Synthesis, Light-Emitting, and Two-Photon Absorption Properties of Platinum-Containing Poly(arylene-ethynylene)s Linked by 1,3,4-Oxadiazole Units

A series of soluble and thermally stable group 10 platinum(II) polyyne polymers of the type [−C≡C−Pt(PBu3)2−C≡C−Ar−Ox−Ar−]n (where Ox = 1,3,4-oxadiazole; Ar = p-C6H4 or 2,7-dihexyl-9,9-fluorene) and [−C≡C−Pt(PBu3)2−C≡C−Ar−Ox−Ar−Ox−Ar−]n (where Ar = 2,7-dihexyl-9,9-fluorene) along with their corresponding dinuclear model compounds [Ph−Pt(PEt3)2−C≡C−Ar−]2−Ox− (where Ar = p-C6H4 or 2,7-dihexyl-9,9-fluorene) and [Ph−Pt(PEt3)2−C≡C−Ar−Ox−]2−Ar− (where Ar = 2,7-dihexyl-9,9-fluorene) were prepared and characterized. The regiochemical structure of the polymers has been ascertained by single-crystal X-ray analysis on the model compound [Ph−Pt(PEt3)2−C≡C−p−C6H4−]2−Ox−. The photophysical properties (absorption, excitation, emission, and nanosecond transient absorption spectra) of these metalated compounds in 2MeTHF at 298 and 77 K are reported. These findings are correlated by density functional theory (DFT) calculations. Geometry optimizations predict totally planar molecules for these metalated complexes and polyme...