigate thermal reactions in interstellar analog ices of ammonia (NH₃) and acetaldehyde (CH₃CHO) with high-sensitivity and isomer-specific tunable vacuum-ultraviolet photoionization techniques. Nucleophilic addition allows access to 1-aminoethanol (CH₃CH(OH)NH₂) at temperatures as low as 65 K. Isotopic substitution experiments in concert with computational analysis provide mechanistic information on addition and dehydration reactions in the unique environment of interstellar ices. The high sensitivity of photoionization mass spectrometry reveals the formation of additional products such as ethanimine (CH₃CHNH) and the first observations of 1-(1-hydroxyethylamino)ethanol (NH(CH(OH)CH₃)₂) and 1-ethylideneaminoethanol (CH₃CH(OH)NCHCH₃). Low-temperature formation of these molecules indicates that sequential addition and dehydration reactions are feasible in cold interstellar environments and represent an unconventional starting point from which large chelating agents of biorelevant metal ions may have been produced abiotically and with delivery to planets like early earth could enable ion transport in primitive cells.

The photodecomposition of ketene under interstellar conditions and how the resulting photofragments may recombine in the 3-300 K temperature range could play an important role in investigations related to astrochemistry and astrobiology. Using a combination of bulk ice and rare-gas matrix isolation studies coupled to FTIR spectroscopy, the present work aims to understand the VUV photochemistry of CH₂CO in solid phase to mimic the photochemistry of organic species trapped in the icy interstellar grains. We show that the photolysis of CH₂CO depends strongly on the environments where it is trapped. The VUV photolysis of CH₂CO/Ne in dilute phase leads to kinetically stable and instable species such as CO, C₂H₂, CH₄, C₂H₄, C₂H₆, H₂CO, CH₃CHO, HCCO, C₂O, C₃O and C₄O. However, the same experiment carried out in condensed phase shows that the photolysis of CH₂CO ice produces mainly an organic residue which is directly observed at 10 K and remains stable in solid phase at 300 K. The IR spectroscopy analysis suggests that the resulting organic residue could be a polyketone formed at 10 K through the VUV photo-polymerization of ketene.