Nitrogen K-shell excitations in gold(I) and silver(I) dicyanide KM(CN)2 (M=Au, Ag) by XANES spectroscopy

Nitrogen K-shell photoabsorption spectra of KCN, KAu(CN)2 and KAg(CN)2 were recorded using the synchrotron based X-ray absorption fine structure (XANES) spectroscopy. All types of transitions commonly appearing in the near edge region, i.e., K→π* transitions, Rydberg transitions, double excitations and shape resonances, are observed in the nitrogen XANES spectra of KCN, KAu(CN)2 and KAg(CN)2. The results show that there is a blue shift of the lowest energy transition (K→π* resonance) after CN− forms [Au(CN)2−]n and [Ag(CN)2−]n complexes.