The Cu(II) and Ag(I) complexes, [Cu(phendio) 3 ](ClO 4 ) 2 ·4H 2 O and [Ag(phendio) 2 ]ClO 4 (phendio = 1,10-phenanthroline-5,6-dione), are prepared in good yield by reacting phendio with the appropriate metal perchlorate salt. The X-ray crystal structure of the Ag(I) complex shows it to have a pseudo tetrahedral structure. 'Metal-free' phendio and the Cu(II) and Ag(I) phendio complexes strongly inhibit the growth of the fungal pathogen Candida albicans, and are more active than their 1,10-phenanthroline analogues. The simple Ag(I) salts, AgCH 3 CO 2 , AgNO 3 and AgClO 4 .H 2 O display superior anti-fungal properties compared to analogous simple Cu(II) and Mn(II) salts, suggesting that the nature of the metal ion strongly influences activity. Exposing C. albicans to 'metal-free' phendio, simple Ag(I) salts and [Ag(phendio) 2 ]ClO 4 causes extensive, non-specific DNA cleavage. 'Metal-free' phendio and [Ag(phendio) 2 ]ClO 4 induce gross distortions in fungal cell morphology and there is evidence for disruption of cell division. Both drugs also exhibit high anti-cancer activity when tested against cultured mammalian cells.

The chemisorbed system tellurium on Ni(111) has been studied using a lattice gas model with pair interactions as long range as sixth neighbor. We discover three distinct (2√3×2√3)R30 phases: low coverage (θ= (1)/(12) ), centered (θ= (1)/(6) ), and high coverage (θ= (1)/(4) ), when interactions are adjusted to match qualitatively the other features of the experimental phase diagram. Each pair of neighboring ordered phases is separated by a coexistence region at low temperatures. The low-coverage 2√3 phase disorders via a first-order transition at higher temperature. At higher coverage, a (√3×√3)R30 phase occurs at intermediate temperature. This phase melts by a first-order transition at low coverages and a continuous, three-state Potts transition at higher coverages. Thus, the simulations suggest that this chemisorbed system may provide an experimental realization of Potts tricritical behavior. Alternate sets of interactions in this long-range lattice gas model produce the (√7×√7)R19, (3×3), and (2×2) phases, which have been reported for other chemisorbed systems on triangular lattices.