A Nuclear Magnetic Resonance Study of the Binding of Trimethylphosphine Selenide to Cadmium Oleate

We report an NMR study on the binding of trimethylphosphine selenide (Se=PMe3) to cadmium oleate (Cd(OA)(2)) in CDCl3 and toluene-d(8). At room temperature in CDCl3, Se=PMe3 binds to Cd(OA)(2) in 1:1 ratio with a binding constant of 20 +/- 3 as determined by NMR titration. The Cd-bound and free Se=PMe3 are in fast exchange on the NMR time scale at room temperature and gives only one P-31 NMR peak. At ca. 190 K, three P-31 NMR peaks were observed for a toluene-d(8) solution of 1:1 mixture of Cd(OA)(2) and Se=PMe3. These three peaks were tentatively assigned to free Se=PMe3 (9.0 ppm), 1:1 (19.5 ppm), and 2:1 complex between Se=PMe3 and Cd(OA)(2) (18.8 ppm).