Description:
<jats:title>Abstract</jats:title><jats:p>The first representatives of phosphino(stibino)methanes R<jats:sub>2</jats:sub>PCH<jats:sub>2</jats:sub>Sb‐R′<jats:sub>2</jats:sub> (<jats:bold>3–5</jats:bold>) with bulky alkyl or cycloalkyl groups R and R′ were prepared in two steps from Ph<jats:sub>3</jats:sub>SnCH<jats:sub>2</jats:sub>I via the isolated stannylated phosphanes Ph<jats:sub>3</jats:sub>SnCH<jats:sub>2</jats:sub>PR<jats:sub>2</jats:sub> (<jats:bold>1, 2</jats:bold>) as intermediates. X‐ray structural analysis of <jats:bold>5</jats:bold> (R = C<jats:sub>6</jats:sub>H<jats:sub>11</jats:sub>, R′ = <jats:italic>t</jats:italic>Bu) reveals that the lone pairs and the substituents R and R′ at phosphorus and antimony and the hydrogen atoms of the CH<jats:sub>2</jats:sub> bridge adopt staggered conformations. Treatment of [{C<jats:sub>8</jats:sub>H<jats:sub>12</jats:sub>RhCl}<jats:sub>2</jats:sub>] with <jats:bold>3–5</jats:bold> affords the neutral compounds [Rh‐Cl(η<jats:sup>4</jats:sup>‐C<jats:sub>8</jats:sub>H<jats:sub>12</jats:sub>)(κ‐<jats:italic>P</jats:italic>‐R<jats:sub>2</jats:sub>PCH<jats:sub>2</jats:sub>SbR′<jats:sub>2</jats:sub>)] (<jats:bold>6–8</jats:bold>), of which <jats:bold>7 and 8</jats:bold> react with CH<jats:sub>3</jats:sub>MgI to give the corresponding methylrhodium derivatives [RhCH<jats:sub>3</jats:sub>(η<jats:sup>4</jats:sup>‐C<jats:sub>8</jats:sub>H<jats:sub>12</jats:sub>)(κ‐<jats:italic>P</jats:italic>‐R<jats:sub>2</jats:sub>‐PCH<jats:sub>2</jats:sub>SbR′<jats:sub>2</jats:sub>)] (<jats:bold>9, 10</jats:bold>). Cationic complexes [Rh(η<jats:sup>4</jats:sup>‐C<jats:sub>8</jats:sub>H<jats:sub>12</jats:sub>)(η<jats:sup>2</jats:sup>‐<jats:italic>P,Sb</jats:italic>‐R<jats:sub>2</jats:sub>PCH<jats:sub>2</jats:sub>SbR′<jats:sub>2</jats:sub>)]‐X (X = PF<jats:sub>6</jats:sub>: <jats:bold>11a, 12a, 13</jats:bold>; X = BPh<jats:sub>4</jats:sub>: <jats:bold>11b, 12b</jats:bold>) containing the phosphino(stibino)methanes as chelating ligands were obtained either from [{C<jats:sub>8</jats:sub>H<jats:sub>12</jats:sub>RhCl}<jats:sub>2</jats:sub>], R<jats:sub>2</jats:sub>PCH<jats:sub>2</jats:sub>SbR′<jats:sub>2</jats:sub> and MX, or (for <jats:bold>13</jats:bold>) from <jats:bold>8</jats:bold> and AgPF<jats:sub>6</jats:sub>. Compound <jats:bold>12a</jats:bold> (R = <jats:italic>i</jats:italic>Pr, R′ = <jats:italic>t</jats:italic>Bu) was characterized by X‐ray crystallography. The PF<jats:sub>6</jats:sub> salts <jats:bold>11a, 12a</jats:bold>, and <jats:bold>13</jats:bold> react with CH<jats:sub>2</jats:sub>N<jats:sub>2</jats:sub> by insertion of CH<jats:sub>2</jats:sub> into the Rh–Sb bond to yield the complexes <jats:bold>14–16</jats:bold>, the first examples of transition‐metal compounds with Sb ylides as ligands. Treatment of BPh<jats:sub>4</jats:sub> salts <jats:bold>11b</jats:bold> and <jats:bold>12b</jats:bold> with H<jats:sub>2</jats:sub> gives the half‐sand‐wich‐type complexes [(η<jats:sup>6</jats:sup>‐C<jats:sub>6</jats:sub>H<jats:sub>5</jats:sub>BPh<jats:sub>3</jats:sub>)Rh(κ<jats:sup>2</jats:sup>‐<jats:italic>P,Sb</jats:italic>‐R<jats:sub>2</jats:sub>PCH<jats:sub>2</jats:sub>SbR′<jats:sub>2</jats:sub>)] (<jats:bold>17, 18</jats:bold>), in which the tetraphenylborate is coordinated like a substituted arene to the metal center.</jats:p>