As opposed to the thoroughly studied carbon-bridged calixarenes, [1] heteroatom-bridged [1 n ]metacyclophanes and their derivatives have recently attracted much attention mainly because of novel structure-property relationships originating from the replacement of methylene bridges with heteroatom bridges.[2] On the other hand, only a few reports are known for [1 n ]paracyclophanes, probably as a result of the difficulty in synthesizing them (Scheme 1). [3,4] Aza[1 n ]paracyclophanes can be viewed as macrocyclic oligomers of polyaniline, which is one of the well-known organic conducting polymers. [5] As is apparent from the simple Hückel MO calculations, the HOMOs for linear and cyclic oligoanilines assume different aspects, as exemplified in Scheme 2. As for the linear hexamer, the large MO coefficients are concentrated on the central para-phenylenediamine (PD) moiety. Owing to the localized HOMO character, the ESR studies on the radical cations of linear oligoanilines showed that the spin was confined to the central PD moiety, and therefore, spin delocalization took place only to a small extent.[6] In contrast, the HOMO coefficients of the cyclic hexamer is mainly distributed equally on six nitrogen nuclei. In fact, according to the DFT calculations, the HOMO coefficients of all-N-phenyl-substituted hexaaza[1 6 ]paracyclophane (1') is delocalized over the macrocyclic molecular backbone, and therefore, the DFT-predicted spin density distribution in the corresponding radical cation discerns the delocalized character (Figure 1). In this respect, it is interesting to examine the spin distribution of the radical cation of cyclic oligoanilines in conjunction with the question: to what extent is an unpaired electron delocalized within the polyaniline backbone?However, the preparation of aza[1 n ]paracyclophanes are hitherto unknown, and the elucidation of their electronic properties is in demand from the viewpoint of materials chemistry. This communication reports the synthesis and characterization of electronic structures of all-N-anisyl-substituted hexaaza[1 6 ]paracyclophane (1) and its oxidized species.The title compound (1) was not obtained by the simple single-step coupling reaction from para-halogenated secondary arylamines. In addition, convergent fragment coupling synthesis [1] from the combinations of simple secondary arylamines and aryl halides was also unsatisfactory to us. For example, an equimolar coupling reaction of N,N'-bis(4-

As opposed to the thoroughly studied carbon-bridged calixarenes, [1] heteroatom-bridged [1 n ]metacyclophanes and their derivatives have recently attracted much attention mainly because of novel structure-property relationships originating from the replacement of methylene bridges with heteroatom bridges. [2] On the other hand, only a few reports are known for [1 n ]paracyclophanes, probably as a result of the difficulty in synthesizing them (Scheme 1). [3,4] Aza[1 n ]paracyclophanes can be viewed as macrocyclic oligomers of polyaniline, which is one of the well-known organic conducting polymers. [5] As is apparent from the simple Hückel MO calculations, the HOMOs for linear and cyclic oligoanilines assume different aspects, as exemplified in Scheme 2. As for the linear hexamer, the large MO coefficients are concentrated on the central para-phenylenediamine (PD) moiety. Owing to the localized HOMO character, the ESR studies on the radical cations of linear oligoanilines showed that the spin was confined to the central PD moiety, and therefore, spin delocalization took place only to a small extent. [6] In contrast, the HOMO coefficients of the cyclic hexamer is mainly distributed equally on six nitrogen nuclei. In fact, according to the DFT calculations, the HOMO coefficients of all-N-phenyl-substituted hexaaza[1 6 ]paracyclophane (1') is delocalized over the macrocyclic molecular backbone, and therefore, the DFT-predicted spin density distribution in the corresponding radical cation discerns the delocalized character (Figure 1). In this respect, it is interesting to examine the spin distribution of the radical cation of cyclic oligoanilines in conjunction with the question: to what extent is an unpaired electron delocalized within the polyaniline backbone?However, the preparation of aza[1 n ]paracyclophanes are hitherto unknown, and the elucidation of their electronic properties is in demand from the viewpoint of materials chemistry. This communication reports the synthesis and characterization of electronic structures of all-N-anisyl-substituted hexaaza[1 6 ]paracyclophane (1) and its oxidized species.The title compound (1) was not obtained by the simple single-step coupling reaction from para-halogenated secondary arylamines. In addition, convergent fragment coupling synthesis [1] from the combinations of simple secondary arylamines and aryl halides was also unsatisfactory to us. For example, an equimolar coupling reaction of N,N'-bis(4-Scheme 2. Schematic views of HOMOs of a) linear and b) cyclic hexamers of polyaniline. Scheme 1. Reported heteroatom-bridged [1 n ]paracyclophanes and hexaaza[1 6 ]paracyclophane 1 and 1'.