Heavy group 13 element complexes of N2O2- and N2O4-type dipyrrins exhibited efficient luminescent properties and cation recognition ability.

Stokes radius (dynamic ionic radius) of the alkali metal ions versus the ionic radius (Rion) at 303 K. The dotted line is a guide for the 1 : 1 relation.

Recently low-power, small gas sensors have been strongly demanded to realize "super smart society." In particular, ammonia: NH 3 sensors are expected to be key devices for breath diagnosis. However, it is difficult for NH 3 sensors to obtain high selectivity against hydrogen: H 2 , since conventional metal-oxide gas sensors respond to any reducing gases. In this study, Co-porphyrin functionalized graphene sensors were fabricated, and selective NH 3 sensing was realized by the selective metal-ligand bond of Co with NH 3 . The sensor successfully detected sub-ppm NH 3 , while it showed no response to high concentration H 2 . Furthermore, we investigated the effect of humidity on the Co-porphyrin functionalized graphene NH 3 sensor. We demonstrated the detection of low concentration NH 3 even under rapid humidity changes. We considered that the key sensing mechanism of our sensor is charge transfer to graphene by the electronic structure change of Co-porphyrin-graphene complexes due to NH 3 adsorption on Co-porphyrin.

π-Conjugated porphyrin-containing hollow structures with defined axis-length were successfully synthesized by a two-step template method, i.e., template-assisted cyclization and oligomerization.

We successfully synthesized a hetero face-to-face porphyrin array composed of ZnTPP and RuTPP(DABCO) (TPP: 5, 10, 15, 20-tetraphenylporphyrin, DABCO: 1,4-diazabi-cyclo[2.2.2]octane) in 2:1 molar ratio. A cyclic Zn porphyrin dimer (ZnCP) was also used as the host molecule for the Ru porphyrin. In the latter, the Ru-DABCO bonding in RuTPP(DABCO) was stabilized by the host-guest complexation. Reaction progress kinetic analysis of the ligand substitution reaction of RuTPP(DABCO) and that in ZnCP revealed the stabilization mechanism of the Ru-DABCO bonding. Photoinduced electron transfer (PET) from the Zn porphyrin to the Ru porphyrin was observed in the porphyrin array. The host-guest stabilization of unstable complex for construction of a donor-acceptor-donor structure is expected to be a new method for an artificial photosynthesis.