NaCu5(C2)3: The First Alkali Metal Transition Metal Acetylide with a Three‐dimensional Framework Structure

Abstract

AbstractBy heating the red residue of the reaction of NaC2H and CuI in liquid ammonia at 463 K for 30 min in a dynamic vacuum orange polycrystalline NaCu5(C2)3 is obtained. The crystal structure was solved and refined from X‐ray powder diffraction data (orthorhombic, Pnma, a = 732.80(2) pm, b = 1099.63(4) pm, c = 726.15(2) pm, Z = 4, RB = 0.030). It consists of a three‐dimensional framework of CuI and C22— ions with small channels running parallel to [100] and [001]. The sodium ions reside at the intersections of these channels. The vibrational spectra of NaCu5(C2)3 show some similarities with the spectra of phenylethynylcopper(I), but they are different to those of Cu2C2. Therefore NaCu5(C2)3 does probably not represent a crystalline model compound for the unknown structure of amorphous Cu2C2.