The face-to-face complex trans-Rh(CO)Cl(μ-Ph2AsCH2PPh2) 2-cis-PtCl2, 1, isomerizes to trans-Rh-(CO)Cl2(μ-Ph2AsCH2PPh 2)2-trans-PtCl upon heating in chloroform or upon treatment with a small amount of Ph2AsCH2PPh2. Metathesis of 1 with iodide produces trans-Rh(CO)I2(μ-Ph2AsCH2PPh 2)2-trans-PtI, and the bromo analogue has been prepared similarly. trans-Rh(CO)Cl2(μ-Ph2AsCH2PPh 2)2-trans-PtCl·2CH2Cl2, 2, crystallizes in the monoclinic space group P21/c with a = 17.563 (4) Å, b = 14.995 (4) Å, c = 21.338 (4) Å, β = 105.90 (2)°, V = 5404 (2) Å3, and Z = 4, at 140 K. The structure was refined to a conventional R value of 0.051 using 6017 unique reflections and 334 parameters. trans-Rh(CO)I2(μ-Ph2AsCH2PPh 2)2-trans-PtI-CH2Cl 2·2CHCl3, 4, crystallizes in the orthorhombic space group Pbca with a = 17.808 (8) Å, b = 19.488 (8) Å, c = 35.228 (15) Å, V = 12225.6 (9) Å3, and Z = 8 at 140 K. The structure was refined to a conventional R value of 0.092 using 5001 unique data and 344 parameters. Both structures are similar with a six-coordinate rhodium atom (ligands: two As, CO, two Cl or two I, Pt) and a four-coordinate platinum (ligands two P, Rh, Cl or I) joined by a Pt-Rh bond (2.692 (1) Å in 2 and 2.737 (3) Å in 4). The carbonyl group in both complexes displays a subtle tilting toward the platinum atom. This results in a significant lowering (20-40 cm-1) of the carbonyl stretching frequency.
|Number of pages||7|
|Publication status||Published - 1985|
ASJC Scopus subject areas
- Inorganic Chemistry
- Organic Chemistry