Microhydration Structures of Protonated Oxazole

dc.contributor.authorChatterjee, Kuntal
dc.contributor.authorDopfer, Otto
dc.date.accessioned2019-08-28T12:28:41Z
dc.date.available2019-08-28T12:28:41Z
dc.date.issued2019-08-22
dc.description.abstractThe 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.eissn1520-5215
dc.identifier.issn1089-5639
dc.identifier.urihttps://depositonce.tu-berlin.de/handle/11303/9923
dc.identifier.urihttp://dx.doi.org/10.14279/depositonce-8933
dc.language.isoenen
dc.relation.ispartof10.14279/depositonce-10571en
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.ddc541 Physikalische Chemiede
dc.subject.otherligandsen
dc.subject.otherstructural changeen
dc.subject.otheraromatic moleculeen
dc.subject.othermicrohydrateden
dc.subject.otherclustersen
dc.titleMicrohydration Structures of Protonated Oxazoleen
dc.typeArticleen
dc.type.versionacceptedVersionen
dcterms.bibliographicCitation.doi10.1021/acs.jpca.9b06587en
dcterms.bibliographicCitation.journaltitleThe Journal of Physical Chemistry Aen
dcterms.bibliographicCitation.originalpublishernameAmerican Chemical Societyen
dcterms.bibliographicCitation.originalpublisherplaceWashington DCen
tub.accessrights.dnbdomain*
tub.affiliationFak. 2 Mathematik und Naturwissenschaften::Inst. Optik und Atomare Physik::FG Lasermolekülspektroskopie und Umweltphysikde
tub.affiliation.facultyFak. 2 Mathematik und Naturwissenschaftende
tub.affiliation.groupFG Lasermolekülspektroskopie und Umweltphysikde
tub.affiliation.instituteInst. Optik und Atomare Physikde
tub.publisher.universityorinstitutionTechnische Universität Berlinen
Files
Original bundle
Now showing 1 - 1 of 1
Loading…
Thumbnail Image
Name:
Chatterjee_Dopfer_2019.pdf
Size:
5.59 MB
Format:
Adobe Portable Document Format
Description:
License bundle
Now showing 1 - 1 of 1
Loading…
Thumbnail Image
Name:
license.txt
Size:
4.9 KB
Format:
Item-specific license agreed upon to submission
Description:
Collections