LAUSR

In an attempt to synthesize heterometallic cerium nitrido complexes, we studied the reactions of cerium complexes supported by the Kläui tripodal ligand [Co(η5-C5H5){PO(OEt)2}3]- (LOEt-) with transition-metal nitrides. Whereas no reactions were found between Ce-LOEt complexes and [RuVI(LOEt)(N)Cl2] (2), treatment of the Ce(iv) oxo complex [CeIV(LOEt)2(O)(H2O)]·MeCONH2 (1) with 2 resulted in reduction of both the Ce(iv) and Ru(vi) complexes, and formation of a heterometallic Ce(iii)/Ru(iii) complex with a bridging deprotonated acetamide ligand, [(LOEt)2(H2O)CeIII{μ-O,N-MeC(O)NH}RuIII(LOEt)Cl2] (4), along with a minor product, [CeIII(LOEt)2(NO3)]. Ce(iv)-LOEt complexes such as [CeIV(LOEt)2Cl2] (3) can oxidize [ReV(LOEt)(N)(PPh3)Cl] to give the Re(vi) nitride [ReVI(LOEt)(N)(PPh3)Cl]+. Chloride abstraction of 3 by TlPF6 followed by reaction with [PPh4]2[MnV(N)(CN)4] afforded a diamagnetic red solid that is tentatively formulated as a heterometallic Ce(iv)/Mn(v) complex, [Ce(LOEt)2(H2O){Mn(N)(CN)4}] (5). Reactions of 3 with [nBu4N][MVI(N)(cat)2] (cat2- = catecholate(2-)) afforded the Ce(iii)/M(vi) complexes [(LOEt)2CeIII{(μ-cat)2MVI(N)}] [M = Ru (6), Os (7)], in which the Ce(iii) and M(vi) centers are bridged by two oxygen atoms of the two catecholate ligands. Similarly, the catecholate-bridged Ce(iii)/Re(v) complex [(LOEt)2CeIII{(μ-cat)2ReV(O)}] (8) was prepared from 3 and [Me4N][ReV(O)(cat)2]. In CH2Cl2, 8 was air-oxidized to the Ce(iii)/Re(vii) complex [CeIII(LOEt)2(H2O)2][cis-{ReVII(O)2(cat)2}] (9) with a cis-dioxo-Re(vii) counter-anion. The crystal structures of 4, 6, and 9 have been determined.