TY - JOUR ID - 47803 TI - Theoretical Study of M2X4 (M=C, X=H, F, and Cl) Structures by using HOMO, LUMO, NBO, and NMR analysis JO - International Journal of New Chemistry JA - IJNC LA - en SN - 2645-7237 AU - mahmoudzadeh, Golrokh AD - Chemistry Department, North Tehran Branch, Azad University, Tehran, Iran. Y1 - 2021 PY - 2021 VL - 8 IS - 2 SP - 198 EP - 221 KW - : MP2 method KW - NBO analysis KW - NMR shielding KW - HOMO-LUMO DO - 10.22034/ijnc.2020.122648.1100 N2 - All calculations were performed within the MP2 / 6-311 G (d, p) method to evaluate the effects of substituent groups which affect the structural stability and molecular energy. A natural bond orbital (NBO) analysis and isotopic, and anisotropic NMR chemistry, were used also for a better understanding of the C2X4 electronic structure and its derivatives. The NBO analysis shows that the occupancy of lone pair electrons of halogen atoms in all compounds decreases with increasing p character of the lone pair of halogen atoms. Furthermore, NBO analysis demonstrated the effects of donates substituent groups including (CH3, NH2, and OH) that donates some of its electron density into a π system via resonance or inductive effects, thus making the π system more nucleophilic on electron density. The obtained values from NMR tensors parameters shows electronegativity in excellent agreement with the expected chemical shielding values. Therefore, we suggest that is correlations between donates substituent groups with electronegativity along with the total stability energy of the studied molecules. The energies gap of frontier molecular orbital (ɛLUMO- ɛHOMO) is recorded in order to find the suitability correlation between this energy with chemical hardness (η) of the studied molecules. UR - https://www.ijnc.ir/article_47803.html L1 - https://www.ijnc.ir/article_47803_05847e9745d06430feb095ab45790ae0.pdf ER -