Reactions of Tris(o-N,N-dimethylaminobenzyl)cerium(III) with Oxidizing Agents, Dichalcogenides, and a Thiophosphinic Amide Ligand

Reactions of a cerium(III) o-N,N-dimethylaminobenzyl (DMAB) complex with oxidizing agents, dichalcogenides, and a thiophosphinic amide have been studied. Treatment of the reported homoleptic DMAB complex [Ce(DMAB)3] (1) with Ag(OTs) (OTs– = tosylate) and Ag(OTf) (OTf– = triflate) in tetrahydrofuran (thf) afforded [Ce4(DMAB)6(μ-OTs)6(thf)2] (2) and [Ce(DMAB)2(OTf)(thf)2] (3), respectively. Reactions of 1 with CuI and CuCl led to isolation of [Ce(DMAB)2I] (4) and [Cu4(DMAB)4], respectively. Treatment of 1 with PhEEPh (E = S, Se) and tetramethylthiuram disulfide ([Me2NC(S)S]2) in thf afforded [Ce2(DMAB)2(EPh)(μ-EPh)3(thf)2] (E = S (5a), Se (5b)) and [Ce{S2CNMe2}3(thf)2], respectively. In the presence of 1,3,4,6,7,8-hexahydro-2Hpyrimido[1,2-a]pyrimidine (hppH), the reaction of 1 with 2,2′-dipyridyl disulfide ([PyS]2) yielded [Ce2(PyS)4(μ-hpp)2] (6). Protonolysis of 1 with a bis(thiophosphinic amido)amine ligand, H2L, afforded [Ce(L)(DMAB)(thf)] (7) that reacted with Ag(OTf) to give [Ce(L)(OTf)(thf)2] (8). Migratory insertion of 7 with N,N′-dicyclohexylcarbodiimide and phenyl isothiocyanate resulted in the formation of an amidine (9) and a thioacetamido (10) complex, respectively. The crystal structures of the Ce-DMAB complexes have been determined.