cis-Bis(3,6-dihydro-2H-1,2-oxazine- N)diiodoplatinum(II) and cis-bis(3,4,5,6-tetrahydro-2H-1,2-oxazine-N)diiodoplatinum(II)

The title complexes, [Pt(C4H7NO)(2)I-2], (I), and [Pt(C4H9NO)(2) I-2], (II) , possess similar square-planar coordination geometries with modest distort ions from ideality. For (I), the cis-L-Pt-L angles are in the range 87.0 (4 )-94.2 (3)degrees, while the trans angles are 174.4 (3) and 176.4 (3)degree s. For (II), cis-L-Pt-L are 86.1 (8)-94.2 (6)degrees and trans-L-Pt-L are 1 74.4 (6) and 177.4 (5)degrees. One 3,6-dihydro-2H-1,2-oxazine ligand in (I) is rotated so that the N-O bond is out of the square plane by approximatel y 70 degrees, while the N-C bond is only ca 20 degrees out of the plane. Th e other oxazine ligand is rotated so that the N-C bond is about 80 degrees out of the plane, while the N-O bond is out of the plane by approximately 2 4 degrees. In (II), the 3,4,5,6-tetrahydro-2H-1,2-oxazine ligands are also positioned with one having the N-O bond further out of the plane and the ot her having the N-C bond positioned in that fashion. Both ligands, however, are rotated approximately 90 degrees compared with their positions in (I). In both complexes, this results in an unsymmetrical distortion of the I-Pt- N bond angles in which one is expanded and the other contracted. These feat ures are compared to those of reported cis-diaminediiodoplatinum(II) comple xes.