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Title: Reaction Pathway and Rovibrational Analysis of Aluminum Nitride Species as Potential Dust Grain Nucleation Agents
Abstract

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 formation pathway 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, AlNH6and AlNH4, along the reaction pathway for use as reference in possible laboratory or observational studies. Theν8bending frequency for AlNH6at 755.7 cm−1(13.23μm) presents a vibrational transition intensity of 515 km mol−1, more intense than the antisymmetric 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.

 
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NSF-PAR ID:
10491011
Author(s) / Creator(s):
;
Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
962
Issue:
2
ISSN:
0004-637X
Format(s):
Medium: X Size: Article No. 148
Size(s):
["Article No. 148"]
Sponsoring Org:
National Science Foundation
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