2024/01/11 by C. Zachary Palmer, Palmer, C. Zachary, Ryan C. Fortenberry +1
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #Atmospheric Ozone and Climate #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.2401.06288
openalex publication_date 2024/01/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A dust nucleating agent may be present in interstellar or circumstellar media that has gone seemingly undetected and unstudied for decades. Some analyses of the Murchison CM2 meteorite suggest that at least some of the aluminum present within condensed as aluminum nitrides instead of the long studied, but heretofore undetected suite of aluminum oxides. The present theoretical study utilizes explicitly correlated coupled cluster theory and density functional theory to provide a pathway of formation from alane (AlH3) and ammonia to the cyclic structure, Al2N2H4 which has the proper Al/N ratio expected of bulk aluminum nitrides. Novel rovibrational spectroscopic constants are computed for alane and the first two formed structures, AlNH6 and AlNH4, along the reaction pathway for use as reference in possible laboratory or observational studies. The ν8 bending frequency for AlNH6 at 755.7 cm-1 (13.23 μm) presents a vibrational transition intensity of 515 km mol-1, slightly more intense than the anti-symmetric C-O stretch of carbon dioxide, and contains a dipole moment of 5.40 D, which is ∼ 3 × larger than that of water. Thus, the present reaction pathway and rovibrational spectroscopic analysis may potentially assist in the astrophysical detection of novel, inorganic species which may be indicative of larger dust grain nucleation.