We investigate the Zeeman effect in the 0-0 band of the e 6 Π –a 6 Δ system of FeH, producing the molecule at near-ambient temperatures and recording Doppler-limited laser excitation spectra, using selective detection. We provide a set of effective Landé factors for the three lowest spin components of both states, extracted from the analysis of partially-resolved Zeeman patterns seen in magnetic flux denisities of 0.4 –0.7 T. Landé factors in the upper state show strong variations with parity, unlike the lower state level, which is close to having a single electronic configuration. Landé factors for two Fe(I) lines at 18611.635 cm − 1 and 19573.056 cm − 1 , recorded for magnetic flux density calibration, have been refined in the process. • Laser excitation spectra were collected from selected e 6 Π - a 6 Δ transitions of FeH in the presence of an applied magnetic flux density. • Landé factors for the associated rotational levels were obtained. • A perturbation in one spectrum was tentatively attributed to a Zeeman-induced interaction between the a 6 Δ 9/2 v=0 J=6.5 and X 4 Δ 7/2 v=1 J=7.5 levels. • Landé factors for three levels of atomic iron were improved.

The studies of spectroscopy, reactivity, and photochemistry of CN-substituted aromatic molecules have acquired particular relevance since their detection in TMC-1 in 2018. In this context, the REMPI spectroscopy of 1-cyanonaphthalene (1CNN) and its complexes with one (1CNN-W) and two (1CNN-W 2 ) water molecules (W = H 2 O) was recorded and compared with theoretical calculations at the CAM-B3LYP/aug-cc-pVDZ level, validating the theoretical method and justifying its use in predicting some properties of the cat ionic species in their ground and excited electronic states. The adiabatic ionization potential (IP ad ) for 1CNN monomer was experimentally determined for the first time (8.432 eV) and agrees to well within 1% with the theoretical value (8.417 eV). Ionization thresholds for 1CNN-W and 1CNN-W 2 complexes, as well as the water evaporation threshold in the cationic state of the latter complex, were also determined experimentally and were found to agree with the theoretical results to within 1% . Based on the available data, it is tentatively predicted that once 1CNN forms aggregates with ≥1 H 2 O molecules, these complexes will be ionized by Ly-α irradiation, but they will be stable in their cationic state. • 1st experimental determination of 1Cyanonaphthalene adiabatic ionization potential. • Ionization thresholds for 1Cyanonaphthalene-water complexes are reported. • Evaporation threshold in the cationic state of the 1:2 complex was determined. • It is predicted that 1CNN-H 2 O n will be stable in their cationic state under Ly-α.