PROCEEDINGS OF THE SECOND INTERNATIONAL CONFERENCE ON "MODERN TRENDS IN ENGINEERING, SCIENCE, MANAGEMENT, AND TECHNOLOGY" (MESMT - 2026)

Citric acid anhydrous (CAA) is a biologically significant compound with
promising antimicrobial potential. This study presents a comprehensive
investigation of its structural, conformational, spectroscopic, electronic, and
molecular docking properties using combined experimental and Density
Functional Theory (DFT) methods at the B3LYP/6-311G(d,p) level. The
optimized geometry shows strong agreement with experimental X-ray diffraction
data. Potential energy surface analysis identifies the most stable conformer at a
dihedral angle of 216°. Vibrational analysis confirms 57 normal modes,
consistent with theoretical expectations. FT-IR, UV–Visible, and NMR studies
exhibit excellent correlation with computed spectra. HOMO–LUMO analysis
reveals an energy gap of 6.518 eV, indicating moderate stability and reactivity.
NBO analysis highlights significant intramolecular charge transfer interactions
with high stabilization energy. Molecular docking against antimicrobial targets
(1W78 and 1W7K) demonstrates favorable binding affinity. These findings
underscore the structural stability and biological relevance of CAA for potential
pharmaceutical and antimicrobial applications.