Synthesis and Photophysics of Luminescent Rhenium(I) Acetylides-Precursors for Organometallic Rigid-Rod Materials. X-ray Crystal Structures of [Re(tBu2bpy)(CO)3(tBuC.tplbond.C)] and [Re(tBu2bpy)(CO)3Cl]

A series of rhenium(I) diimine acetylide complexes [Re(tBu2bpy)(CO)3(RC≡C)] (R = tBu (2), Me3Si (3), Ph (4)) have been synthesized and shown to exhibit rich photoluminescent behavior at room temperature. The X-ray crystal structures of [Re(tBu2bpy)(CO)3(tBuC≡C)] and its precursor complex [Re(tBu2bpy)(CO)3Cl] have also been determined. Both 1 and 2 crystallize in the monoclinic space group P21/n with a = 16.814(1) Å, b =12.195(1) Å, c = 22.599(2) Å, and β = 100.87(1)° for 1 and a = 11.116(1) Å, b = 13.128(1) Å, c = 18.328(2) Å, and β = 94.49(1)° for 2.