Triorganophosphine-dithiomonometaphosphoryl halides

Abstract

The title compounds, ethyldiphenylphosphine- dithiomonometaphosphoryl chloride, EtPh2P --> PS2Cl, C14H15ClP2S2, (I), and tris-n-propylphosphine- dithiomonometaphosphoryl chloride and bromide, (Pr3P)-Pr-n --> PS2Cl, C9H21ClP2S2, (II), and nPr(3)P --> PS2Br, C9H21BrP2S2, (III), respectively, are the first phosphine-stabilized dithiomonometaphosphoryl halides to be structurally characterized. In the tris-n-propylphosphine derivatives, the central P --> P donor-acceptor bond becomes longer in the order bromo < chloro < fluoro. Substitution of the tris-n- propylphosphine group in (II) by the more bulky ethyldiphenylphosphine group also leads to a longer P --> P bond. These structural features agree with the observed 31 P NMR data. In (II) and (III), the central P-P bond coincides with the crystallographic threefold axis, entailing site- occupational disorder for the S2Y group