| Abstract: | Synthesis, Crystal Structure, and Solid State MAS-NMR Spectroscopic Investigation of K5H(CN2)3 Single phase K5H(CN2)3 was synthesized by reaction of KHCN2 with metallic potassium in liquid ammonia or by reaction of KNH2 with melamine C3N3(NH2)3 at 320 °C, respectively. The crystal structure was determined from X-ray powder and single crystal data: K5H(CN)3, space group Im3m, a = 795.68(7) pm, Z = 2, R1 = 0.025, wR2 = 0.0438. In the solid K5H(CN2)3 contains K+ and CN22–, the anions exhibit D∞h symmetry. According to 1H and 13C solid state MAS-NMR investigations, temperature dependent impedance spectroscopy, and FTIR spectroscopy the protons are only loosely bound to the CN22– ions. The proton conductivity shows a sharp increase above 70 °C. |
