Highly excited quasistable states of neutral CO lying up to the double-ionization-energy level

Synchrotron radiation induced photoionization and photodissociation of carbon monoxide in the 14–35 eV region

“…5 and those given in the original experiments [16] is satisfactory, while there are several substantial disagreements with the experiments [18]. In particular, it may be questioned how a number of n > 4 progressions could be discernible since the intensities drop rapidly with increasing n (roughly as 1/n3).…”

“…5) down to about 630 where a complex line structure starts which we attribute to Rydberg series converging to the upper doubly excited CO + states D, C and E. These series, originally discovered in photoabsorption experiments [16] were tentatively classified using level energies of the associated CO + states obtained from photoelectron spectroscopy [t7]. These series were also observed as weak structures in O-fragment spectra formed by synchrotron radiation [18]. The analysis given in Fig.…”

“…3.1.3. As pointed out in [18] studies of ion-pairs could be a more sensitive probe of Rydberg progressions since the underlying ionization continua are weak or absent. This is apparent for the C+/CO spectrum displayed in Fig.…”

“…The C+/CO mass spectrum has been studied earlier [19,20] but no analysis was reported. The associated O-/CO spectrum has also been measured and analyzed [18] as discussed in Sect. 3.1.3.…”

State-Specific Enhancement ofCl+andCl−Desorption forChen1, Lu2 2001Phys. Rev. Lett.

“…It has been shown that there exists some highly excited states near or above the double ionization threshold energies on gas-phase molecules, such as SO 2 and CO [10,11]. However, due to adsorbate-substrate and adsorbateadsorbate interaction for molecular adsorbates on surfaces, these highly excited states, such as doubly excited Rydberg states, may be quenched or disappeared in the solid phase.…”