cis-3,4-Diaminocyclopentanol complexes of platinum(II)

A series of platinum(II) complexes have been prepared using cis-1,2-diaminocyclopentane and cis-3,4-diaminocyclopentanols; specifically, cis-[PtCl2(cis-1,2-diaminocyclopentane)] (A), cis-[PtCl2(cis,syn-3,4-diaminocyclopentanol)] (B), cis-[PtCl2(cis,anti-3,4-diaminocyclopentanol)] (C), and bis(cis,anti-3,4-diaminocyclopentanol)platinum(II) tetrachloroplatinate (D). The complexes were synthesized from K2PtCl4 and the corresponding cis-diamines. Crystal structures of the Pt(II) complexes have been determined by X-ray single crystal diffraction. Parameters are as follows: space group P21/n (no. 14), a=7.8133(4), b=13.5959(7), c=9.8561(7) Å, β=113.201(4)°, V=962.33(19) Å3, Z=4 for A; space group P21/n (no. 14), a=6.6076(2), b=11.3481(4), c=11.9739(4) Å, β=98.364(2)°, V=888.30(9) Å3, Z=4 for B; space group P21/c (no. 14), a=12.7358(2), b=20.8072(5), c=12.1253(3) Å, β=112.6139(13)°, V=2966.1(2) Å3, Z=12 for C; space group P21/c (no. 14), a=10.0248(3), b=8.9029(5), c=11.1253(6) Å, β=109.174(3)°, V=937.85(15) Å3, Z=2 for D. The coordination spheres about the Pt atoms are slightly distorted square planar geometries owing to the presence of the geometrically strained five-membered PtN2C2 ring.