A CuO incorporated TiO(2) catalyst was found to be an active photo-catalyst for the reduction of H(2)O under sacrificial conditions. The catalytic activity originates from the photogeneration of excited electrons in the conduction bands of both TiO(2) and CuO resulting in a build-up of excess electrons in the conduction band of CuO. Consequently, the accumulation of excess electrons in CuO causes a negative shift in the Fermi level of CuO. The efficient inter-particle charge transfer leads to a higher catalytic activity and the formation of highly reduced states of TiO(2)/CuO, which are stable even under oxygen saturated condition. Negative shift in the Fermi level of CuO of the catalyst TiO(2)/CuO gains the required over-voltage necessary for efficient water reduction reaction. The function of CuO is to help the charge separation and to act as a water reduction site. The amount of CuO and crystalline structure were found to be crucial for the catalytic activity and the optimum CuO loading was ca. approximately 5-10%(w/w).

The new RuII chloroquine complexes [Ru(η6-arene)(CQ)Cl2] (CQ = chloroquine; arene = p-cymene 1, benzene 2), [Ru(η6-p-cymene)(CQ)(H2O)2][BF4]2 (3), [Ru(η6-p-cymene)(CQ)(en)][PF6]2 (en = ethylenediamine) (4), and [Ru(η6-p-cymene)(η6-CQDP)][BF4]2 (5, CQDP = chloroquine diphosphate) have been synthesized and characterized by use of a combination of NMR and FTIR spectroscopy with DFT calculations. Each complex is formed as a single coordination isomer: in compounds 1–4 chloroquine binds to ruthenium in the η1-N mode through the quinoline nitrogen atom whereas in complex 5 an unprecedented η6 bonding through the carbocyclic ring is observed. Compounds 1, 2, 3, and 5 are active against CQ-resistant (Dd2, K1 and W2) and CQ-sensitive (FcB1, PFB, F32 and 3D7) malaria parasites (Plasmodium falciparum); importantly, the potency of these complexes against resistant parasites is consistently higher than that of the standard drug chloroquine diphosphate. Complexes 1 and 5 also inhibit the growth of colon cancer cells, independently of the p53 status and of liposarcoma tumor cell lines with the latter showing increased sensitivity, especially to complex 1 (IC50 8 µM); this is significant because this type of tumor does not respond to currently employed chemotherapies.