Synthesis and Stability of Ammonium Selenocyanate [NH4][SeCN] and Its Reactivity toward Ag[SeCN]

We present the first crystallographicstudy of [NH4][SeCN] and Ag[SeCN], where the former isa sensitive compound, andthe latter is stable under a variety of conditions. Additionally,we explored their reactivity toward one another, leading to [NH4][Ag(SeCN)(2)] and [NH4](3)[Ag(SeCN)(4)]. [NH4][SeCN] and Ag[SeCN] were synthesizedby salt metathesisstarting from the respective chlorides and K[SeCN]. Both productswere fully characterized by single-crystal and powder X-ray diffraction,differential scanning calorimetry-thermogravimetric analysis (DSC-TGA),and solid-state IR and Raman spectroscopy. Quantum-mechanical calculationsallowed for detailed assignment and interpretation of vibrationalspectra. For dissolved [NH4][SeCN], nuclear magnetic resonancespectra were collected. High-temperature powder X-ray diffraction(HT-PXRD) allowed for the analysis of the thermal behavior of solid[NH4][SeCN]. Furthermore, the reaction of [NH4][SeCN] with Ag[SeCN] leads to the formation of the ternary salts[NH4][Ag(SeCN)(2)] and [NH4](3)[Ag(SeCN)(4)]. The structures of the latter were determinedfrom single-crystal X-ray diffraction (SC-XRD) data, and bulk analysiswas performed by Rietveld refinement, Raman spectroscopy, and elementalanalysis.

Automated summary

The crystallographic study of [NH4][SeCN] and Ag[SeCN] is presented for the first time. [NH4][SeCN] is a sensitive compound, while Ag[SeCN] is stable under various conditions. The reactivity between them resulted in the formation of [NH4][Ag(SeCN)(2)] and [NH4](3)[Ag(SeCN)(4)]. The characterization of both compounds was performed using various techniques such as single-crystal and powder X-ray diffraction, thermal analysis, and spectroscopy.