Reaction of the dinuclear chelate ring complex [Pt₂Cl₂(Saf-1H)₂], Saf-1H: deprotonated safrole, with various amines afforded cis-[Pt(Saf-1H)(Am)Cl], Am: NH₃ (1), Me₂NH (2), Et₂NH (3), morpholine (4), cyclohexylamine (5), benzylamine (6), aniline (7), o-toluidine (8), m-toluidine (9), p-toluidine (10), pyridine (11), 2-aminopyridine (12), and quinoline (13). The ¹H NMR and nuclear overhauser effect spectroscopy (NOESY) spectra of the reported complexes were accurately analyzed. NOESY spectra show that the complexes have a cis-configuration, in which the alkyl and aryl groups of coordinated amines are in proximity to the allyl group of chelating safrole. Complexes 11, 12, and 13 exhibit inhibitory activities on human cancer cells HepG2 and Lu with IC₅₀ = 2.5–5.0 µg mL⁻¹.

The reactions of cis‐[PtCl₂(DMSO)₂] (1) with either 1,3‐dibenzylimidazolium chloride (Bn₂‐imy·HCl) or 1,3‐dibenzylbenzimidazolium chloride (Bn₂‐bimy·HCl) in the presence of a base (Ag₂O/ Na₂CO₃/ CH₃COONa) afforded two mixed monocarbene‐dimethyl sulfoxide (DMSO) complexes, namely cis‐[PtCl₂(DMSO)(Bn₂‐imy)] (2) and cis‐[PtCl₂(DMSO)(Bn₂‐bimy)] (3), with the high yields. The structures of 1÷3 were elucidated by Pt analysis, EDX, IR and ¹H NMR spectra. The results show that the DMSO in 1÷3 coordinates with Pt(II) via the S atom, the deprotonated azolium salt is bound up with Pt(II) via the C atom (NCHN) and occupies cis‐position in comparison with the DMSO in 2 and 3.

For the first time, eugenol, a natural bioactive allylphenol, was introduced into coordination with platinum(II) by replacement of ethylene from Zeise’s salt with eugenol (Eug). The obtained complex, K[PtCl₃(Eug)] (1), was used as the key compound for preparation of the series of trans-[PtCl₂(Eug)(Amine)] (2–11), [PtCl(Eug)(8-O-quinoline)] (12) and [PtCl(Eug)(2-O₂C-quinoline)] (13). The synthesized complexes were characterized by elemental analyses, IR, ¹H NMR, ¹³C NMR, HSQS, HMBC, NOESY, and MS spectra. In 1–13 eugenol coordinates with Pt(II) at ethylenic double bond of the allyl group, the donor N of the amines is in trans-position in comparison with the double bond. A display of the trans-effect on the chemical shift of ¹H and ¹³C was remarked. Seven complexes were tested for cell in vitro cytotoxicity on human cancer cells. Complexes 3 and 12 exhibit high activities on Hep-G2 with IC₅₀ = 3.12 and 5.29 μM; 12 gives high activity against KB, Lu and MCF-7 with IC₅₀ = 0.43, 2.95 and 1.84 μM, respectively. Most of these IC₅₀ are lower than those of cisplatin.