## 3 Results and Discussion
### Computational Study
#### 3.3.5 Reactivity Descriptors  
Global Reactivity Descriptors  
Global reactivity descriptor for tetraphenylborate-clonidine complex parameters are shown in Table 6. Chemical reactivity changes with the structural configuration of molecules according to various characteristics. Clonidine has a lower chemical hardness (softness) value than the tetraphenylborate complex. Clonidine reacts as a cation, while tetraphenylborate reacts as an anion. As shown in Table 6, the tetraphenylborate structure has a greater electronegativity and electrophilicity index than clonidine. The electrophilicity  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**BCP** & **Bond** & \(\rho\)**(**r) (a.u. )** & **K(r) (a.u. )** & **V(r) (a.u. )** & **H(r) (a.u. )** & \(\
abla^{2}\)**(r)** & **G(r) (a.u. )** & 1V(r) /G(r) \\ \hline
147 & Cl(19)-H(54) \(\cdots\  
of various chemical substances and reaction rates in biological systems were discovered to be related. The Fukui function (FF) is a technique for analyzing chemical reactions that offers information on the local site reactivity inside the molecule. These numbers refer to qualitative reactivity descriptors for various atoms in the molecule. The B3 LYP/6-311 G (d, p) level of theory was used to create Fukui functions for electrophilic and nucleophilic attacks. The following equation was used to determine local Fukui functions (\(\mathrm{f}_{\mathrm{k}}^{+}\), \(\mathrm{f}_{\mathrm{k}}^{-}\)), and the dual descriptor, local softness values (\(\mathrm{s}_{\mathrm{k}}^{+}\), \(\mathrm{s}_{\mathrm{k}}^{-}\)), and local electrophilicity indices (\(\mathrm{\omega}_{\mathrm{k}}^{+}\), \(\mathrm{\omega}_{\mathrm{k}}^{-}\)) using Mulliken atomic charges of cationic and anionic states:  
\[\mathrm{for\ nucleophilic\ attack:\ }\mathrm{f}_{\mathrm{k}}^{+}=[\mathrm{q}( \mathrm{N}+1)-\mathrm{q}(\mathrm{N})], \tag{11}\] \[\mathrm{for\ electrophilic\ attack:\ }\mathrm{f}_{\mathrm{k}}^{-}=[ \mathrm{q}(\mathrm{N})-\mathrm{q}(\mathrm{N}-1)],\] (12) \[\mathrm{for\ radical\ attack:\ }\mathrm{f}_{\mathrm{k}}^{0}=[ \mathrm{q}(\mathrm{N}+1)-\mathrm{q}(\mathrm{N}-1)], \tag{13}\]  
However, there are situations in which the results of both descriptions overlap, making it impossible to derive accurate conclusions. Rather than that, the dual descriptor Df(r) or DD can unambiguously characterize nucleophilic and electrophilic locations in a molecule. Thus, a graphical representation of the DD for both ions and complex is provided in Figure 8, clearly indicating the regions within the molecules where Df > 0 and Df < 0 occur, allowing for a better comprehension of these molecules' local chemical reactions. Other local reactivity descriptors are the local softness values and electrophilicity indices, which were calculated using the following equation. \[\mathrm{s}_{\mathrm{k}}^{+}=\mathrm{S}\times\mathrm{f}_{\mathrm{k}}^{+}\text{, }\mathrm{s}_{\mathrm{k}}^{-}=\mathrm{S}\times\mathrm{f}_{\mathrm{k}}^{-}, \tag{14}\]  
\[\mathrm{\omega}_{\mathrm{k}}^{+}=\mathrm{\omega}\times\mathrm{f}_{\mathrm{k}}^ {+}\text{, }\mathrm{\omega}_{\mathrm{k}}^{-}=\mathrm{\omega}\times\mathrm{f}_{\mathrm{k}}^ {-}, \tag{15}\]  
where + and \(-\) signs show nucleophilic and electrophilic attacks, respectively. To compare the results obtained from the two ions and complex, the predictions for the specific reaction sites derived from the electrophilic and nucleophilic Fukui functions analyses for each ion were collated into two tables along with the local softness and electrophilicity indices. For completeness, the radical Fukui function \(\mathrm{f}_{\mathrm{k}}^{0}\) was provided, which can be thought of as an average of \(\mathrm{f}_{\mathrm{k}}^{+}\), and \(\mathrm{f}_{\mathrm{k}}^{-}\) and denotes the most suitable locations for a radical attack. In addition to the tables, a graphical depiction of these descriptors is given in the form of a series of figures, such as the comparison of the results obtained for both ions and their complex under the accurate investigations.