Understanding molecular properties of halogenated cyclohexane – A DFT study

In this work, using density functional theory (DFT) method, halogenated cyclohexane isomers have been studied in order to understand the influence of halogens (F, Cl, Br) on the molecular properties. The substitution of halogens has induced significant changes in the geometrical parameters of cyclohexane ring. Relative energy values suggest that the isomer epsilon in HFCH/HClCH, and isomer theta in HBrCH are the most stable structures. The 1,3 diaxial interactions are present in all the isomers irrespective of the halogen substituents. Fluorination of cyclohexane enhances HOMO–LUMO gap and chemical hardness, which subsequently indicates low reactiveness of the HFCH isomers. The principle of maximum hardness (MHP) and the minimum electrophilicity fails to predict stability order of isomers.