As aromatic compounds, porphyrins and related macrocycles undergo a wide range of electrophilic substitution reactions, leading to a correspondingly wide range of functionalized derivatives. Less widely appreciated are reactions effecting skeletal rearrangements and alterations to the N4 core of the molecules. Several of these reactions afford exotic macrocycles that cannot be readily accessed by other means. An excellent example of such a reaction is the ring expansion of a corrole to a 6-azahemiporphycene (H2[AHP]) via interaction with a nitrogen atom source. A related example involves the ring expansion of a corrole to a hemiporphycene. Several transition metal derivatives of (aza)hemiporphycenes have been reported, but by and large their electrochemical, optical and photophysical properties remain inadequately explored. The intriguing question as to their suitability as photosensitizers in photodynamic therapy also remains unanswered. Herein we have made an attempt to shed light in these questions, focusing on manganese, palladium and platinum complexes of 6azahemiporphycenes (Chart 1).