Electrical and optical properties of copper and nickel molecular materials with tetrabenzo [b,f,j,n] [1,5,9,13] tetraazacyclohexadecine thin films grown by the vacuum thermal evaporation technique.

Semiconducting molecular-material thin-films of tetrabenzo (b,f,j,n) [1,5,9,13] tetraazacyclohexadecine copper(II) and nickel(II) bisanthraflavates have been prepared by using vacuum thermal evaporation on Corning glass substrates and crystalline silicon wafers. The films thus obtained were characterized by infrared spectroscopy (FTIR), atomic force microscopy (AFM), ultraviolet-visible (UV-vis) spectroscopy and ellipsometry. IR spectroscopy showed that the molecular-material thin-films exhibit the same intra-molecular bonds as the original compounds, which suggests that the thermal evaporation process does not significantly alter their bonds. The optical band-gap values calculated from the absorption coefficient may be related to non-direct electronic interband transitions. The effect of temperature on conductivity was also measured in these samples. It was found that the temperature-dependent electric current is always higher for the nickel-based material and suggests a semiconductor-like behavior with conductivities in the order of 10(-8)Omega(-1)cm(-1).

[Leprosy: a rare imported disease]. / Une maladie d'importation rare: la lèpre.

Although rare in occidental countries, leprosy is an endemic disease throughout the world. Physicians may encounter imported cases and thus need to be aware of this diagnosis. We here report a 41-year-old male patient from French West Indies who presented with nonspecific extensive skin lesions and a peripheral neuropathy. Skin biopsy examination led to the diagnosis of borderline lepromatous leprosy.