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Although several strategies have been established to circumvent the limitations of platinum-based chemotherapy, the basic problems still persist. For this purpose, the new series of heterobimetallic formulations [FcLnSnPh3] (1, 3, and 9)], [FcLnSnBu3]n(2, 4and 8), [FcL3SnCy3] (10), and [FcL3SnR3(MeOH)] (R = Me (5), Et (6), or Pr (7)), where FcLn(n= 1–3) refers to the isomeric 2-/3-/4-ferrocenylbenzoates, was synthesized which can target cancer cells and successively support functional iron deficiencies during chemotherapy. Compounds 1–10have been characterized by elemental analysis, and their spectroscopic properties were investigated using IR, NMR, electronic, and fluorescence techniques. The molecular structures of metallo proligands FcL1H and FcL3H and the six heterobimetallic compounds 2, 3, 5–7, and 10have been determined by X-ray crystallography. The redox properties of FcLnH and their compounds 1–10were also investigated by cyclic voltammetry. In vitro cytotoxic activities of compounds 1–4, 8, and 9were assessed by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against human hepatic carcinoma (HepG2) cells, with IC50values revealing high activity better than that of doxorubicin. More importantly, compound 2demonstrated maximum inhibition in HepG2 cells (IC50= 0.10 μM) among other studied cell lines of human origin, e.g. embryonic kidney (HEK-293T), breast (MDA-MB-231), and lung (A-549) cancer cells, with negligible effect on human peripheral blood mononuclear cells (PBMC). Compound 2effectively inhibited cell viability, and the apoptosis proceeded via activation of caspases and cleavages of caspase-dependent proteins, as revealed from a PARP cleavage assay. Membrane microviscosity results point toward changes in fluidity that are sufficient to stop biological activities mediated by growth factors.

The catalytic activity of aqua complexes of the group III metals [M(H2O)n]3+(M = Ga, In, Sc, n= 6; M = Y, n= 8; M = La, n= 9) towards the oxidation of olefins with H2O2was investigated in detail by theoretical (DFT) methods. It was predicted and then confirmed in a preliminary experiment that these complexes formed from simple soluble salts in aqueous medium are able to efficiently catalyse the olefin oxidation. The reaction occurs viatwo competitive reaction channels which are realized concurrently, i.e.(i) hydroperoxidation of the allylic C atom(s) viaa radical Fenton-like mechanism involving HO radicals and leading to alkyl hydroperoxides ROOH and (ii) epoxidation of the CC bond through a one-step mechanism involving oxygen transfer from the hydroperoxo ligand in an active catalytic form [M(H2O)n−k(OOH)]2+(M = Ga, In, Y, La, k= 2; M = Sc, k= 1) to the olefin molecule and leading to epoxides and/or trans-diols. Other concerted and stepwise mechanisms of the epoxidation were also considered but found less favourable.

A simple catalytic system based on a soluble bismuth(iii) salt, Bi(NO3)3/H2O2/HNO3/CH3CN + H2O, exhibits pronounced activity towards the homogeneous oxidation of inert alkanes with the yield of oxygenate products up to 32% and TON up to 112. The experimental selectivity parameters and kinetic data together with theoretical DFT calculations indicate that the reaction occurs viaa free radical mechanism involving the formation of the HO radicals which directly react with alkane molecules. The mechanism of the HO generation (which is the rate limiting step of the whole process) includes the substitution of a water ligand for H2O2in the initial aqua complex [Bi(H2O)8]3+, hydrolysis of the coordinated H2O2, second H2O-for-H2O2substitution and the homolytic HO–OH bond cleavage in complex [Bi(H2O)4(H2O2)(OOH)]2+(6). The relatively low overall activation energy for this process (ca.20 kcal mol−1) is accounted for by the high lability and acidity of the Bi aqua complexes and tremendous activation of coordinated H2O2in 6towards homolysis.