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Molecular dynamics of 1, 3-dioxolane

1, 3-Dioxolane is a five membered ring with oxygen atoms at positions 1 and 3. It is flexible, having two low frequency modes at 300 and 134 cm-1 in Raman spectrum of the crystal. In free molecule, there are multiple pseudorotational transitions occurring in place of the lowest frequency mode, and the barrier to pseudorotation is estimated to be less than 50 cm-1. This small molecule is important for possible applications in design of biomaterials, since it polymerizes when mixed with water. We undertook Raman study of 1, 3-dioxolane in Argon matrix and in polycrystalline phases, and found indications of more than one conformer in matrix isolated species. Multiple liquid bands were resolved in Raman spectra of Argon matrix, especially the strongest band at 939 cm-1 and a shoulder at 958 cm-1 splits into three bands at 967, 944 and 920 cm-1. To understand possible conformations of 1, 3-dioxolane, a molecular dynamics simulation was performed for liquid and a matrix isolated species. Gaussian03 was used for calculating vibrations and bent conformation seems to be the one at the minimum of the potential energy surface. The modes observed at 726 and 675 cm-1 are attributed to CH2 twisting modes of the bent conformation, while the third band at 705 cm-1 is assigned to the second conformer.

dioxolane; molecular dynamics; DLPOLY; Raman; matrix isolation

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