Syntheses, photophysics, and X-ray structural characterization of dinuclear platinum(II) acetylide complexes, [Pt2(μ-dppm)2(μ-PhC≡C)(PhC≡C) 2]ClO4 and [Pt2(μ-dppm)2(μ-1BuC≡)( tBuC≡C)Cl]ClO4

Abstract

Refluxing an ethanolic solution of [Pt(dppm-P,P′)2]Cl2 with Hg(PhC≡C)2 in ethanol gave air-stable [Pt2(μ-dppm)2(μ-PhC≡C) (PhC≡C)2]+ as the major product, isolated as the Cl- or ClO4 - (1) salt. A similar reaction with Hg(tBuC≡C)2 gave [Pt2(μ-dppm)2(μ-tBuC≡C) (tBuC≡C)-Cl]+ instead, also isolated as the Cl- or ClO4 - (2) salt. The crystal structures of 1 and 2 have been determined by X-ray diffraction. Compound 1 crystallizes in the monoclinic space group C2/c with Z = 4 in a unit cell of dimensions a = 27.942(7) Å, b = 11.218(4) Å, c = 25.720(7) Å, and β = 124.22(2)°. Compound 2 crystallizes in the triclinic space group P1 with Z = 2 in a unit cell of dimensions a = 11.783(3) Å, b = 12.791(3) Å, c = 21.210(7) Å, α = 89.11(3)°, β = 77.41(2)°, and γ = 71.50(2)°. Both structures have been solved by Patterson and Fourier methods and refined by full-matrix least squares on the basis of 5203 observed reflections to R and Rw values of 0.038 and 0.048 for 1 and 9724 observed reflections to R and Rw values of 0.033 and 0.044 for 2, respectively. Both complexes have been found to exhibit long-lived photoluminescence both in the solid state and in fluid solutions (solid-state emission: 1, λem = 618 nm, τo = 2.2 ± 0.2 μs; 2, λem = 621 nm, τo = 3.5 ± 0.3 μs). The phosphorescent state of 1 has been shown to be quenched by pyridinium acceptors. © 1993 American Chemical Society.