Assignment and vibronic analysis of the 5D0 → 7F2 transition of Eu3+ in hexanitritolanthanate systems

► A series of lanthanide hexanitrito complexes have been prepared. ► 10 K, 100 K luminescence, 300 K FT-IR and FT-Raman spectra have been recorded. ► The assignment of vibronic structure of the 5D0 → 7F0, 7F2 transitions in the electronic spectra of M2M′Eu(NO2)6 has been made. ► The derived energy levels indicate a weak crystal field in these systems.