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We investigated electrical properties of titanyl-phthalocyanine ͑TiOPc͒ films under ultrahigh vacuum ͑UHV͒ conditions to avoid the influence of gas adsorption. The field-effect measurement revealed that TiOPc films exhibited an n-type semiconducting behavior in UHV. The electron mobility at room temperature was 9ϫ10 Ϫ6 cm 2 V Ϫ1 s Ϫ1 with activation energy of 0.20 eV. The conductivity and carrier density were 9ϫ10 Ϫ8 S cm Ϫ1 and 6ϫ10 16 cm Ϫ3 , respectively. A clear conversion from n-type to p-type behavior was observed when the film was exposed to oxygen. Strict control of atmosphere made it possible to obtain a quasi-intrinsic state where both p-and n-type conductions appeared simultaneously.

We studied the electronic structure of cobalt-phthalocyanine (CoPc) molecules on Au(111) and Cu(100) surfaces by scanning tunneling microscopy and spectroscopy at 5 K. In the differential conductance (dI=dV) spectra, there were some peaks related to the highest occupied molecular orbital (HOMO), the lowest unoccupied MO (LUMO) and the d-orbitals of the Co atom. CoPc molecules on the Cu(100) surface had new electronic states between the peaks related to HOMO and LUMO, while those on the Au(111) surface did not show additional peaks. A dI=dV image indicated that the new states were generated by the hybridization between the LUMO of molecules and the electronic states of the Cu(100) surface.

Aculeacin A, a new antifungal antibiotic was isolated from the mycelial cake of Aspergillus aculeatus M-4214. The antibiotic is a white amorphous powder soluble in lower alcohols and hardly soluble in other organic solvents or water. Aculeacin A gave palmitic acid and five ninhydrin-positive products including threonine, hydroxyproline upon acid hydrolysis. The antibiotic showed a potent activity against molds and yeasts, but exhibited no antibacterial activity.