Molecular Structure of 2-hydroxy-5-methyl-2-nitroazobenzene Isomer: DFT Insight

Abstract

Abstract It is currently thought that azobenzene molecules exist in trans and cis form of molecular structure configuration. Affirmation supporting this perspective has been substantially derived by theoretical results in the isomerization process. However, whether these molecular structures may affect the electronic properties entirely need to be confirmed. In this study, I give my effort to understand the molecular structure properties of trans and cis form of azobenzene molecule from 2-hydroxy-5-methyl-2’-nitroazobenzene (HMNA). Their chemistry phenomena are investigated using density functional theory (DFT) method. According to this study, it show that the molecular size of trans form of HMNA is 9.0 Å and cis form of HMNA is 6.6 Å, have electronic transition of π → π* type driven by azo bond in trans-HMNA whereas C = C bond on the benzene ring offers higher contribution for cis-HMNA and also cis-HMNA shows n → π* type with respect to the non-bonding electrons of oxygen and nitrogen atoms while trans-HMNA form does not show any significance. Therefore, this molecule system as a push-pull molecule system contributes to the chemistry properties and phenomenon for molecular structure, electronic transition and mechanism pathway of trans to cis isomer formation in the ground state.