1654-55-3Relevant academic research and scientific papers
N.M.R. Studies of Bond Order in Azulene, Biphenylene 1,6-Methanoannulene
Collins, Michael J.,Sternhell, Sever,Tansey, Charles W.
, p. 1541 - 1546 (2007/10/02)
The 4J coupling constants of methyl-substituted derivatives, probes of bond order, have been used to examine the ground-state ?-electron distributions in azulene (1), biphenylene (2) and 1,6-methanoannulene (3).The experimental data obtained are in good agreement with theoretical predictions for biphenylene (2) and provide some evidence for ?-electron disproportionation towards the five-membered ring in azulane (1).The bond orders in 1,6-methanoannulene (3) obtained in this work are at variance with those predicted on the grounds of bond lenghts.
