First Principles Density Functional Theory Investigation on the Structural, Energetic and Electronic Properties of 6–Bromo–4–Oxo–4H–Chromene–3–Carbaldehyde

In this paper, we report the first principles Density Functional Theory (DFT) calculation to study the structural, energetic, and electronics properties of the 6–Bromo–4–Oxo–4H–Chromene–3–Carbaldehyde, C₁₀H₅BrO₃ molecular framework. Geometry optimization technique was carried out to find the local energy minimum of the title compound using four hybrid DFT functionals with the basis set of 6–311++G**. The optimized molecular structure of C₁₀H₅BrO₃ cluster was then used to determine the HOMO–LUMO gaps, Molecular Electrostatic Potential (MEP), Mulliken atomic charges, and others. Using the four hybrid DFT techniques, the optimized geometries of C₁₀H₅BrO₃ molecular cluster is close to that of measurement data. Our calculation results also show that the total energies obtained are close to each other with the four hybrid DFT procedures. The diagram of electrostatic potential surface show that the regions of negative electrostatic potential around the oxygen atoms, O₁ and O₂. Using the scheme of Mulliken Population Analysis (MPA), the distributions of atomic charges follow the same arguments for the B3LYP/6–311++G**, B3PW91/6–311++G**, M06/6–311++G**, and PBE1PBE/6–311++G** simulation approaches. For example, the atom of C₅ has the highest positively charge, whereas the highest negatively charge was found in the C₄ atom. For Br atom, the atomic charge values obtained are –0.158, –0.222, –0.277, and –0.224, respectively for the B3LYP/6–311++G**, B3PW91/6–311++G**, M06/6–311++G**, and PBE1PBE/6–311++G** computational methods.