Magnetic properties of altan-[n]annulenes

Abstract

The altanisation strategy is applied to [n]annulenes to give altan-[n]annulenes.1 In particular, altan-[24]annulene and altan-[30]annulene were examined in this study. These macrocyclic systems show unique optical, electrochemical, and magnetic properties.2 The structure of the studied molecules can be rationalized by means of an annulene-within-an-annulene model. The pseudo-π method for current density calculations was performed. In altan-[24]annulene, both annulene subunits sustain diatropic (aromatic) character in singlet and triplet states. On the other side, in altan[30]annulene the outer ring sustain paratropic (antiaromatic) currents, but the inner ring sustain diatropic currents in the singlet state, but in the triplet state, both subunits sustain diatropic currents. Calculated ef values confirmed more intensive circulations in sixmembered rings than in five-membered rings.