Theoretical prediction of structural, vibrational and NMR parameters of plastic optical fiber (POF) material precursors. Cis and trans perhydro- and perfluoro-2-methylene-4,5-dimethyl-1,3-dioxolanes

• Density functional theory studies on precursors of plastic optical fiber material were performed.
• Hydrogenated and perfluorinated 1,3-dioxolane were studied as models of 2-methylene-4,5-dimethyl-1,3-dioxolane.
• The molecular structure, vibrational frequencies, isotropic nuclear shieldings and indirect spin–spin coupling constants were calculated.
• The combined IR and NMR theoretical calculations suggested a possibility to differentiate between H- and F-containing cis- and trans-isomers.

Density functional theory (DFT) prediction of cis and trans perhydro- and perfluoro-2-methylene-4,5-dimethyl-1,3-dioxolanes structure, supported by vibrational analysis and calculation of multinuclear isotropic nuclear magnetic resonance (NMR) shieldings and indirect spin–spin couplings (SSCCs) was performed. The performance of the used methodology was verified on 1,3-dioxolane selected as model compound. The structures of hydrogenated and fluorinated monomers of POF materials were calculated using B3LYP and BLYP density functionals combined with 6-311++G(3df,2pd) basis set. The BLYP/6-311++G(3df,2pd) level of theory was suggested for vibrational analysis. Gauge independent atomic orbitals (GIAO) calculations were applied to distinguish between cis and trans isomers of the title 1,3-dioxolanes. For obtaining both accurate nuclear shieldings and individual spin–spin coupling constants the BHandH/aug-pcJ-2 level of theory was chosen. The protocol used for the calculations nicely showed remarkable differences in vibrational spectra and NMR parameters of cis and trans isomers of the studied 1,3-dioxolane derivatives before and after fluorination.

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