Synthesis, crystal structure, and solid state MAS-NMR spectroscopic investigation of K5H(CN2)(3) [German]

摘要

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 degrees 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-infinity h symmetry. According to H-1 and C-13 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 degrees C. [References: 18]