Shigeru Sasaki, Yoshihiro Tanabe, Masaaki Yoshifuji
1999
Citations
0
Influential Citations
10
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Sterically hindered 1,4-bis(dimesitylphosphino)-2,3,5,6-tetrafluorobenzene (1) was synthesized by the aromatic nucleophilic substitution of lithium dimesitylphosphide with hexafluorobenzene. Two phosphorus atoms of 1 were oxidized and methylated to give the corresponding bis(phosphoryl)benzene 2 and bis(phosphonio)benzene 32+·2TfO− (TfO− = trifluoromethanesulfonyl), respectively. On the other hand, reaction of 1 with butyllithium and phenyllithium gave more crowded 2,5-dibutyl-1,4-bis(dimesitylphosphino)-3,6-difluorobenzene (4) and 1,4-bis(dimesitylphosphino)-2,5-difluoro-3,6-diphenylbenzene (5), respectively. Structures of 1, 2, 32+·2TfO−, 4, and 5 were confirmed by conventional spectroscopic methods; particularly 19F NMR spectroscopy reflected their crowded structures. Molecular structures of 1, 2, and 32+·2TfO−, were further investigated by X-ray crystallography, where unusually large bond angles around phosphorus atoms were observed. Electrochemical measurements were carried out to investigate redox p...