Electronic Spectrum of AgNH₃ Complex

The electronic spectrum of the silver-ammonia 1:1 complex AgNH₃ has been observed for the first time. The complex was formed using laser ablation and cooled in a free jet expansion, and its spectrum was observed through resonantly enhanced multiphoton ionization (REMPI) method. The origin of the band system of AgNH₃ located at 467 nm is red-shifted from the corresponding Ag 5p²S_1/2 - 5s²S transition by 8142 cm^-1, indicating a significant stabilization upon electronic excitation. Vibrational frequencies of the intermolecular stretching and bending mode in the excited state were determined to be 378 cm^-1 and 185cm^-1, respectively.