## 3 Results and Discussion
### Computational Study
#### 3.3.5 Reactivity Descriptors
By reviewing the numerical and graphical data shown in Tables 7 and 8 and Figure 8, it is possible to conclude that there is a good agreement between the numerical values and the graphical representations produced by both ions and the complex. When inspecting the numerical component, it is clear that the reactive sites predicted by the Fukui functions are accurate in all cases. This discovery is supported by considering the graphical representations of the Fukui functions and numerical results of the dual descriptor, which, despite being extended over the atoms within the molecules, are more compact than the other Fukui function descriptors. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Compounds** & \(\epsilon H\) & \(\epsilon L\) & \(\epsilon L\)-\(\epsilon H\) & \(\chi\) & \(\mu\) & \(\eta\) & \(S\) & \(\omega\) \\ \hline Tetraphenylborate & \(-\)0.284 & \(-\)0.145 & 0.139 & 0.214 & \(-\)0.214 & 0.07 & 7.191 & 0.165 \\ \hline clonidine & \(-\)0.111 & 0.056 & 0.166 & 0.028 & \(-\)0.028 & 0.083 & 6.012 & 0.002 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Calculated \(\epsilon\epsilon\mathrm{HOMO}\), \(\epsilon\mathrm{LUMO}\), energy band gap (\(\epsilon\mathrm{LUMO}\)- \(\epsilon\mathrm{HOMO}\)), chemical potential (\(\mu\)), electronegativity (\(\chi\)), global hardness (\(\eta\)), global softness (\(S\)), and global electrophilicity index (\(\omega\)) for tetrahydrofuran and its derivatives at B3 LYP/6-311 G (d, p) level. Figure 8: Graphical representation of the Fukui descriptors. We provide Fukui functions, local softness values, and local electrophilicity indices for various atomic locations in clonidine and tetraphenylborate, as well as Figure 8. The greatest value for local nucleophilic reactivity descriptors \(\mathrm{f_{-}^{-}}\), \(\mathrm{s_{-}^{-}}\), and \(\mathrm{\omega_{k}^{-}}\) was at two phenyl groups in tetraphenylborate that were far away from the clonidine molecule in the complex, and that site is more susceptible to electrophilic assault. The largest value for local electrophilic reactivity descriptors \(\mathrm{f_{k}^{+}}\), \(\mathrm{s_{+}^{+}}\), and \(\mathrm{\omega_{k}^{+}}\) was shown in the clonidine molecule in a complex whose site is more sensitive to nucleophilic attack, as seen in Tables 7-9, which forms the bond between two compounds. Molecular Electrostatic Potential (MESP)  
When tetraphenylborate and clonidine are utilized as anion and cation molecules, respectively, molecular electrostatic interaction between cation and anion molecules is thought to be one of the most fundamental driving forces for the formation of inclusion complexes. DFT calculations of the electrostatic potential for the cation and anion molecules were conducted to test the above idea. Figure 9A,G illustrates the outcomes. As a map of electrostatic potential on an isoelectronic surface, the positive electrostatic potentials of amino groups are centered around the hydrogen atoms, shown in Figure 9A,C, while the negative electrostatic potentials are localized on nitrogen and chlorine atoms in clonidine molecules, shown in Figure 9B,C. The negative potential is concentrated on the carbon class boron section of the tetraphenylborate molecule. The anion of the tetraphenylborate molecule has no positive potential (Figure 9E), but the positive charge is found in the para carbon of the phenyl groups in the neutral atom as shown in Figure 9F. It is worth noting that the positive potentials of clonidine's amino hydrogen match the negative potentials on the carbon of phenyl groups that connect with the boron atom on the tetraphenylborate molecule, and the negative potential of the tetraphenylborate molecule matches the positive potentials observed in the clonidine molecule in the complexes shown in Figure 7G. The charge distribution in clonidine and tetraphenylborate appears to be a primary driving mechanism for the creation of electrostatic attraction complexes. Figure 9: _Cont._