Empirical correlation for the energy of full charge-transfer exciplex relative to the ground state in
n-hexane as a function of the electrochemical one electron standard reduction potential of the cation radical produced upon electron donation and standard reduction potential of the acceptor measured in a polar solvent for the donor (D) and the acceptor (A) involved \[\Delta H(\text{D}^{+}\text{A}^{-},\text{hexane}) = e\left [ E^{0}(\text{D}^{+\bullet }/\text{D}) - E^{0}(\text{A}/\text{A}^{-\bullet }) \right ]+e\Delta E\] with E0(D+•/D) and E0(A/A-•) the standard electrode potentials of the donor and acceptor, respectively.
Notes: - In the case diethylaniline as donor and aromatic @H02889@ as acceptors, the last term on the right, i.e., eΔE = 0.15 ± 0.10 eV. This equation assumes a constant @C01365@ term and a constant @E02149@ change within a particular series of partners. e is the @E02032@.
- The IUPAC recommendations for the sign and symbols of standard potentials are used in the equation as written above.
- Although not complying with the IUPAC recommended nomenclature for the standard electrode potentials, traditionally the equation has been written as: \[\Delta H(\text{D}^{+}\text{A}^{-},\text{hexane}) = e\left [ E_{\text{ox}}^{0} - E_{\text{red}}^{0} \right ]+(0.15 \pm 0.10)\ \text{eV}\] with E(0)ox the @S05912@ at which the @O04362@ occurs, and E(0)red the @S05912@ at which the reduction occurs. This writing of the first term within the square brackets is misleading and not recommended.
Source:
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 439 (https://doi.org/10.1351/pac200779030293)