Transition metal complexes with bidentate ligand 2, 11‐Bis (diphenylphosphinomethyl)benzo[c]phenanthrene (1). X. Preparation and spectroscopic properties of cis‐[PtCl2 (1)] trans‐ and cis‐[PtH (PPh3) (1)] [BF4] and crystal and molecular structure of cis‐[PtCl2 (1)] · CHCl3

It is shown that ligand 1, designed to span trans‐positions, under appropriate conditions also gives cis‐mononuclear complexes of platinum (II). The structure of cis‐[PtCl2 (1)] (2) has been determined by single‐crystal X‐ray diffraction. The major distortion from square planar coordination is the P‐Pt‐P angle of 104.8°. Values of valence angles within the bidentate ligand indicate that this part of the molecule is very strained. Two phenyl groups, one on each phosphorus, lie almost parallel to each other separated by ca. 3.2–3.3 Å. The 1H‐NMR. data for this compound show that the π‐phenyl interactions observed in the solid state occur also in solution. The preparation and NMR.‐spectroscopic properties of trans‐ and cis‐[PtH(PPh3) (1)] [BF4] are reported.