AIP Advances (Nov 2021)

Helium nanodroplet infrared spectroscopy of oxazole-(water)n (n = 1,2) clusters

  • Tarun Kumar Roy,
  • Kuntal Chatterjee,
  • Jai Khatri,
  • Gerhard Schwaab,
  • Martina Havenith

DOI
https://doi.org/10.1063/5.0066419
Journal volume & issue
Vol. 11, no. 11
pp. 115112 – 115112-9

Abstract

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The mass-selective infrared (IR) spectra of oxazole-(D2O)n≤2 complexes embedded in helium droplets are recorded in the spectral range of 2565–2800 cm−1. The experimental IR spectra are assigned by comparing with quantum chemical calculations at the MP2/6-311++G(d,p) level of theory. Here, we show that in the case of the 1:1 oxazole-D2O dimer, the water molecule binds to the N atom of the heterocyclic ring via a N⋯DO hydrogen bond (H-bond). However, in the oxazole-(D2O)2 trimer, the water dimer forms N⋯DO and CH⋯O H-bonds with the N atom and adjacent CH group, respectively, leading to the formation of a seven-membered ring. We compare these results with those of our recently reported isoxazole-(water)n≤2 complexes to demonstrate differences in the hydration motif of these two structural isomers.