Dithio- and Diselenophosphinate Thorium(IV) and Uranium(IV) Complexes: Molecular and Electronic Structures, Spectroscopy, and Transmetalation Reactivity

We report a comparison of the molecular and electronic structures of dithio- and diselenophosphinate, (E2PR2)1– (E = S, Se; R = iPr, tBu), with thorium(IV) and uranium(IV) complexes. For the thorium dithiophosphinate complexes, reaction of ThCl4(DME)2 with 4 equiv of KS2PR2 (R = iPr, tBu) produced the homoleptic complexes, Th(S2PiPr2)4 (1S-Th-iPr) and Th(S2PtBu2)4 (2S-Th-tBu). The diselenophosphinate complexes were synthesized in a similar manner using KSe2PR2 to produce Th(Se2PiPr2)4 (1Se-Th-iPr) and Th(Se2PtBu2)4 (2Se-Th-tBu). U(S2PiPr2)4, 1S-U-iPr, could be made directly from UCl4 and 4 equiv of KS2PiPr2. With (Se2PiPr2)1–, using UCl4 and 3 or 4 equiv of KSe2PiPr2 yielded the monochloride product U(Se2PiPr2)3Cl (3Se-UiPr-Cl), but using UI4(1,4-dioxane)2 produced the homoleptic U(Se2PiPr2)4 (1Se-U-iPr). Similarly, the reaction of UCl4 with 4 equiv of KS2PtBu2 yielded U(S2PtBu2)4 (2S-U-tBu), whereas the reaction with KSe2PtBu2 resulted in the formation of U(Se2PtBu2)3Cl (4Se-UtBu-Cl). Using UI4(1,4-dioxa...