Extremely Long C-C Bond in (-)-trans-1,2-Di-tert-butyl-1,2-diphenyl- and 1,1-Di-tert-butyl-2,2-diphenyl-3,8-dichlorocyclobuta[b]naphthalenes.
The sterically bulky t-Bu-substituted derivatives of 1,1,2,2-tetraphenyl-3,8-dichlorobuta[b]naphthalene (5), trans-1,2-tert-butyl-1,2-diphenyl- (8) and 1,1-di-tert-butyl-2,2-diphenyl-3,8-dichlorocyclobuta[b]naphthalene (12), were prepared. X-ray analysis of 8 and 12 at 150 K showed that C-C bonds of 8 and 12 are 1.686 and 1.729 Å, respectively. The latter bond length is longer than that of 1.720 Å in 5 and is the longest one reliably determined to date.
Toda
Fumio
F
Department of Applied Chemistry, Faculty of Engineering, Ehime University, Matsuyama 790-8577, Japan, and Department of Chemistry, Faculty of Science, Osaka City University, Sugimoto-cho, Sumiyoshi-ku, Osaka 950, Japan.
Tanaka
Koichi
K
Watanabe
Masaki
M
Tamura
Kenichi
K
Miyahara
Ikuko
I
Nakai
Tadashi
T
Hirotsu
Ken
K