Crystal structure of bis(diphenylphosphino)ethane bis(2-selenopyridinato)platinum(II).

attracted considerable attention in recent years due to their diverse structural possibilities and relevance in materials science.1–3 Mononuclear cis complexes, [M(ER)2L2], are useful precursors for the synthesis of biand poly-nuclear complexes.2,3 These complexes are usually derived from simple organochalcogenolate ions. Internally functionalized organochalcogenolates, such as 2-selenopyridinate, would provide additional donor sites and, consequently, may result in a new structural motif.5 The structure of one such complex [Pt(Sepy)2(dppe)] is reported herein. A schematic diagram of [Pt(Sepy)2(dppe)] is shown in Fig. 1. Thermal ellipsoids of [Pt(Sepy)2(dppe)] are shown in Fig. 2. Crystal and experimental data are listed in Table 1. The fractional atomic coordinates and equivalent thermal paprameters for all of the refined atoms are given in Table 2. The platinum atom exists in a square-planar geometry defined by two cis selenium atoms derived from the 2-selenopyridinate ion and two phosphorus atoms of the chelating dppe ligand. Heavier atoms are all in a plane, whereas two carbon atoms of the dppe ligand are out of plane by the same extent on either side (±0.37 Å). The Pt–Se distances of 2.4335(13)Å and 2.4980(14)Å are clearly not equivalent. The distances can be compared with the M–Se distances reported for [Pt(SePh)2(dppe)] and [Pd(SePh)2(dppe)]. The Pt–P2, Pt–Se2 and P–C2,3 are in good agreement with those reported earlier. The P–Pt–P (85.3(9) ̊) and Se–Pt–Se (81.52(5) ̊) angles are significantly reduced from the normal bond angles of 90 ̊. The latter angle is usually acute; the E–M–E angles (E = S or Se; M 565 ANALYTICAL SCIENCES APRIL 2001, VOL. 17 2001 © The Japan Society for Analytical Chemistry