Bond orders in 1,5-benzodiazepinium cations compared to those in biphenylenes. Another example of bonds of low bond order which isolated π-electron systems.

Abstract

The bonds which link separate stablishing π-electron systems in 1,5-benzodiazepinium cations are shown from X-ray analysis and MNDO calculations to be of very low bond order, like the bridging bonds in biphenylenes, thereby inhibiting destabilising interaction between the π-electron systems.