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-d8. 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 (31)P NMR peak. At ca. 190 K, three (31)P NMR peaks were observed for a toluene-d8 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).