Influence of H<sub>2</sub>S and Thiols on the Binding of Alkenes and Alkynes to ReS<sub>4</sub><sup>-</sup>:  The Spectator Sulfido Effect DopkeJoel A. WilsonScott R. RauchfussThomas B. 2000 The three-component reaction of ReS<sub>4</sub><sup>-</sup> (<b>1</b>), H<sub>2</sub>S, and unsaturated substrates (un = alkene, alkyne) affords the Re<sup>V</sup> derivatives Re(S)(S<sub>2</sub>un)(SH)<sub>2</sub><sup>-</sup>. These adducts arise via the addition of H<sub>2</sub>S to intermediate dithiolates ReS<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>R<sub>4</sub>)<sup>-</sup> and dithiolenes ReS<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>R<sub>2</sub>)<sup>-</sup>. The species {ReS[S<sub>2</sub>C<sub>2</sub>(tms)<sub>2</sub>](SH)<sub>2</sub>}<sup>-</sup>, [ReS(S<sub>2</sub>C<sub>7</sub>H<sub>10</sub>)(SH)<sub>2</sub>]<sup>-</sup> (<b>3</b>), and [ReS(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)(SH)<sub>2</sub>]<sup>-</sup> are prepared according to this route. Similarly, the selenolate−thiolate complex [ReS(S<sub>2</sub>C<sub>7</sub>H<sub>10</sub>)(SeH)(SH)]<sup>-</sup> (<b>5</b>) is produced by the reaction of [ReS<sub>2</sub>(S<sub>2</sub>C<sub>7</sub>H<sub>10</sub>)]<sup>-</sup> with H<sub>2</sub>Se. The corresponding reactions using benzenethiol in place of H<sub>2</sub>S afford the more thermally robust adducts {ReS[S<sub>2</sub>C<sub>2</sub>(tms)<sub>2</sub>](SH)(SPh)}<sup>-</sup>, [ReS(S<sub>2</sub>C<sub>7</sub>H<sub>10</sub>)(SH)(SPh)]<sup>-</sup> (<b>7</b>), and [ReS(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)(SH)(SPh)]<sup>-</sup>. Norbornanedithiolato compounds <b>3</b>,<b> 5</b>, and <b>7 </b>are obtained as pairs of isomers that differ in terms of the relative orientation of the norbornane bridgehead relative to the ReS unit. The reaction of [ReS(S<sub>2</sub>C<sub>7</sub>H<sub>10</sub>)(SD)<sub>2</sub>]<sup>-</sup> (<b>3</b>-<i>d</i><sub>2</sub>) with H<sub>2</sub>S to give <b>3</b> is proposed to proceed via elimination of D<sub>2</sub>S and subsequent addition of H<sub>2</sub>S. Variable-temperature <sup>1</sup>H NMR measurements on the equilibrium of [ReS(S<sub>2</sub>C<sub>6</sub>H<sub>12</sub>)(SPh)(SH)]<sup>-</sup> with <b>1</b>, 1-hexene, and PhSH gave the following results:  Δ<i>H</i> = −7 (±1) kJ·mol<sup>-1</sup>; Δ<i>S</i> = 23 (±4) J·mol<sup>-1</sup>·K<sup>-1</sup>. Solutions of ethanedithiol and <b>1</b> react with C<sub>2</sub>(tms)<sub>2</sub> and C<sub>2</sub>H<sub>4</sub> to give {ReS[S<sub>2</sub>C<sub>2</sub>(tms)<sub>2</sub>](S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)}<sup>-</sup> and [ReS(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)<sub>2</sub>]<sup>-</sup>, respectively, concomitant with loss of H<sub>2</sub>S. The pathway for the ethanedithiol reaction is examined using 2-mercaptoethanol, affording {ReS[S<sub>2</sub>C<sub>2</sub>(tms)<sub>2</sub>](SC<sub>2</sub>H<sub>4</sub>OH)}<sup>-</sup>, which does not cyclize. Treatment of a solution of diphenylbutadiyne and <b>1</b> with PhSH gives two isomers of the dithiolene {ReS(SH)(SPh)[S<sub>2</sub>C<sub>2</sub>Ph(C<sub>2</sub>Ph)]}<sup>-</sup>. The corresponding reaction of ethanedithiol, diphenylbutadiyne, and <b>1 </b>affords the 1,4-diphenylbutadiene-1,2,3,4-tetrathiolate complex {[ReS(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)]<sub>2</sub>(S<sub>4</sub>C<sub>4</sub>Ph<sub>2</sub>)}<sup>2-</sup>.