were completely separated into enantiomers at least on one Although one of the reasons for the continuing interest') in the preparation of novel cyclophane systems rests on the stereochemical properties of these bridged aromatics2-4), their utilization as chiral reagents is conspicuously lacking5). This is surprising, since -compared to many classical base derivative 11, the p-nitrophenylhydrazone 12 as well as the methylamino derivative 14, the nitroso compound 16, and the phenanthrenophane 19 are described here for the first time (see Experimental); we furthermore present a new C2.21paracyc10phane (3). (0 VCH Vcrlagsgcscflschaft mbH, D

Two routes for preparing functionalized [2.2](1,4)phenanthrenoparacyclophanes are described: either the parent system 2 is subjected to electrophilic substitution (bromination, Friedel-Crafts acylation, Rieche formylation: preparation of 5, 6, 7, 11 and 12) or the desired substituents are incorporated in the early stages of the synthesis by the preparation of the corresponding functionalized styryl paracyclophanes and their photocyclization to the respective phenanthrenocyclophanes. By these specific routes various bro-

The charge‐transfer (CT) spectra of the π‐complexes formed by several π‐acceptors with some polynuclear[2.2]paracyclophanes have been measured. Comparison of these CT complexes with those of model compounds supports the existence of the transannular electronic interactions in the paracyclophane nucleus. The infrared spectra of a number of CT complexes reveal the increase of the electron density on the π‐acceptor molecule in the CT complexes. Some crystalline CT complexes were prepared and analysed.

ChemInform Abstract Optical resolution of 22 (2.2)paracyclophanes such as (I) and (II) is examined by HPLC using tris-3,5-dimethylphenylcarbamates of cellulose and amylose as chiral stationary phases. Some of the cyclophanes are new, and their syntheses are described.

Due to the cyclophane structure the energies of the lowest triplet state, phosphorescence lifetimes and phosphorescence/fluorescence quantum yield ratios of [2,2](l,4)naphthalenoparacyclophane (2) and [2,2](1.4)chrysenoparacyclophane (4) differ markedly from the data of 1,4-dimethyl naphthalene and chrysene respectively. By ground state complexation of 2 and 4 with silver Perchlorate the transannular interaction in the cyclophanes is reduced. In contrast to naphthalene. 2 does not effectively quench the benzophenone phosphorescence in benzophenone/ 2 mixed crystals at 77 K. It is shown, however, that this cannot be regarded as a specific property of 2 but rather as an example of the more general phenomenon that steric or stereoelectronic factors can play a considerable role in intermolecular triplet-triplet energy transfer.