title: Intramolecular Hydrogen Bonds in Low-Molecular-Weight Polyethylene Glycol.
abstract: We used static DFT calculations to analyze, in detail, the intramolecular hydrogen bonds formed in low-molecular-weight polyethylene glycol (PEG) with two to five repeat subunits. Both red-shifted O-H⋅⋅⋅O and blue-shifting C-H⋅⋅⋅O hydrogen bonds, which control the structural flexibility of PEG, were detected. To estimate the strength of these hydrogen bonds, the quantum theory of atoms in molecules was used. Car-Parrinello molecular dynamics simulations were used to mimic the structural rearrangements and hydrogen-bond breaking/formation in the PEG molecule at 300 K. The time evolution of the H⋅⋅⋅O bond length and valence angles of the formed hydrogen bonds were fully analyzed. The characteristic hydrogen-bonding patterns of low-molecular-weight PEG were described with an estimation of their lifetime. The theoretical results obtained, in particular the presence of weak C-H⋅⋅⋅O hydrogen bonds, could serve as an explanation of the PEG structural stability in the experimental investigation.
authors: Institute of Chemistry, University of Bialystok, Ciolkowskiego Str. 1K, 15-245, Bialystok, Poland. mari.kozlowska@gmail.com.
authors: Mariana
authors: M
authors: Kozlowska
authors: Institute of Chemistry, University of Bialystok, Ciolkowskiego Str. 1K, 15-245, Bialystok, Poland.|Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC), Friedrich-Alexander-University Erlangen-Nürnberg, Nägelsbachstr. 25, 91052, Erlangen, Germany.
authors: Jakub
authors: J
authors: Goclon
authors: Institute of Chemistry, University of Bialystok, Ciolkowskiego Str. 1K, 15-245, Bialystok, Poland.
authors: Pawel
authors: P
authors: Rodziewicz
keywords: density functional calculations; hydrogen bonds; intramolecular interactions; molecular dynamics; polyethylene glycol