The Preparation and Characterisation of Hetero‐ and Homobimetallic Complexes Containing Bridging Naphthalene‐1,8‐dithiolato Ligands

<jats:title>Abstract</jats:title><jats:p>Homo‐ and heterobimetallic complexes of the form [(PPh<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>(μ<jats:sup>2</jats:sup>‐1,8‐S<jats:sub>2</jats:sub>‐nap){ML<jats:sub><jats:italic>n</jats:italic></jats:sub>}] (in which (1,8‐S<jats:sub>2</jats:sub>‐nap)=naphtho‐1,8‐dithiolate and {ML<jats:sub><jats:italic>n</jats:italic></jats:sub>}={PtCl<jats:sub>2</jats:sub>} (<jats:bold>1</jats:bold>), {PtClMe} (<jats:bold>2</jats:bold>), {PtClPh} (<jats:bold>3</jats:bold>), {PtMe<jats:sub>2</jats:sub>} (<jats:bold>4</jats:bold>), {PtIMe<jats:sub>3</jats:sub>} (<jats:bold>5</jats:bold>) and {Mo(CO)<jats:sub>4</jats:sub>} (<jats:bold>6</jats:bold>)) were obtained by the addition of [PtCl<jats:sub>2</jats:sub>(NCPh)<jats:sub>2</jats:sub>], [PtClMe(cod)] (cod=1,5‐cyclooctadiene), [PtClPh(cod)], [PtMe<jats:sub>2</jats:sub>(cod)], [{PtIMe<jats:sub>3</jats:sub>}<jats:sub>4</jats:sub>] and [Mo(CO)<jats:sub>4</jats:sub>(nbd)] (nbd=norbornadiene), respectively, to [Pt(PPh<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>(1,8‐S<jats:sub>2</jats:sub>‐nap)]. Synthesis of cationic complexes was achieved by the addition of one or two equivalents of a halide abstractor, Ag[BF<jats:sub>4</jats:sub>] or Ag[ClO<jats:sub>4</jats:sub>], to [{Pt(μ‐Cl)(μ‐η<jats:sup>2</jats:sup>:η<jats:sup>1</jats:sup>‐C<jats:sub>3</jats:sub>H<jats:sub>5</jats:sub>)}<jats:sub>4</jats:sub>], [{Pd(μ‐Cl)(η<jats:sup>3</jats:sup>‐C<jats:sub>3</jats:sub>H<jats:sub>5</jats:sub>)}<jats:sub>2</jats:sub>], [{IrCl(μ‐Cl)(η<jats:sup>5</jats:sup>‐C<jats:sub>5</jats:sub>Me<jats:sub>5</jats:sub>)}<jats:sub>2</jats:sub>] (in which C<jats:sub>5</jats:sub>Me<jats:sub>5</jats:sub>=Cp*=1,2,3,4,5‐pentamethylcyclopentadienyl), [{RhCl(μ‐Cl)(η<jats:sup>5</jats:sup>‐C<jats:sub>5</jats:sub>Me<jats:sub>5</jats:sub>)}<jats:sub>2</jats:sub>], [PtCl<jats:sub>2</jats:sub>(PMe<jats:sub>2</jats:sub>Ph)<jats:sub>2</jats:sub>] and [{Rh(μ‐Cl)(cod)}<jats:sub>2</jats:sub>] to give the appropriate coordinatively unsaturated species that, upon treatment with [(PPh<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>Pt(1,8‐S<jats:sub>2</jats:sub>‐nap)], gave complexes of the form [(PPh<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>(μ<jats:sup>2</jats:sup>‐1,8‐S<jats:sub>2</jats:sub>‐nap){ML<jats:sub><jats:italic>n</jats:italic></jats:sub>}][X] (in which {ML<jats:sub><jats:italic>n</jats:italic></jats:sub>}[X]={Pt(η<jats:sup>3</jats:sup>‐C<jats:sub>3</jats:sub>H<jats:sub>5</jats:sub>)}[ClO<jats:sub>4</jats:sub>] (<jats:bold>7</jats:bold>), {Pd(η<jats:sup>3</jats:sup>‐C<jats:sub>3</jats:sub>H<jats:sub>5</jats:sub>)}[ClO<jats:sub>4</jats:sub>] (<jats:bold>8</jats:bold>), {IrCl(η<jats:sup>5</jats:sup>‐C<jats:sub>5</jats:sub>Me<jats:sub>5</jats:sub>)}[ClO<jats:sub>4</jats:sub>] (<jats:bold>9</jats:bold>), {RhCl(η<jats:sup>5</jats:sup>‐C<jats:sub>5</jats:sub>Me<jats:sub>5</jats:sub>)}[BF<jats:sub>4</jats:sub>] (<jats:bold>10</jats:bold>), {Pt(PMe<jats:sub>2</jats:sub>Ph)<jats:sub>2</jats:sub>}[ClO<jats:sub>4</jats:sub>]<jats:sub>2</jats:sub> (<jats:bold>11</jats:bold>), {Rh(cod)}[ClO<jats:sub>4</jats:sub>] (<jats:bold>12</jats:bold>); the carbonyl complex {Rh(CO)<jats:sub>2</jats:sub>}[ClO<jats:sub>4</jats:sub>] (<jats:bold>13</jats:bold>) was formed by bubbling gaseous CO through a solution of <jats:bold>12</jats:bold>. In all cases the naphtho‐1,8‐dithiolate ligand acts as a bridge between two metal centres to give a four‐membered PtMS<jats:sub>2</jats:sub> ring (M=transition metal). All compounds were characterised spectroscopically. The X‐ray structures of <jats:bold>5</jats:bold>, <jats:bold>6</jats:bold>, <jats:bold>7</jats:bold>, <jats:bold>8</jats:bold>, <jats:bold>10</jats:bold> and <jats:bold>12</jats:bold> reveal a binuclear PtMS<jats:sub>2</jats:sub> core with Pt⋅⋅⋅M distances ranging from 2.9630(8)–3.438(1) Å for <jats:bold>8</jats:bold> and <jats:bold>5</jats:bold>, respectively. The napS<jats:sub>2</jats:sub> mean plane is tilted with respect to the PtP<jats:sub>2</jats:sub>S<jats:sub>2</jats:sub> coordination plane, with dihedral angles in the range 49.7–76.1° and the degree of tilting being related to the Pt⋅⋅⋅M distance and the coordination number of M. The sum of the Pt(1)coordination plane/napS<jats:sub>2</jats:sub> angle, a, and the Pt(1)coordination plane/M(2)coordination plane angle, b, a+b, is close to 120° in nearly all cases. This suggests that electronic effects play a significant role in these binuclear systems.</jats:p>