Four Thallium(I) Ions Sandwiched by Two Tetraalkynylplatinate ([Pt(C⋮CR)₄]²^-) Fragments: Synthesis and Luminescent Behavior of Pt₂Tl₄ Species

Abstract

Hexanuclear platinum−thallium complexes [Pt2Tl4(C⋮CR)8] (R = tBu (1), Ph (2), SiMe3 (3)) have been constructed by starting from the homoleptic species [Pt(C⋮CR)4]2- and TlNO3. X-ray analysis of [Pt2Tl4(C⋮CtBu)8] (1) reveals that two eclipsed [Pt(C⋮CtBu)4]2- fragments are connected by four bridging thallium(I) ions. Each Tl(I) is positioned away from the Pt fragments and interacts asymmetrically with four alkynyl ligands (μ3-η2:σ(Pt):η2(Tl,Tl)), forming approximately the square-pyramidal geometry A4Tl (A = midpoint of Cα⋮Cβ) with the Tl at the apex. The optical properties of these complexes are presented.