diff --git a/Figure7.eps b/Figure7.eps index bea4f6e..58af8db 100644 Binary files a/Figure7.eps and b/Figure7.eps differ diff --git a/TODO.md b/TODO.md index d290e2b..1381b98 100644 --- a/TODO.md +++ b/TODO.md @@ -38,6 +38,6 @@ For v3.0 (to be submitted): - [x] Update SI (!!) - [x] Address last comments -For v4.0: +For v4.0 (first round of comments from reviewers): - [ ] Metadata for all column of CSVs diff --git a/im/mols.cdxml b/im/mols.cdxml index 0f07298..e4e3df6 100644 --- a/im/mols.cdxml +++ b/im/mols.cdxml @@ -4,8 +4,8 @@ CreationProgram="ChemDraw 22.2.0.3300" Name="mols.cdxml" BoundingBox="21.27 4.75 516.43 664.55" - WindowPosition="-1073741824 1073741824" - WindowSize="-2147483648 0" + WindowPosition="1073741824 -1073741824" + WindowSize="1073741824 -1073741824" FractionalWidths="yes" InterpretChemically="yes" ShowAtomQuery="yes" @@ -84,7 +84,7 @@ NONORNOOOHCOOHNOR2OOHCOOHR3NOONONORNOOOHCOOHOOHCOOHONONORNORNOOOHCOOHNOOOHCOOHNOR2R1R3R4NORNORNORNOR1R2R3R4R5R612 R=H 6 R=OH -3 R=COOH 11 R=NH3+ -4 R=NH2 61 R=Br -5 R=OMe2 R=-H 6 R=-OH +3 R=-COOH 11 R=-NH3+ +4 R=-NH2 61 R=-Br +5 R=-OMe78 R2=H R3=H -9 R2=COOH R3=H -10 R2=H R3=COOH8 R2=-H R3=-H +9 R2=-COOH R3=-H +10 R2=-H R3=-COOH1314 R=H 18 R=OH -15 R=COOH 21 R=NH3+ -16 R=NH2 56 R=CONH2 -17 R=OMe 57 R=CH2NH214 R=-H 18 R=-OH +15 R=-COOH 21 R=-NH3+ +16 R=-NH2 56 R=-CONH2 +17 R=-OMe 57 R=-CH2NH2202258 R=CONH2 -59 R=CH2NH258 R=-CONH2 +59 R=-CH2NH223 R=H 27 R=OH -24 R=COOH 34 R=CH2NH2 -25 R=NH2 35 R=NH3+ -26 R=OMe 60 R=Br23 R=-H 27 R=-OH +24 R=-COOH 34 R=-CH2NH2 +25 R=-NH2 35 R=-NH3+ +26 R=-OMe 60 R=-Br192829 R1=COOH R2=R3=R4=H -30 R1=R4=COOH R2=R3=H -31 R1=R3=COOH R2=R4=H -32 R1=R2=COOH R3=R4=H -33 R2=R3=COOH R1=R4=H29 R1=-COOH R2=R3=R4=-H +30 R1=R4=-COOH R2=R3=-H +31 R1=R3=-COOH R2=R4=-H +32 R1=R2=-COOH R3=R4=-H +33 R2=R3=-COOH R1=R4=-H36 R=H -37 R=COOH -49 R=NH2 -52 R=NO236 R=-H +37 R=-COOH +49 R=-NH2 +52 R=-NO238 R=COOH -50 R=NH2 -53 R=NO238 R=-COOH +50 R=-NH2 +53 R=-NO239 R=COOH -51 R=NH2 -54 R=NO239 R=-COOH +51 R=-NH2 +54 R=-NO240 R1=R2=COOH R3=R4=R5=R6=H -41 R1=R3=COOH R2=R4=R5=R6=H -42 R1=R4=COOH R2=R3=R5=R6=H -43 R1=R5=COOH R2=R3=R4=R6=H -44 R1=R6=COOH R2=R3=R4=R5=H -45 R2=R3=COOH R1=R4=R5=R6=H -46 R2=R4=COOH R1=R3=R5=R6=H -47 R2=R5=COOH R1=R3=R4=R6=H -48 R3=R4=COOH R1=R2=R5=R6=H -55 R3=R4=NO2 R1=R2=R5=R6=H40 R1=R2=-COOH R3=R4=R5=R6=-H +41 R1=R3=-COOH R2=R4=R5=R6=-H +42 R1=R4=-COOH R2=R3=R5=R6=-H +43 R1=R5=-COOH R2=R3=R4=R6=-H +44 R1=R6=-COOH R2=R3=R4=R5=-H +45 R2=R3=-COOH R1=R4=R5=R6=-H +46 R2=R4=-COOH R1=R3=R5=R6=-H +47 R2=R5=-COOH R1=R3=R4=R6=-H +48 R3=R4=-COOH R1=R2=R5=R6=-H +55 R3=R4=-NO2 R1=R2=R5=R6=-H \SI{5}{\elementarycharge\bohr\squared}$ for most members of IIO or APO). Additionally, modifications due to donor/acceptor substituents are linked to changes in the dipole moment. For example, aromatic compounds with \ce{NH2} as a substituent (\textit{e.g.}, \textbf{51}) are characterized by $\mu_{x} < 0$, which increases for compounds with \ce{COOH} (\textit{e.g.}, \textbf{39}) or \ce{NO2} (\textit{e.g.}, \textbf{54}). Furthermore, members of P5O generally present a smaller value of $U_q$ than P6O (\textit{e.g.}, \textbf{17} versus \textbf{5}), which correlates with the increase in oxidation potential observed between these two families. The same trend is observed between APO and IIO. +Though the correlation is poorer for reduction than for oxidation (probably because the electron delocalization means that the nitrogen atom is not the atom that should be used to define the origin in that case), this model helps explaining the general trends. For instance, the increase in oxidation (and reduction) potential for aromatic compounds correlates with an increase in quadrupole moment ($Q_{xx} > \SI{5}{\elementarycharge\bohr\squared}$ for most members of IIO or APO). Additionally, modifications due to donor/acceptor substituents are linked to changes in the dipole moment. For example, aromatic compounds with \ce{-NH2} as a substituent (\textit{e.g.}, \textbf{51}) are characterized by $\mu_{x} < 0$, which increases for compounds with \ce{-COOH} (\textit{e.g.}, \textbf{39}) or \ce{-NO2} (\textit{e.g.}, \textbf{54}). Furthermore, members of P5O generally present a smaller value of $U_q$ than P6O (\textit{e.g.}, \textbf{17} versus \textbf{5}), which correlates with the increase in oxidation potential observed between these two families. The same trend is observed between APO and IIO. This model also accounts for some effects due to the position of the substituent (see, e.g., \textbf{49}-\textbf{51}), which was not the case with the original model by Zhang and co-workers (resulting in weak correlations, $R^2 \leq 0.3$). Finally, although this model is not directly applicable to positively charged substituents (\textbf{11}, \textbf{21}, and \textbf{35}), for which the dipole and higher multipole moments are ill-defined, the only term of Eq.~\eqref{eq:Er} would be $(q\,q')/r$ (where $q'$ is the charge of the substituent), resulting in a destabilizing interaction with \ce{N+} and \ce{N^.}, while stabilizing \ce{N-} (Fig.~\ref{fig:dipole}), which correlates well with the increase in oxidation and reduction potentials for these compounds. @@ -540,13 +540,13 @@ \subsection{Impact of the electrolytes} \label{sec:elect} \label{fig:Kx2} \end{figure} -As expected, the equilibrium constants are smaller by about four orders of magnitude ($\Delta G^\star_{cplx} \sim \SI{40}{\kilo\joule\per\mole}$) than those previously discussed. In water, the general order is $K_{22} \leq K_{02} < K_{12}$. However, for many compounds in the IIO and APO families, $K_{02}$ is larger than $K_{22}$, which is attributed to the interaction between the \ce{NMe4+} cation and the aromatic moiety present in these compounds. In acetonitrile, the \ce{NAC^-} complexes are again more stable than the others, consistently with previous observations \cite{wylieImprovedPerformanceAllOrganic2019a}. Thus, the dielectric constant significantly impacts the equilibrium constants of these ion-triplets. This is further confirmed by the observation that the stabilization of \ce{N^.AC} is less pronounced in this study than in Ref.~\citenum{wylieImprovedPerformanceAllOrganic2019a}, which employed a solvent with an even lower dielectric constant. +As expected, the equilibrium constants are smaller by about four orders of magnitude ($\Delta G^\star_{cplx} \sim \SI{40}{\kilo\joule\per\mole}$) than those previously discussed. In water, the general order is $K_{22} \leq K_{02} < K_{12}$. However, for many compounds in the IIO and APO families, $K_{02}$ is larger than $K_{22}$, which is attributed to the interaction between the \ce{NMe4+} cation and the aromatic moiety present in these compounds. In acetonitrile, the \ce{N^-AC} complexes are again more stable than the others, consistently with previous observations \cite{wylieImprovedPerformanceAllOrganic2019a}. Thus, the dielectric constant significantly impacts the equilibrium constants of these ion-triplets. This is further confirmed by the observation that the stabilization of \ce{N^.AC} is less pronounced in this study than in Ref.~\citenum{wylieImprovedPerformanceAllOrganic2019a}, which employed a solvent with an even lower dielectric constant. \clearpage \subsection{Comparison to experiment} \label{sec:exp} -A comparison between theoretical (including all corrections discussed above) and experimental oxidation potentials is shown in Fig.~\ref{fig:expvstheo}. Excluding compounds bearing a \ce{NH2} group (so, \textbf{57} in water, and \textbf{4}, \textbf{51}, and \textbf{59} in acetonitrile) results in an excellent linear correlation ($R^2 \sim 0.9$). The fit indicates that the method used in this paper tends to slightly overestimate the oxidation potentials (by 0.05 to \SI{0.1}{\volt}) in water and systematically underestimate them in acetonitrile (by 0.3 to \SI{0.45}{\volt}), with a larger mean average error (MAE). This suggests that the value for $E^0_{abs}(\text{SHE})$ might not be appropriate in this solvent. +A comparison between theoretical (including all corrections discussed above) and experimental oxidation potentials is shown in Fig.~\ref{fig:expvstheo}. Excluding compounds bearing a \ce{-NH2} group (so, \textbf{57} in water, and \textbf{4}, \textbf{51}, and \textbf{59} in acetonitrile) results in an excellent linear correlation ($R^2 \sim 0.9$). The fit indicates that the method used in this paper tends to slightly overestimate the oxidation potentials (by 0.05 to \SI{0.1}{\volt}) in water and systematically underestimate them in acetonitrile (by 0.3 to \SI{0.45}{\volt}), with a larger mean average error (MAE). This suggests that the value for $E^0_{abs}(\text{SHE})$ might not be appropriate in this solvent. \begin{figure}[!h] \centering