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The lack of observational data for the AlO molecule in the mesosphere/lower thermosphere may be due to ablated aluminum reacting quickly to form other species. Previously proposed reaction pathways show that aluminum could be ablated in the atmosphere from meteoritic activity, but there currently exist very limited spectroscopic data on the intermediates in these reactions, limiting the possible detection of said molecules. As such, rovibrational spectroscopic data are computed herein using quartic force field methodology at four different levels of theory for the neutral intermediates AlCO3, OAlO2, and HOAlO2. Each molecule exhibits multiple vibrational modes with large vibrational transition intensities. For instance, the C–O stretch (ν1) in AlCO3 has a harmonic intensity of 536 km mol−1, the Al–O stretch (ν2) in OAlO2 has an intensity of 678 km mol−1, and the out-of-plane torsion (ν9) in HOAlO2 has an intensity of 158 km mol−1. All three molecules have exceptionally large dipole moments of 6.27, 4.21, and 5.04 D, respectively. These properties indicate that all three molecules are good candidates for potential atmospheric observation utilizing vibrational and/or rotational spectroscopic techniques. [ABSTRACT FROM AUTHOR]

A series of five Re(pyNHC‐aryl)(CO)3X complexes varying the "X" ligand where pyNHC is a pyridyl N‐heterocyclic carbene have been synthesized and characterized through NMR, UV/Vis absorption spectroscopy, IR, mass spectrometry, time‐correlated single photon counting, computational analysis, and cyclic voltammetry. The photocatalytic reduction of CO2 to CO in the presence of a sacrificial electron donor with these complexes is evaluated using a simulated solar spectrum (AM 1.5G). Comparison of Br and CH3CN as the "X" ligand shows the same photocatalytic activity (both 32 TON). The use of Cl, NCS and P(OEt)3 "X" ligands all led to diminished reactivity with as little as 2 TON for the P(OEt)3 complex. These results were rationalized through computational analysis of "X" dissociation and excited‐state lifetime measurements. These results highlight the importance of the "X" ligand selection on catalysis with Re‐pyNHC complexes. [ABSTRACT FROM AUTHOR]

B The Cover Feature b shows the impact of an "X" ligand on the performance of photocatalysts reducing CO SB 2 sb to CO via a series of pyridyl N-heterocyclic carbene rhenium tricarbonyl complexes. These catalysts show impressive rate and durability in this reaction upon judicious "X" ligand selection. These catalysts show impressive rate and durability in this reaction upon judicious "X" ligand selection. [Extracted from the article]