Anion Photoelectron Spectroscopy of C₃N⁻ and C₅N⁻

Abstract

Anion photoelectron spectroscopy of C 3 N -and C 5 N -is performed using slow electron velocity-map imaging (SEVI) and field-free time-of-flight (TOF), respectively. The SEVI spectrum exhibits well-resolved vibrational transitions from the linear C 3 N -ground state to the corresponding C 3 N ground state. The TOF spectrum comprises transitions arising from the linear C 5 N -ground state to the corresponding neutral ground and excited states. This study yields the adiabatic electron affinities of C 3 N and C 5 N to be 4.305 ( 0.001 and 4.45 ( 0.03 eV, respectively, and a term value of 560 ( 120 cm -1 for the à 2 Π state of C 5 N. Vibrational frequencies for the degenerate cis and trans bending modes of C 3 N -are also extracted.

Formation ofCN−,C3N

“…2 and 3. The C 3 N electron affinity of 4.6 eV and its dipole moment, d=3.0 D, obtained in the present study agree reasonably well with the published data EA=4.305 eV [26] and d=2.864 D [16]. Similarly to CN, in continuum-state calculations, the target molecule was represented using CASCI build on HF orbitals.…”

“…The electronic structure of C 3 N and C 3 N − was studied in several theoretical studies (see, for example, Ref. [26] and references therein). Collision of C 3 N with electrons and C 3 N − resonances were also studied in Ref.…”

Infrared Photodissociation Spectroscopy of C2n+1N− Anions with n = 1 – 5

“…The latter results are supported by the SEVI experiments of Garand et al and Yen et al [21,22]. Botschwina et al performed a detailed theoretical analysis of the C 2n+1 N − ( = 1-6) anions using coupled cluster theory combined with large basis sets and predicted, among other spectroscopic constants, their equilibrium structures as well as harmonic ( = 1-6) and anharmonic ( = 1-3) vibrational frequencies [18,24].…”

“…The global minimum-energy structure of bare C 3 N − , as well as those of larger [24] is linear and N-terminated [18,22]. For the messenger-tagged C 3 N − anion, D 2 binds collinear to either the terminal Catom (C-site) or N-atom (N-site).…”

“…In their matrix studies, which mainly focused on the electronic transitions of C 2n+1 N − ( = 2-6) anions, Grutter et al [19] also reported the IR absorption spectra of the smaller anions and found evidence for a few IR transitions for C 5 N − , C 7 N − and C 9 N − . Garand et al and Yen et al [21,22] investigated the anion photoelectron spectra of the C n N − ( = 2-6) clusters using slow electron velocity-map imaging (SEVI) and determined adiabatic electron affinities for C 3 N and C 5 N, as well as vibrational frequencies for the fundamentals of the degenerate cis (538 cm −1 ) and trans (208 cm states for the anions with odd and even number of carbon atoms, respectively [23].…”