Synthesis and structure of a hydrogenated zinc hemiporphyrazine.

Palladium-catalyzed hydrogenation of an octahedral zinc trans-ditriflate hemiporphyrazine "HpH2Zn(OTf)2" furnishes a new macrocycle "HpH6Zn(OTf)2". This reaction is fully reversible upon heating in nitrobenzene, and the conversion is easily monitored by changes in color and fluorescence properties. The reversible cycling between these molecules may find future applications in hemiporphyrazine-based catalysts and/or hydrogen storage devices.