
TY  - JOUR
A1  - Collins, MJ 
A1  - Sternhell, S 
A1  - Tansey, CW 
T1  - N.M.R.-Studies of Bond Order in Azulene, Biphenylene and 1,6-Methano[10]annulene
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1990
VL  - 43
IS  - 9
SP  - 1541
EP  - 1546
KW  - 
UR  - https://doi.org/10.1071/CH9901541 
N2  - The 4J(H-C-C-Me) coupling constants of methyl-substituted derivatives, probes of bond order, have been used to examine the ground-state &#960;- electron distributions in azulene (1), biphenylene (2) and 1,6- methano [10] annulene (3). The experimental data obtained are in good agreement with theoretical predictions for biphenylene (2) and provide some evidence for &#960;-electron disproportionation towards the five-membered ring in azulene (1). The bond orders in 1,6-methano [10] annulene (3) obtained in this work are at variance with those predicted on the grounds of bond lengths. 
ER  -

