Observation and assignment ofD7,°7, andS7Rydberg series of molybdenum atoms by multiphoton dissociation and ionization spectroscopy of organometallic molecules

The multiphoton ionization spectra of several arene molybdenum tricarbonyls have been measured in the region 350–420 nm. These spectra exhibit allowed, two-photon resonant ns ${}_{}{}^7{}_{}{}^{}$ ${\mathit{S}}_3$ and nd ${}_{}{}^7{}_{}{}^{}$ ${\mathit{D}}_{\mathit{J}}$ Rydberg series of neutral bare molybdenum atoms. Furthermore, the electric field inherent to the multiphoton ionization experiment also permits observation of the nominally forbidden np ${}_{}{}^7{}_{}{}^{}$P${\mathrm{°}}_{\mathit{J}}$ Rydberg series. A nonlinear least-squares regression of the Rydberg equation was used to obtain an improved ionization potential of molybdenum and the quantum defects of the three series.