A series of new ethylenediamine (en) platinum(IV) complexes of the type Pt(IV)enX2A2
, with X2 =
cyclobutane-1,1-dicarboxylato (CBDCA), dichloro or bis(decanoato) and A = acetato,
dodecanoato, tetradecanoato, hexadecanoato, octadecanoato, adamantanecarboxylato (Ad) or
3α, 12α
-diformoxy-5β-cholato (DFCA) were synthesized and characterized by elemental analysis,
infrared and NMR (H1 and C13)
spectroscopic techniques.
Previous platinum(IV) compounds were usually restricted to trans-dihydroxo or trans-dichloro
platinum(IV) complexes. Recently trans-dicarboxylato platinum(IV) complexes with mainly acetate,
trifluoracetate or short-chain carboxylate groups (<11 carbons) in the axial position have been
described in the literature[1,2,3].
In this paper we report on the synthesis and characterization of a new class of ethylenediamine
platinum(IV) compounds that have high lipophilic long-chain carboxylate ligands either in the axial
or equatorial position. The platinum(IV) compounds with the lipophilic trans-carboxylate ligands in
the axial position were prepared by acylation of the trans-dihydroxo platinum(IV) species using an
acyl halide in the presence of pyridine. In contrast to previous publications[1]
the yields were
excellent (up to 94%!).