Chiral bisphosphanes XII: Synthesis and molecular structure of cis-{rac,trans-1,2-bis[bis(morpholin-4-yl)-phosphino]cyclopentane}dimethylplatinum(II), cis-[C5H8{P[N(C2H4)2O-cyclo]2}2Pt(CH3)2]

Crystals of the title compound are monoclinic, space group P2₁/c, with a = 10.2621(8), b = 15.372(5), c = 17.612(2) Å, = 95.928(9)°, and Z = 4. Coordination about the central metal deviates slightly from ideal square-planar geometry. The five-membered chelate ring adopts an envelope conformation with one of the two P atoms (P1) deviating from the least-squares plane spanned by the central metal, the bridging CH carbons, and donor atom P2. While the morpholino substituents at the latter show little axial-equatorial discrimination for their orientation with respect to the coordination plane, the spatial alignments of the N(C₂H₄)₂O rings attached to P1 differ significantly between a more equatorial and a more axial disposition. The conformationally dissimilar arrangement of the two P donor groups within the envelope-like chelate ring manifests itself in unequal Pt–P bond lengths: d(Pt–P1) = 2.2677(16), d(Pt–P2) = 2.2825(16) Å. The Pt–CH₃ distances amount to 2.114(6) (trans to P2) and 2.141(6) Å (trans to P1), respectively.