ABSTRACT
The formation of actinide-transition metal heterobimetallics mediated by a terminal actinide imido complex was comprehensively studied. The reaction of the thorium imido complex [(η5 -C5 Me5 )2 Th=N(mesityl)(DMAP)] (3), prepared from [(η5 -C5 Me5 )2 ThMe2 ] (1) and mesitylNH2 or [(η5 -C5 Me5 )2 Th(NHmesityl)2 ] (2) in the presence of 4-(dimethylamino)pyridine (DMAP), with copper(I) halides gave the first thorium-copper heterobimetallic compounds [(η5 -C5 Me5 )2 Th(X){N(mesityl)Cu(DMAP)}] (X=Cl (4), Br (5), I (6)). Complexes 4-6 feature an unusual geometry with a short Th-Cu distance, which DFT studies attribute to a weak donor-acceptor bond from the Cu+ atom to the electropositive Th4+ atom. They are reactive species, as was shown by their reaction with the dimethyl complex [(η5 -C5 Me5 )2 ThMe2 ] (1). Furthermore, a comparison between Th and early transition metals confirmed that Th4+ exhibits distinctively different reactivity from d-transition metals.
ABSTRACT
The reaction of the base-free terminal thorium imido complex [{η(5)-1,2,4-(Me3C)3C5H2}2Th=N(p-tolyl)] (1) with p-azidotoluene yielded irreversibly the tetraazametallacyclopentene [{η(5)-1,2,4-(Me3C)3C5H2}2Th{N(p-tolyl)N=N-N(p-tolyl)}] (2), whereas the bridging imido complex [{[η(5)-1,2,4-(Me3C)3C5H2]Th(N3)2}2{µ-N(p-tolyl)}2][(n-C4H9)4N]2 (3) was isolated from the reaction of 1 with [(n-C4H9)4N]N3. Unexpectedly, upon the treatment of 1 with 9-diazofluorene, the NN bond was cleaved, an Nâ atom was transferred, and the η(2)-diazenido iminato complex [{η(5)-1,2,4-(Me3C)3C5H2}2Th{η(2)-[N=N(p-tolyl)]}{N=(9-C13H8)}] (4) was formed. In contrast, the reaction of 1 with Me3SiCHN2 gave the nitrilimido complex [{η(5)-1,2,4-(Me3C)3C5H2}2Th{NH(p-tolyl)}{N2CSiMe3}] (5), which slowly converted into [{η(5)-1,2,4-(Me3C)3C5H2}{η(5):κ-N-1,2-(Me3C)2-4-CMe2(CH2NN=CHSiMe3)C5H2}Th{NH(p-tolyl)}] (6) by intramolecular C-H bond activation. The experimental results are complemented by density functional theory (DFT) studies.
