A Cyclic Porphyrin Tetramer Linked by Azo and Butadiyne Bridges (Eur. J. Org. Chem. 23/2010)

The cover picture shows the tetranickel complex of a rectangular porphyrin array with novel connectivity. Conjugating azo and butadiyne bridges link the opposite sides of the rectangle, and the absorption spectrum demonstrates strong electronic communication between the chromophores. The synthesis and characterisation of this tetramer are described in the article by D. P. Arnold et al. on p. 4381 f. The molecule is set against a background of a sunset on the Great Barrier Reef, emphasising the role of porphyrinoid pigments in solar energy capture.