Computational Investigation into the Nature of Technetium-Technetium Bonding Within the Octachloroditechnetate (Tc2Cl82- / 3-) Anions
Poster Number
1
Format
Poster Presentation
Faculty Mentor Name
Anthony Dutoi
Faculty Mentor Department
Chemistry
Abstract/Artist Statement
Experimental investigations into the behavior of the technetium-technetium (Tc-Tc) bond within the octachloroditechnetate (Tc2Cl 2-/3-) family of anions suggest that the expected trend between bond order and bond length is not followed by the metal-metal bond within these anions. The simple model of bond order provides a qualitative relationship between bond length and bond order. As the bond order between two atoms increases, a decrease in the distance between the atoms is expected. However, high-level theoretical calculations found in the literature seem to support the experimental observation that the Tc-Tc bond is longer in the Tc2Cl82- anion, which has a higher Tc-Tc bond order, than in the Tc2Cl83-anion, whereas low-level calculations produced inconclusive results on the relationship between bond order and bond length for the Tc-Tc bond. In order to develop a better understanding of the behavior of the Tc-Tc bond, we first repeated several calculations using the lower-level theoretical models to produce graphs of energy versus Tc-Tc bond length. The most stable Tc-Tc bond length is that in which the total energy of the anion is at a minimum on the energy-bond length curve. Indeed, the Tc-Tc bond lengths extracted through this procedure provided mixed results as to which anion has the longer Tc-Tc bond. Now convinced that lower-level models are insufficient in modeling the behavior of metal-metal bonding within the Tc2Cl82-/3-anions, preliminary high-level calculations have been initiated. The high-level model found in the literature provided insights into the strengths of bonds between the Tc atoms, but did give any deeper explanation for the orbitals involved in the Tc-Tc bond. Although this level of theory is expected to be more reliable than the high-level models that we are currently using, these superior calculations are also more expensive and more difficult to work with.
Location
DeRosa University Center, Ballroom
Start Date
30-4-2016 1:30 AM
End Date
30-4-2016 3:30 PM
Computational Investigation into the Nature of Technetium-Technetium Bonding Within the Octachloroditechnetate (Tc2Cl82- / 3-) Anions
DeRosa University Center, Ballroom
Experimental investigations into the behavior of the technetium-technetium (Tc-Tc) bond within the octachloroditechnetate (Tc2Cl 2-/3-) family of anions suggest that the expected trend between bond order and bond length is not followed by the metal-metal bond within these anions. The simple model of bond order provides a qualitative relationship between bond length and bond order. As the bond order between two atoms increases, a decrease in the distance between the atoms is expected. However, high-level theoretical calculations found in the literature seem to support the experimental observation that the Tc-Tc bond is longer in the Tc2Cl82- anion, which has a higher Tc-Tc bond order, than in the Tc2Cl83-anion, whereas low-level calculations produced inconclusive results on the relationship between bond order and bond length for the Tc-Tc bond. In order to develop a better understanding of the behavior of the Tc-Tc bond, we first repeated several calculations using the lower-level theoretical models to produce graphs of energy versus Tc-Tc bond length. The most stable Tc-Tc bond length is that in which the total energy of the anion is at a minimum on the energy-bond length curve. Indeed, the Tc-Tc bond lengths extracted through this procedure provided mixed results as to which anion has the longer Tc-Tc bond. Now convinced that lower-level models are insufficient in modeling the behavior of metal-metal bonding within the Tc2Cl82-/3-anions, preliminary high-level calculations have been initiated. The high-level model found in the literature provided insights into the strengths of bonds between the Tc atoms, but did give any deeper explanation for the orbitals involved in the Tc-Tc bond. Although this level of theory is expected to be more reliable than the high-level models that we are currently using, these superior calculations are also more expensive and more difficult to work with.