Journal ArticleDOI
Microhydrated aromatic cluster cations: Binding motifs of 4-aminobenzonitrile-(H2O)n cluster cations with n ≤ 4
TLDR
The potential of the ABN(+)-H2O dimer is characterized in detail and supports the cluster growth derived from the IRPD spectra, and the formation of a solvent network stabilized by strong cooperative effects is favored over interior ion hydration which is destabilized by noncooperative effects.Abstract:
Infrared photodissociation (IRPD) spectra of mass-selected 4-aminobenzonitrile-(water)n cluster cations, ABN+-(H2O)n with n ≤ 4, recorded in the N–H and O–H stretch ranges are analyzed by quantum chemical calculations at the M06-2X/aug-cc-pVTZ level to determine the evolution of the initial microhydration process of this bifunctional aromatic cation in its ground electronic state. IRPD spectra of cold clusters tagged with Ar and N2 display higher resolution and allow for a clear-cut structural assignment. The clusters are generated in an electron impact source, which generates predominantly the most stable isomers. The IRPD spectra are assigned to single isomers for n = 1–3. The preferred cluster growth begins with sequential hydration of the two acidic NH protons of the amino group (n = 1–2), which is followed by attachment of secondary H2O ligands hydrogen-bonded to the first-shell ligands (n = 3–4). These symmetric and branched structures are more stable than those with a cyclic H-bonded solvent network. Moreover, in the size range n ≤ 4 the formation of a solvent network stabilized by strong cooperative effects is favored over interior ion hydration which is destabilized by noncooperative effects. The potential of the ABN+-H2O dimer is characterized in detail and supports the cluster growth derived from the IRPD spectra. Although the N–H bonds are destabilized by stepwise microhydration, which is accompanied by increasing charge transfer from ABN+ to the solvent cluster, no proton transfer to the solvent is observed for n ≤ 4.read more
Citations
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Vacuum Ultraviolet (VUV) photoionization of small waterclusters
TL;DR: In this article, the appearance energies of a series of protonated water clusters are determined from the photoionization threshold for clusters composed of up to 79 molecules, representing an upper limit of the adiabatic ionization energy of the corresponding parent neutral water cluster in the supersonic molecular beam.
Journal ArticleDOI
Probing Solvation Dynamics around Aromatic and Biological Molecules at the Single-Molecular Level
Otto Dopfer,Masaaki Fujii +1 more
TL;DR: This review describes the development and application of a new experimental approach, namely, picosecond time-resolved pump-probe infrared spectroscopy of size- and isomer-selected aromatic clusters, in which for the first time the dynamics of a single individual solvent molecule can be followed in real time.
Journal ArticleDOI
Microsolvation of the pyrrole cation (Py+) with nonpolar and polar ligands: infrared spectra of Py+-Ln with L = Ar, N2, and H2O (n ≤ 3).
TL;DR: The initial microsolvation process of the heterocyclic aromatic pyrrole cation in its 2A2 ground electronic state is characterized by infrared photodissociation (IRPD) spectroscopy of cold mass-selected Py+-Ln clusters in a molecular beam and dispersion-corrected density functional theory calculations at the B3LYP-D3/aug-cc-pVTZ level.
Journal ArticleDOI
IR spectrum of the protonated neurotransmitter 2-phenylethylamine: dispersion and anharmonicity of the NH3+–π interaction
Aude Bouchet,Markus Schütz,Barbara Chiavarino,Maria Elisa Crestoni,Simonetta Fornarini,Otto Dopfer +5 more
TL;DR: The dispersion-corrected density functional theory calculations reveal the important effects of dispersion on the cation-π interaction and the large vibrational anharmonicity of the NH3(+) group involved in the NH(+)-π hydrogen bond.
Journal ArticleDOI
Stepwise microhydration of aromatic amide cations: formation of water solvation network revealed by infrared spectra of formanilide(+)-(H2O)(n) clusters (n ≤ 5).
TL;DR: Infrared photodissociation spectra of size-selected clusters of the formanilide cation, FA(+)-(H2O)n (n = 1-5), are analyzed by density functional theory calculations at the ωB97X-D/aug-cc-pVTZ level to determine the sequential microhydration of this prototypical aromatic amid cation.
References
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