N-methyl-substituted aza[1n]metacyclophane:: Preparation, structure, and properties

A series of aza[1(n),]metacyclophanes (n = 3-8), which correspond to the cyclic oligomers of poly(m-aniline), are obtained in one step by a Pd(0)-catalyzed amination reaction of 3-bromo-N-methylaniline. The most stable conformations of the cyclic trimer and tetramer are determined by density functional calculations. The theoretical results show that these new macrocyclic compounds can be regarded as precursors for cyclophane-based high-spin molecules. Moreover, we describe their spectroscopic and electrochemical properties in connection with the ring size of these cyclic oligomers.