The formation of actinide-transition metal heterobimetallics mediated by a terminal actinide imido complex was comprehensively studied. The reaction of the thorium imido complex [(η -C Me ) Th=N(mesityl)(DMAP)] (3), prepared from [(η -C Me ) ThMe ] (1) and mesitylNH or [(η -C Me ) Th(NHmesityl) ] (2) in the presence of 4-(dimethylamino)pyridine (DMAP), with copper(I) halides gave the first thorium-copper heterobimetallic compounds [(η -C Me ) 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 Th atom. They are reactive species, as was shown by their reaction with the dimethyl complex [(η -C Me ) ThMe ] (1). Furthermore, a comparison between Th and early transition metals confirmed that Th exhibits distinctively different reactivity from d-transition metals.

Reduction of (η 5 -C 5 Me 5 ) 2 ThCl 2 (1) with potassium graphite (KC 8 ) in the presence of 2,2′-bipyridine forms the thorium bipy metallocene (η 5 -C 5 Me 5 ) 2 Th-(bipy) (2) in good yield. Complex 2 was fully characterized and reacts with various small molecules. For example, 2 serves as a source for the (η 5 -C 5 Me 5 ) 2 Th(II) fragment when exposed to conjugated alkynes, elemental sulfur and their organic derivatives, diazabutadiene, carbodiimide, CS 2 , isothiocyanate, and organic azides. Furthermore, treatment of 2 with ketone Ph 2 CO, thio-ketone Ph 2 CS, imine PhCHNPh, and nitrile PhCN results in C−C bond coupling products (η 5 -C 5 Me 5 ) 2 Th[(bipy)(Ph 2 CO)] (10), (η 5 -C 5 Me 5 ) 2 Th[(bipy)(Ph 2 CS)] (11), (η 5 -C 5 Me 5 ) 2 Th[(bipy)(PhCHNPh)] (12), and (η 5 -C 5 Me 5 ) 2 Th[(bipy)(PhCN)] (13), respectively, in quantitative conversion.

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 N 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.

The base-free thorium terminal imido [η 5 -1,2,4-(Me 3 C) 3 C 5 H 2 ] 2 ThN(p-tolyl) (1) activates a variety of small molecules such as pyridine derivatives, amines, boranes, chlorosilane, elemental selenium, and α,β-unsaturated esters. Reaction of 1 with pyridine, pyridine N-oxide, 2-methylpyridine N-oxide, p-toluidine, Ph 2 NH, 9-borabicyclo[3.3.1]-nonane (9-BBN), PhSiH 2 Cl, elemental selenium, PhSeSePh, and methyl methacrylate (MMA) formed the amido pyridyl complexes [η 5 -1,2,

The Lewis base supported thorium terminal imido metallocene (η5-C5Me5)2ThN­(mesityl)­(DMAP) (1) reacts with various small organic molecules such as thiazoles, silanes, internal acetylenes, nitriles, ketones, CS2, isothiocyanates, carbodiimides, lactides, organic azides, and diazoalkane derivatives. For example, while 1 forms the adduct (η5-C5Me5)2ThN­(mesityl)­(OPPh3) (2) with Ph3PO, deprotonation occurs between 1 and thiazole to give the amido thiazolyl complex (η5-C5Me5)2Th­(NHmesityl)­(C3H2NS) (3). Moreover, the five-membered metallaheterocycle (η5-C5Me5)2Th­[κ2-N,C-{N­(2-CH2-4,6-Me2C6H2)­(SiH2Ph)}]­(DMAP) (4) is isolated from a mixture of 1 and PhSiH3. In addition, treatment of 1 with PhCN, Ph2CHCN, or Me3SiCN gives the zwitterionic complex (η5-C5Me5)2Th­[κ-N-{NCPh­(N­(mesityl))}]­(DMAP) (5), and iminato compounds (η5-C5Me5)2Th­[N­(mesityl)­C­(CHPh2)­NH]­(NCCPh2) (6) and (η5-C5Me5)2Th­[2-{NC­(SiMe3)}-4-Me2NC5H3N]­(NC) (7), respectively. Furthermore, reaction of 1 with PhCCMe and Me3SiCCCCSiMe3 afford the amido pyridyl complexes (η5-C5Me5)2Th­[N­(mesityl)­C­(Me)CHPh]­(κ2-C,N-4-Me2NC5H3N) (8) and (η5-C5Me5)2Th­[N­(mesityl)­C­(C2SiMe3)CHSiMe3]­(κ2-C,N-4-Me2NC5H3N) (9), respectively. Treatment of 1 with N,N′-diisopropylcarbodiimide furnishes the [2 + 2] cycloaddition product (η5-C5Me5)2Th­[N­(mesityl)­C­(N i Pr)-N i Pr]­(DMAP) (10), whereas reaction of 1 with CS2 or PhNCS affords the four-membered metallaheterocycles (η5-C5Me5)2Th­[SCN­(mesityl)-S]­(DMAP) (11) and (η5-C5Me5)2Th­[SCN­(mesityl)-NPh]­(DMAP) (12), respectively. Moreover, while the four-membered metallaheterocycle (η5-C5Me5)2Th­[(μ-O)2(CPh2)]­(DMAP) (13) is formed upon addition of Ph2CO to 1, deprotonation occurs between 1 and 1-indanone to give the amido enolyl compound (η5-C5Me5)2Th­(NH­(mesityl))­(κ-O-1-OC9H7) (14). Nevertheless, the eight-membered metallaheterocycle (η5-C5Me5)2Th­[OCH­(Me)­C­(O)­OCH­(Me)­C­(N­(mesityl))­O] (15) is isolated from reaction of 1 with rac-lactide. Furthermore, while mixing 1 with (p-tolyl)­N3 affords the tetraazametallacyclopentene (η5-C5Me5)2Th­[N­(p-tolyl)­NNN­(p-tolyl)] (16), reaction of 1 with Me3SiCHN2 forms the bimetallic complex [(η5-C5Me5)2Th]2(μ-NNNCSiMe3)2 (17) concomitant with the elimination of mesitylene. The new complexes 2–15 and 17 were characterized by various spectroscopic techniques, including single-crystal X-ray diffraction studies.