Microhydration Structures of Protonated Oxazole
dc.contributor.author | Chatterjee, Kuntal | |
dc.contributor.author | Dopfer, Otto | |
dc.date.accessioned | 2019-08-28T12:28:41Z | |
dc.date.available | 2019-08-28T12:28:41Z | |
dc.date.issued | 2019-08-22 | |
dc.description.abstract | The initial microhydration structures of the protonated pharmaceutical building block oxazole (Ox), H+Ox-Wn≤4, are determined by infrared photodissociation (IRPD) spectroscopy combined with quantum chemical dispersion-corrected density functional theory calculations (B3LYP-D3/aug-cc-pVTZ). Protonation of Ox, achieved by chemical ionization in a H2-containing plasma, occurs at the most basic N atom. The analysis of systematic shifts of the NH and OH stretch vibrations as a function of the cluster size provides a clear picture for the preferred cluster growth in H+Ox-Wn. For n = 1–3, the IRPD spectra are dominated by a single isomer, and microhydration of H+Ox with hydrophilic protic W ligands occurs by attachment of a hydrogen-bonded (H-bonded) Wn solvent cluster to the acidic NH group via an NH···O H-bond. Such H-bonded networks are stabilized by strong cooperativity effects. This is in contrast to previously studied hydrophobic ligands, which prefer interior ion solvation. The strength of the NH···O ionic H-bond increases with the degree of hydration because of the increasing proton affinity (PA) of the Wn cluster. At n = 4, proton-transferred structures of the type Ox-H+Wn become energetically competitive with H+Ox-Wn structures, because differences in solvation energies can compensate for the differences in the PAs, and barrierless proton transfer from H+Ox to the Wn solvent subcluster becomes feasible. Indeed, the IRPD spectrum of the n = 4 cluster is more complex suggesting the presence of more than one isomer, although it lacks unequivocal evidence for the predicted intracluster proton transfer. | en |
dc.identifier.eissn | 1520-5215 | |
dc.identifier.issn | 1089-5639 | |
dc.identifier.uri | https://depositonce.tu-berlin.de/handle/11303/9923 | |
dc.identifier.uri | http://dx.doi.org/10.14279/depositonce-8933 | |
dc.language.iso | en | en |
dc.relation.ispartof | 10.14279/depositonce-10571 | en |
dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
dc.subject.ddc | 541 Physikalische Chemie | de |
dc.subject.other | ligands | en |
dc.subject.other | structural change | en |
dc.subject.other | aromatic molecule | en |
dc.subject.other | microhydrated | en |
dc.subject.other | clusters | en |
dc.title | Microhydration Structures of Protonated Oxazole | en |
dc.type | Article | en |
dc.type.version | acceptedVersion | en |
dcterms.bibliographicCitation.doi | 10.1021/acs.jpca.9b06587 | en |
dcterms.bibliographicCitation.journaltitle | The Journal of Physical Chemistry A | en |
dcterms.bibliographicCitation.originalpublishername | American Chemical Society | en |
dcterms.bibliographicCitation.originalpublisherplace | Washington DC | en |
tub.accessrights.dnb | domain | * |
tub.affiliation | Fak. 2 Mathematik und Naturwissenschaften::Inst. Optik und Atomare Physik::FG Lasermolekülspektroskopie und Umweltphysik | de |
tub.affiliation.faculty | Fak. 2 Mathematik und Naturwissenschaften | de |
tub.affiliation.group | FG Lasermolekülspektroskopie und Umweltphysik | de |
tub.affiliation.institute | Inst. Optik und Atomare Physik | de |
tub.publisher.universityorinstitution | Technische Universität Berlin | en |