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Updated: Feb 12, 2026

Microcrystal Electron Diffraction of Small Molecules
Published on: March 15, 2021
[Study on quantitative relationships between electronic structure and toxicities of phenyl-aldehydes and
Xuan Xu1, Yifan Luo, Yuncai Xiang
1Department of Chemistry, South China Normal University, Guangzhou 510631, China.
Abstract:
The quantum chemical indexes of 13 phenyl-aldehydes and 18 nitrogen-containing aromatic molecules were calculated by PM3 method. Two quantitative structure-activity relationships of phenyl-aldehydes and nitrogen-containing aromatic molecules between quantum chemical indexes and toxicitives were obtained as follows: (1) for phenyl-aldehydes: pLD50 = -3.473 - 0.447 ELUMO, which indicated that the toxicities (pLD50) of phenyl-aldehydes would increase when energy of the lowest unoccupied molecular orbital (ELUMO) decrease, while the polarity of C = O group and dipolar moment increase; (2) for nitrogen-containing aromatic molecules: pIGC = 0.936 - 5.24 x 10(-5) E -0.300 DELH, which indicated that toxicities (pIGC) of nitrogen-containing aromatic molecules would increase when molecular energy E and the difference of HOMO and LUMO energy DELH decrease. The molecular energy E decreased mainly because of the enlargement of molecular volume which resulted in the enlargement of logP.
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