About alkali metal dicyanamides: syntheses, single-crystal structure determination, DSC/TG and vibrational spectra of KCs[N(CN)2]2 and NaRb2[N(CN)2]3 · H2O

Abstract

Abstract Transparent colorless crystals of KCs[N(CN)2]2 and NaRb2[N(CN)2]3 · H2O were obtained by blending aqueous solutions of Na[N(CN)2] and RbF or KF, respectively. After evaporation of the water, the remaining solid was extracted with absolute ethanol and the solvent was allowed to evaporate at r. t.. KCs[N(CN)2]2 crystallizes in the space group C2/c (no. 15) with the cell parameters a = 1382.7(2), b = 998.1(1) and c = 1455.4(2) pm, and β = 118.085(4) °. The structure of NaRb2[N(CN)2]3 · H2O is exhibiting the space group P63/m (no. 176) with the cell parameters a = 705.98(7) and c = 1462.89(12) pm. Single-crystalline α-K[N(CN)2] was obtained while attempting to synthesize ‘NaK2[N(CN)2]3’, corroborating the results of previous X-ray powder diffraction experiments. Vibrational spectra and DSC/TGA analyses complete our results.