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Structures, IR, NMR Spectra and Thermodynamics Properties of Halogenated Compounds X‐1‐ZB 11 H 10 (ZO, S, Se; XF, Cl, Br): A DFT Study
Author(s) -
Li Ping
Publication year - 2010
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201090229
Subject(s) - chemistry , halogen , chemical shift , chlorine , nmr spectra database , electrophile , carborane , chlorine atom , computational chemistry , chemical stability , halide , atom (system on chip) , crystallography , spectral line , stereochemistry , inorganic chemistry , medicinal chemistry , organic chemistry , alkyl , physics , astronomy , computer science , catalysis , embedded system
The halogenated compounds of twelve‐vertex closo‐1‐ZB 11 H 11 (Z=O, S, Se; X=F, Cl, Br) have unusual stability. The structures of halogenated isomers obtained by DFT method indicate that the halogen atoms are more likely to attack the meta vertexes. The chemical thermodynamic properties show that the halogenations are spontaneous and exothermic. The result that both the optimized and experimental cages of closo‐thiaborane have not changed after chlorination indicates that the substitution of a chlorine atom for a hydrogen atom of closo‐thiaborane happens at outer of the cage. The calculated electronic structures show that the three‐dimensioned aromaticity of cage would like positive chlorine atoms to attack. The halogenations by elemental halogen in the presence of metal halides were proved to belong to the electrophilic substitutions and the mechanism was discussed in details. The suggested transition state interpreted the experiments. The thermal rearrangement which was supposed early according to experiments was verified by the thermodynamic properties of chlorination theoretically. The IR and 11 B/ 1 H NMR isotropic chemical shifts were calculated and compared with the experimental data to reconfirm the structures of chlorinated closo‐thiaborane. Furthermore, the predictions on the halogenated closo‐oxaborane and closo‐selenaborane are significant for the syntheses.