Platinum complexes of naphthalene-1,8-dichalcogen and related polyaromatic hydrocarbon ligands

Platinum bisphosphine complexes bearing dichalcogen-derivatised naphthalene, acenaphthene or phenanthrene ligands have been prepared by either oxidative addition to zero-valent platinum species or from [PtCl2(PPhR2)] (R =Ph or Me) and the disodium or dilithium salts of the parent disulfur, diselenide or mixed S/Se species. The parent naphthalene, acenaphthene and phenanthrene chalcogen compounds were treated with either [Pt(PPh3)(4)] or [Pt(C2H4)(PMe3)(2)] (prepared in situ from [PtCl2(PMe3)(2)], ethene and sodium naphthalide or super hydride [LiBEt3H]) to give the appropriate platinum(II) species. The dilithium salts of 1,8-E-2-naphthalene (E = S or Se) prepared in situ by reduction of the E-E bond with [LiBEt3H] were treated with [PtCl2(PPh3)(2)] to give [Pt(1,8-E-2-nap)(PPh3)(2)]. The tetraoxides [Pt(1,8-(S(O)(2))(2)-nap)(PR3)(2)] (PR3 = PPh3 or PMe2Ph) were prepared in a similar metathetical manner from the appropriate [PtCl2(PR3)] complexes and the disodium salt of naphthalene 1,8-disulfinic acid (1,8-(S(O)ONa)(2)- nap). The X-ray structures of selected examples reveal bidentate coordination with the naphthalene-E-2 unit hinged (111-137degrees) with respect to the coordination plane. The naphthalene ring suffers significant distortion from planarity.