and

ne emission and the zero-field splitting parameters D and E of the superphane 1 and the [2,](1,2,3,4,5)-cyclophane 2 are investigated. The large number of six and five metbyiene bridges, respectively, leads to a more rigid molecular frame and to a smaller transanular distance as compared to other ~2,2~~oph~~. The experimental results exhibit characteristic features which are due to these unusual properties; they are discussed and compared with ~-empi~ ~ a-electron cakuIations. 1. In&Mm The strength of the n-electron interaction in cyclophanes with identical subunits is determined by the distance as well as by the relative orienta-tion of the two aromatic molecular subunits with respect to each other. It is studied in general by various spectroscopic methods, such as absorp-tion, emission and Raman spectroscopy, and in particular the investigation of the triplet zero-field splitting parameters by magnetic resonance and optically detected magnetic resonance (ODMR)