2,2′-Bridged biphenyls with 12-membered heterocyclic bridging rings. Part 1. Tetrabenzo[b,d,h,j][1,6]diazacyclododecines

Abstract

Four tetrabenzo[b,d,h,j][1,6]diazacyclododecines and their tetrahydro-derivatives have been prepared. ¹H N.m.r. and u.v. spectroscopy are used to determine the geometry of the tetrabenzodiazadodecines. It is concluded that they have the EE configuration, with dihedral angles in the biphenyl moieties of 55–60° and with angles of twist about the Ar_C–CHN and Ar_N–NCH single bonds of 10–20 and 80–70° respectively. N.m.r. spectra in the presence of chiral lanthanide shift reagents show that at least two of the compounds are chiral.