The Loca NBO Analysis: The Core Value Of Biogen

The band gap value of the DBAP molecule was calculated as 5.60 eV, which indicates that the DBAP molecule has stable molecular structure and the value is comparable with the band gap energy value of the reported bio-active molecules [16]. The higher hardness and lower softness value indicates the stability of the DBAP molecule. The obtained lower chemical potential and electrophilicity index values are comparable with the potential bioactive molecules [14, 16]. DOS spectrum was also simulated by convoluting the molecular orbitals with Gaussian curves of unit height. These results further validated the FMOs analysis. The green and red lines in the DOS spectrum represent the occupied and virtual orbitals, respectively. The simulated DOS spectrum is shown in Fig. 7b.
3.6 Local reactivity descriptors analysis The electron density based local reactivity descriptors are useful in predicting the reactive sites of the DBAP molecule, which is an important task in designing and developing a pharmaceutical compound. In this work, the
The intramolecular hydrogen bonding C3-H10...O13 is formed by the orbital overlap between the LP of O13 and antibonding C3-H10 orbital which results in ICT and stabilization of the DBAP molecule. The ED in the carbonyl C12=O13 antibonding orbitals σ * and π* (0.0340e, 0.3325e) are significantly higher compared to the C28=O29 antibonding orbitals σ * and π* (0.0315e, 0.2351e). The intramolecular hydrogen bond formation is responsible for this increase in electron population of C=O antibonding orbital and leads to the C12=O13 bond elongation which is responsible for the bond weakening and associated downshift of stretching frequency as discussed in the vibrational analysis. This mechanism plays an important role in the biological activity of the DBAP molecule