Document Type
Honors Thesis
Publication Date
4-8-2021
Abstract
Four constitutional isomers{ dibridged, monobridged, vinylidene-like, and trans{ of group 13 metal dihydrides have been reviewed and studied by theoretical methods. Equilibirum structures, relative enthalpies, and vibrational spectroscopic information is presented for isomers of Al2H2, Ga2H2, In2H2, and Tl2H2. Properties of the isomers of Al2H2 and Ga2H2 were obtained from previous studies.1{3 Properties of In2H2 and Tl2H2 were calculated using rigorous ab initio theory, and the results are presented. All four isomers were found as equilibrium structures for In2H2, and all but trans were found for Tl2H2, where this isomer is a transition state. Geometric trends of the bridging isomers suggests ionic-like bonding is present, whereas trends in the vinylidene-like and trans isomers predict bonds with more covalent character. Relative enthalpies of the Al2H2 and Ga2H2 isomers show the dibridged as the most stable, then vinylidene-like, monobridged, and trans, the least stable. With heavier group 13 atoms, In2H2 and Tl2H2 were found to have relative enthalpies in a di erent ordering of stability: dibridged, the most stable, then monobridged, vinylidenelike,and trans. This increased stability of bridging isomers in heavy metal compounds is due to a stronger dipole in the metal-hydrogen bonds. The instability of the vinylidene-like and trans isomers is due to a weakening of the metal-metal bonds in the dimetal dihydrides.
Recommended Citation
Sargent, Caroline, "Theoretical Investigation of In2H2 and Tl2H2 and their Relationship to other Group 13 Metal Dihydrides" (2021). Student Scholarship. 46.
https://digitalcommons.wofford.edu/studentpubs/46