Synthesis of Thorium(IV) and Uranium(IV) Salicylaldiminate Pseudo‐Halide Complexes

To explore the coordination chemistry of salicylaldiminate ligands as a non‐cyclopentadienyl ligand framework, we report the synthesis of their ThIV and UIV complexes. Deprotonation of (NC5H4)N=C(H)(3,5‐tBu2C6H2)OH (1), (NC9H6)N=C(H)(3,5‐tBu2C6H2)OH (2), and (CH3SC6H4)N=C(H)(3,5‐tBu2C6H2)OH (3) with sodium hydride and the subsequent addition of 0.5 equivalents of [UI4(1,4‐dioxane)2] yielded [{(NC5H4)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2UI2] (4), [{(NC9H6)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2UI2] (5), and [{(CH3SC6H4)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,S)}2UI2] (6), respectively. The reaction of 3 equivalents of the sodium salt of 1 afforded [{(NC5H4)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}3U]I3 (7). By using [ThCl4(dme)2], [{(NC5H4)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2ThCl2] (8) and [{(NC9H6)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2ThCl2] (9) were isolated. The metathesis of both chloride ligands in 9 with NaN3 led to a rare thorium azide product, [{(NC9H6)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2Th(N3)2] (10). The reaction of 5 with AgOTf (OTf = O3SCF3) afforded [{(NC9H6)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2U(OTf)2] (11), and the subsequent reaction of 11 with 2 equivalents of NaN3 provided [{(NC9H6)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2U(N3)2] (12). The reaction of 5 with 2 equivalents of AgNO3 produced [{(NC9H6)N=C(H)(3,5‐tBu2C6H2)O‐κ3(O,N,N′)}2U{NO3‐κ2(O,O)}2] (13). Each complex was characterized by 1H NMR and IR spectroscopy and, with the exception of 11, their structures were determined by X‐ray crystallographic analysis.