TITLE:
Investigation of the Stability of Oxadiasole and Their Analogs Using Quantum Mechanics Computation
AUTHORS:
Masoud Karimi
KEYWORDS:
Oxadiazole, DFT, Ab Initio, NMR
JOURNAL NAME:
Computational Chemistry,
Vol.4 No.1,
January
13,
2016
ABSTRACT: This study aimed at investigating factors affecting the stability as well as structural properties of
different Oxadiasole and Thiadiasole isomers based on theoretical level B3LYP/6-311+G**, Nuclear
Magnetic Resonance (NMR), and Nucleus-independent Chemical Shift (NICS). Qualitative relationships
between relative stabilities of 1,2,3-Oxadiazole, 1,2,4-Oxadiazole, 1,2,5-Oxadiazole and
1,3,4-Oxadiazole were obtained. Aromatic stabilization energy (ASE), aromatic ring current (NICS),
HUMO-LUMO gaps, electro-negativity (X), hardness (η), softness (S), electro-philicity (ω) and structural
parameters were also calculated in the same theoretical level. The results show that 1,3,4-Oxadiazole is more stable than 1,2,3-Oxadiazole, 1,2,4-Oxadiazole and 1,2,5-Oxadiazole. Unlike the
trends observed in Oxadiazoles, 1,2,5-Thiadiazole isomer is more stable than other corresponding
Isomers.