Crystal structures of three platinacyclic complexes bearing isopropyl eugenoxyacetate and pyridine derivatives

Abstract

Three new platinum(II) complexes bearing a eugenol and a pyridine derivative, namely (?-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-?C 1)chlorido(pyridine-?N)platinum(II), [Pt(C15H19O4)Cl(C5H5N)], (I), (?-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-?C 1)chlorido(4-methylpyridine-?N)platinum(II), [Pt(C15H19O4)Cl(C6H7N)], (II), and (?-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-?C 1)chlorido(pyridine-4-carboxylic acid-?N)platinum(II), [Pt(C15H19O4)Cl(C6H5NO2)], (III), have been synthesized and further characterized by single-crystal X-ray diffraction. The PtII atoms exhibit the usual distorted square-planar coordination and are surrounded by one Cl atom, one N atom, and a C atom and C=C double bond of the eugenol ligand. The donor N atom of the pyridine ligand occupies a cis position with respect to the double bond. Complexes (I) and (II) crystallize isomorphously in space group P and display a similar crystal packing characterized by C - H?O hydrogen bonding, C - H?p and p-p interactions. However, the presence of the additional methyl group in the 4-methylpyridine ligand in (II) disturbs the p-p interactions. The crystal packing of (III) is characterized by O - H?O hydrogen bonding, resulting in the formation of chains of molecules connected in a head-to-tail fashion and running in the [101] direction. The IC50 values for the HepG2 and KB cell lines are 150.9, 122.3µM for (I) and 138.9, 93.2µM for (II), respectively.