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

Abstract Eleven lanthanide compounds [Y(cinn) 3 ] ( 1 ), [La(cinn) 3 ] ( 2 ), [La(4-OMecinn) 3 ]·2H 2 O ( 3 ), [La(4-Clcinn) 3 ]·2H 2 O ( 4 ), [La(4-OMephac) 3 ]·4H 2 O ( 5 ), [La(4-Clphac) 3 ]·3H 2 O ( 6 ), [Ce(cinn) 3 ] ( 7 ), [Nd(cinn) 3 ] ( 8 ), [Sm(cinn) 3 ]·H 2 O ( 9 ), [Yb(cinn) 3 ] ( 10 ) and [Sm(4-OMephac) 3 ]·H 2 O ( 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, 1 H and 13 C 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%.