Spectroscopic and structural investigations of 4-bromomethyl-5-methyl-1,3-dioxol-2-one and 4,5-bis(bromomethyl)-1,3-dioxol-2-one by quantum chemical simulations – A comparative study

The FTIR and FT-Raman spectra of 4-bromomethyl-5-methyl-1,3-dioxol-2-one and 4,5-bis(bromomethyl)-1,3-dioxol-2-one have been recorded in the regions 4000–400 and 4000–100 cm−1, respectively. The geometry of the compounds are optimised with B3LYP method using 6-311++G∗∗ and cc-pVTZ basis sets to characterise all the structural parameters. The optimised structural parameters of the most stable geometry are used in the vibrational frequency calculations. The total electron density and molecular electrostatic potential surfaces of the molecules are constructed by NBO analysis using B3LYP/6-311++G∗∗ method to display the electrostatic potential (electron + nuclei) distribution, molecular shape, size, dipole moments and the reactive centres of the molecules. The energy gap between HOMO and LUMO is measured. The influences of methyl and bromomethyl groups on the skeletal vibrations have been investigated. The global and local reactivity descriptors are also determined to provide the informations on the electrophilic, nucleophilic and free radical prone reactive sites of the molecules.