Synthesis and structure of organoplatinum(II) complexes containing aryl olefins and 8-hydroxyquinolines

Abstract

Twelve new organoplatinum(II) complexes: [PtCl(Saf)(2-Me-8-OquiN)] (1), [PtCl(Saf)(5,7-Cl2-8-OquiN)] (2), [PtCl(Saf)(5,7-Cl2-2-Me-8-OquiN)] (3), [PtCl(Meteug)(5,7-Cl2-8-OquiN)] (4), [PtCl(Meteug)(5,7-Cl2-2-Me-8-OquiN)] (5), [Pt(Saf-1H)(2-Me-8-OquiN)] (6), [Pt(Saf-1H)(5,7-Cl2-8-OquiN)] (7), [Pt(Saf-1H)(5,7-Cl2-2-Me-8-OquiN)] (8), [Pt(Eteug-1H)(2-Me-8-OquiN)] (9), [Pt(Eteug-1H)(2-OHC-8-OquiN)] (10), [Pt(Eteug-1H)(5,7-Cl2-8-OquiN)] (11) and [Pt(Eteug-1H)(5,7-Cl2-2-Me-8-OquiN)] (12) (Saf: Safrole, Meteug: Methyl eugenoxyacetate, Saf-1H: Deprotonated safrole, Eteug-1H: Deprotonated ethyl eugenoxyacetate, OquiN: substituted quinolin-8-olate) were synthesized. These complexes were characterized by elemental analyses, IR, 1H NMR, for several also by NOESY, MS spectra and 9 by single-crystal X-ray diffraction. It is shown that in 1-5 the Pt(II) ion is surrounded by a Cl ion and the ethylenic double bond of the aryl olefin, and by N and O atoms of the 8-OquiN, its donor N is in trans-position in comparison with the ethylenic double bond. In 6-12 the Pt(II) ion is surrounded by an aromatic C atom and the ethylenic C = C double bond of the aryl olefin, and by N and O atoms of the 8-OquiN resulting in a slightly distorted square-planar coordination environment; the donor N is in cis-position in comparison with the ethylenic double bond. Complexes 2, 4 and 7 exhibit high activities on human cancer cells KB, Hep-G2, Lu and MCF-7 with most IC50 values lower than those of cisplatin.