Synthesis and Characterisation of Palladium(II) Complexes with 1,2-bis(N-methylbenzimidazolyl)Benzene

Zinc Complexes with Nitrogen Donor Ligands as Anticancer Agents

The search for anticancer metal-based drugs alternative to platinum derivatives could not exclude zinc derivatives due to the importance of this metal for the correct functioning of the human body. Zinc, the second most abundant trace element in the human body, is one of the most important micro-elements essential for human physiology. Its ubiquity in thousands of proteins and enzymes is related to its chemical features, in particular its lack of redox activity and its ability to support different coordination geometries and to promote fast ligands exchange. Analogously to other trace elements, the impairment of its homeostasis can lead to various diseases and in some cases can be also related to cancer development. However, in addition to its physiological role, zinc can have beneficial therapeutic and preventive effects on infectious diseases and, compared to other metal-based drugs, Zn(II) complexes generally exert lower toxicity and offer few side effects. Zinc derivatives have been proposed as antitumor agents and, among the great number of zinc coordination complexes which have been described so far, this review focuses on the design, synthesis and biological studies of zinc complexes comprising N-donor ligands and that have been reported within the last five years.

Synthesis and Spectral Studies of 2-Salicylidine-4-Aminophenyl Benzimidazole and its Reaction with Divalent Zn, Cd and Hg: Crystal Structure of the Cadmium Bromide Complex

2-salicylidine-4-aminophenyl benzimidazole (SAPbzlH, LH) has been synthesised and its complexes, formulated as ZnX2L y. nH2O (X = Cl, y = 1.5, n = 1; X = Br, y = 2, n = 2; X = CH3COO, y = 1.5, n = 2), CdX2L.CH3OH.0.5H2O (X = Cl, Br) and HgX2L.nH2O (X = Cl, n = 2; X = Br, n = 0), have been characterised. A single crystal X–ray diffraction study of [Cd2Br4L2].2CH3OH.H2O has revealed its binuclear structure with dibromide and SAPbzlH bridges, the environment around each metal ion being distorted trigonal bipyramidal. A similar structure is envisaged for the chloride analogue of cadmium as well as the mercury complexes.