Cis-trans isomerization of [9]-annulenanion (1) and its 2-fluoro-, 2-chloro- and 2-bromo-derivatives (2, 3 and 4,respectively) were investigated at the HF/6-31G* and B3LYP/6-311++G** levels of theory. Cis,cis,cis,cis structures appear more stable than their corresponding cis,cis,cis,trans-isomers. The relative height of energy barriers for cis-trans isomerization is: 2cis > 1cis > 3cis> 4cis. This trend for the reverse trans-cis isomerization follows the electronegativity of the substituent at C-2 (2trans > 3trans > 4trans > 1trans).
Abstract：Cis-trans isomerization of [9]-annulenanion (1) and its 2-fluoro-, 2-chloro- and 2-bromo-derivatives (2, 3 and 4,respectively) were investigated at the HF/6-31G* and B3LYP/6-311++G** levels of theory. Cis,cis,cis,cis structures appear more stable than their corresponding cis,cis,cis,trans-isomers. The relative height of energy barriers for cis-trans isomerization is: 2cis > 1cis > 3cis> 4cis. This trend for the reverse trans-cis isomerization follows the electronegativity of the substituent at C-2 (2trans > 3trans > 4trans > 1trans).
AHMADREZA Bekhradnia;SATTAR Arshadi. Theoretical Study of Halogen Effect in Isomerization of 2-Halo-[9]-annulen Anion at the DFT Level [J]. , 2011, 30(6): 906-912.
AHMADREZA Bekhradnia; SATTAR Arshadi. Theoretical Study of Halogen Effect in Isomerization of 2-Halo-[9]-annulen Anion at the DFT Level . , 2011, 30(6): 906-912.
2011, Vol. 30 
