A Computational Determination of the Lowest Energy Electronic and Geometric States of First Row Transition Metal Dioxygen Dications

<table class="table-group" id="tab1"><tr><td><table class="table"><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr class="thead"><td align="left"> </td><td align="center">Spin state</td><td align="center">O–O</td><td align="center">TM–O<sub>2</sub></td><td align="center"><svg height="8.6750002" id="M29" style="vertical-align:-0.0pt" version="1.1" viewbox="0 0 10.1 8.6750002" width="10.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,8.613)"><path d="M556 0h-481l-12.5 19l-12.5 19l312 465q8 -5 23.5 -15.5t23.5 -15.5l-284 -422h431v-50z" id="x2220"></path></g>
</svg>TMOO</td></tr><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr><td align="left"><svg height="14.85" id="M30" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>ScO<sub>2</sub><svg height="14.85" id="M31" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Doublet</td><td align="center">130.0</td><td align="center">195.4</td><td align="center">70.6</td></tr><tr><td align="left"><svg height="14.85" id="M32" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>TiO<sub>2</sub><svg height="14.85" id="M33" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Triplet</td><td align="center">124.2</td><td align="center">176.5</td><td align="center">180.0</td></tr><tr><td align="left"><svg height="14.85" id="M34" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>VO<sub>2</sub><svg height="14.85" id="M35" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Doublet</td><td align="center">121.0</td><td align="center">197.1</td><td align="center">180.0</td></tr><tr><td align="left"><svg height="14.85" id="M36" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>CrO<sub>2</sub><svg height="14.85" id="M37" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Triplet</td><td align="center">120.9</td><td align="center">193.4</td><td align="center">180.0</td></tr><tr><td align="left"><svg height="14.85" id="M38" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>MnO<sub>2</sub><svg height="14.85" id="M39" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Quartet</td><td align="center">120.7</td><td align="center">200.6</td><td align="center">175.4</td></tr><tr><td align="left"><svg height="14.85" id="M40" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>FeO<sub>2</sub><svg height="14.85" id="M41" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Triplet</td><td align="center">120.2</td><td align="center">196.3</td><td align="center">161.9</td></tr><tr><td align="left"><svg height="14.85" id="M42" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>CoO<sub>2</sub><svg height="14.85" id="M43" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Doublet</td><td align="center">120.0</td><td align="center">198.3</td><td align="center">144.4</td></tr><tr><td align="left"><svg height="14.85" id="M44" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>NiO<sub>2</sub><svg height="14.85" id="M45" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Singlet</td><td align="center">116.3</td><td align="center">182.2</td><td align="center">127.7</td></tr><tr><td align="left"><svg height="14.85" id="M46" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>CuO<sub>2</sub><svg height="14.85" id="M47" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Quartet</td><td align="center">124.4</td><td align="center">196.7</td><td align="center">137.5</td></tr><tr><td align="left"><svg height="14.85" id="M48" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M290 -163h-170v866h170v-28q-79 -7 -94 -19.5t-15 -72.5v-627q0 -59 14.5 -71.5t94.5 -19.5v-28z" id="x5B"></path></g>
</svg>ZnO<sub>2</sub><svg height="14.85" id="M49" style="vertical-align:-2.22495pt" version="1.1" viewbox="0 0 5.9875002 14.85" width="5.9875002" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.012)"><path d="M226 -163h-170v27q79 7 94 20t15 73v627q0 59 -15 72t-94 20v27h170v-866z" id="x5D"></path></g>
</svg><sup>2+</sup></td><td align="center">Triplet </td><td align="center">118.1</td><td align="center">232.2</td><td align="center">126.0</td></tr><tr class="table-tr"><td colspan="5"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

Lowest energy spin states and geometric parameters of [TM–O<sub>2</sub>]<sup>2+</sup> molecules.  Bond lengths in pm and bond angles in degree. 

Journal of Theoretical Chemistry

tab1

Table 1

Table 1: A Computational Determination of the Lowest Energy Electronic and Geometric States of First Row Transition Metal Dioxygen Dications 