Abstract MP2 and DFT calculations have been carried out for [n] circulenes for n= 3 to 20 in order to predict the strain energy and topology of these cyclically condensed aromatic systems. To synthesise [4] circulene (2), 1, 5, 7, 8-tetrakis (bromomethyl) biphenylene (14) was prepared from the corresponding tetramethyl derivative (8) and subjected to various dehalogenation reactions; all attempts to obtain [2.2] biphenylenophane (7) as a precursor ...
