Dual investigation of lanthanide complexes with cinnamate and phenylacetate ligands: Study of the cytotoxic properties and the catalytic oxidation of styrene

Eleven lanthanide compounds [Y(cinn)3] (1), [La(cinn)3] (2), [La(4-OMecinn)3]·2H2O (3), [La(4-Clcinn)3]·2H2O (4), [La(4-OMephac)3]·4H2O (5), [La(4-Clphac)3]·3H2O (6), [Ce(cinn)3] (7), [Nd(cinn)3] (8), [Sm(cinn)3]·H2O (9), [Yb(cinn)3] (10) and [Sm(4-OMephac)3]·H2O (11) containing carboxylato ligands (cinn = cinnamate; 4-OMecinn = 4-methoxicinnamate; Clcinn = 4-chlorocinnamate; 4-OMephac = 4-methoxyphenylacetate; 4-Clphac = 4-chlorophenylacetate) have been synthesized and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy, thermal analysis and X-ray diffraction powder patterns. In addition, compound 11 was characterized by single crystal X-ray diffraction studies. The cytotoxic activity of these complexes has been tested against three different human tumour cell lines HL60 (human promyelocytic leukemia), K562 (human erythromyeloblastoid leukemia) and MCF7 (breast cancer), observing a very modest cytotoxic activity for all tested compounds. In addition, toxicity tests to macrophages and erythrocytes have also been carried out, observing that none of the compounds is toxic against these immunocompetent cells. Finally, all the synthesized compounds have been tested as catalysts for styrene oxidation observing conversions higher than 50% after 19 h of reaction as well as a relatively high selectivity to two main products benzaldehyde (BzA) and 1-phenylethane-1,2-diol (PhED). Complex 7 presents the higher conversion (99.56%) with a relatively high selectivity towards PhED of 72.07%.

Eleven lanthanide compounds with phenylacetate or cinnamate ligands have been synthesized and structurally characterized. The toxicity of these complexes towards macrophages and erythrocytes, as well as the cytotoxicity against human cancer cell lines has been reported. In addition, the catalytic properties of these compounds in the oxidation of styrene have also been studied.Figure optionsDownload as PowerPoint slide