Platinum Complexes of Naphthalene-l,8-dichalcogen and Related Polyaromatic Hydrocarbon Ligands

摘要

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 [PtCl_2(PPhR_2)] (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(PPh_3)_4] or [Pt(C_2H_4)(PMe_3)_2] (prepared in situ from [PtCl_2(PMe_3)_2],ethene and sodium naphthalide or super hydride [LiBEt_3H]) to give the appropriate platinum(II) species. The dilithium salts of l,8-E_2-naphthalene (E = S or Se) prepared in situ by reduction of the E-E bond with [LiBEt_3H] were treated with [PtCl_2(PPh_3)_2] to give [Pt(l,8-E_2-nap)(PPh_3)_2]. The tetra-oxides [Pt(l,8-(S(O)_2)_2-nap)(PR_3)_2] (PR_3 = PPh_3 or PMe_2Ph) were prepared in a similar metathetical manner from the appropriate [PtCl_2(PR_3)] complexes and the disodium salt of naphthalene 1,8-disulfinic acid (l,8-(S(O)ONa)_2-nap). The X-ray structures of selected examples reveal bidentate coordination with the naphthalene-E_2 unit hinged (111-137deg) with respect to the coordination plane. The naphthalene ring suffers significant distortion from planarity.