Flexible picene thin film field-effect transistors (FETs) have been fabricated with parylene gate dielectric on polyethylene terephthalate substrates. The picene thin film FETs show p-channel output/transfer characteristics and the field-effect mobility $\mu$ reaches $\sim 1{\text{cm}}^2{\text{V}}^{-1}{\text{s}}^{-1}$ in vacuum. The FET shows a clear ${\text{O}}_2$ gas sensing effect and negligible hysteresis in the transfer curves, indicating a possible application of the transistor as ${\text{O}}_2$ selective gas sensor. Furthermore, it has been found that the parylene gate dielectric can eliminate a reduction in on-state drain current caused by continuous bias-voltage application which is observed if a ${\text{SiO}}_2$ gate dielectric is used.

A new cobalt(II) complex bearing a pair of cobalt(III) tris-chelate complexes as metalloligands was prepared. The Co^II ion possesses an ideal trigonal antiprismatic geometry because of the intermolecular hydrogen-bonds between the metalloligands via counter anions. This complex exhibits slow magnetic relaxation under a dc field reminiscent of a single-molecule magnet behavior.

Zero field slow magnetic relaxation was observed in two cobalt( ii ) complexes with 1-D chain hydrogen-bonded structures.