A Lewis-Base-Supported\nTerminal Thorium Imido Metallocene\n[{η<sup>5</sup>‑1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>ThN(<i>p</i>‑to

Addition of <i>p</i>-tolylN<sub>3</sub> to\na toluene\nsolution of thorium bipyridyl metallocene [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th(bipy)]\n(<b>1</b>) causes N<sub>2</sub> evolution concomitant with the\nformation of Lewis-base-supported terminal thorium imido metallocene\n[{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>ThN(<i>p</i>-tolyl)(bipy)]\n(<b>2</b>). Complex <b>2</b> may initiate [2 + 2] or [2\n+ 1] cycloaddition reactions with internal alkynes PhCCPh\nand PhCCCCPh, thiobenzophenone Ph<sub>2</sub>CS, organic\nnitriles such as PhCH<sub>2</sub>CN and C<sub>6</sub>H<sub>11</sub>CN, and organic isonitriles such as 2,6-Me<sub>2</sub>PhNC and C<sub>6</sub>H<sub>11</sub>NC, yielding the amido complex [{η<sup>5</sup>-1-(CH<sub>2</sub>Me<sub>2</sub>Si)-2,4-(Me<sub>3</sub>Si)<sub>2</sub>C<sub>5</sub>H<sub>2</sub>}{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}Th{N(<i>p</i>-tolyl)C(Ph)CH(Ph)}] (<b>3</b>), five-membered heterocyclic\ncomplex [{η<sup>5</sup>-1-(<i>p</i>-tolyl)NC(Ph)CHCC(Ph)CH<sub>2</sub>SiMe<sub>2</sub>-2,4-(Me<sub>3</sub>Si)<sub>2</sub>C<sub>5</sub>H<sub>2</sub>}{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}Th] (<b>4</b>), disulfido complex\n[{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th(S<sub>2</sub>CPh<sub>2</sub>)] (<b>6</b>), iminato complexes [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th{η<sup>3</sup>-N(<i>p</i>-tolyl)C(CH<sub>2</sub>Ph)NH}(NCCHPh)]\n(<b>8</b>) and [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th{η<sup>3</sup>-N(<i>p</i>-tolyl)C(C<sub>6</sub>H<sub>11</sub>)NH}{NCC(CH<sub>2</sub>)<sub>5</sub>}] (<b>9</b>), eight-membered heterocyclic\ncomplex [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th{N(<i>p</i>-tolyl)C(N-2,6-Me<sub>2</sub>Ph)C(H)N(6-MePh-2-CH<sub>2</sub>)}] (<b>11</b>), and bis-amido complex [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th{1-C<sub>6</sub>H<sub>11</sub>-2,2-(CH<sub>2</sub>)<sub>5</sub>-4-(<i>p</i>-tolyl)N-5-C<sub>6</sub>H<sub>11</sub>N-(1,3-C<sub>4</sub>HN<sub>2</sub>)}] (<b>12</b>), respectively. Moreover, with\nchlorosilane PhSiH<sub>2</sub>Cl complex <b>2</b> converts to\nthorium amido chloride complex [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th(Cl){N(<i>p</i>-tolyl)SiH<sub>2</sub>Ph}] (<b>13</b>), demonstrating\nthat the thorium imido fragment may also act as a nucleophile. Nevertheless,\ncomplex <b>2</b> may also initiate deprotonation reactions as\nshown by its reactivity with the imine (<i>p</i>-tolyl)<sub>2</sub>CNH and thiazole to yield the amido–iminato\ncomplex [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th{NH(<i>p</i>-tolyl)}{NC(<i>p</i>-tolyl)<sub>2</sub>}] (<b>14</b>) and amido thiazolyl\ncompound [{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}<sub>2</sub>Th{NH(<i>p</i>-tolyl)}(C<sub>3</sub>H<sub>2</sub>NS)] (<b>15</b>), respectively. Last, but\nnot the least, the cyclopentadienyl ligand [1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>]<sup>−</sup> of <b>2</b> can also be protonated by the terminal alkyne PhCCH, 1-indanone,\nand the nitrile Ph<sub>2</sub>CHCN to yield dimeric half-sandwich\ncompounds [{{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}Th(C<sub>2</sub>Ph)(bipy)}<sub>2</sub>{μ-N(<i>p</i>-tolyl)}<sub>2</sub>] (<b>5</b>), [{{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}Th(1-O-CC<sub>8</sub>H<sub>7</sub>)(bipy)}<sub>2</sub>(μ-O)<sub>2</sub>] (<b>7</b>), and [{{η<sup>5</sup>-1,2,4-(Me<sub>3</sub>Si)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>}Th(NNCPh<sub>2</sub>)(bipy)}<sub>2</sub>{μ-N(<i>p</i>-tolyl)}<sub>2</sub>] (<b>10</b>), respectively.