Table 2.

Electrochemical data for dimeric and monomeric 2-Y-DMBI compounds,^[a] and adiabatic ionization energies (IEs) and dissociation energies obtained from M06/LANL2DZ/6-31G(d,p) calculations for various 2-Y-DMBI species.

	E vs. FeCp2 +/0 / V [a]		IE / eV[d]			ΔUdiss / kJ mol−1 (eV)[d]
Y	Epa(D2 +/0)[b]	Epc(D+/0)[c]	D2→D2•++e[e]	D•→D++e	0.5D2→D++e[f]	D2→2D•	D2•+ →D+ + D •[e]
Cyc	−0.64	−2.45	5.06	3.72	4.81	210 (2.17)	81 (0.84)
Fc	−0.89	−2.24	4.69	3.93	4.79	165 (1.71)	91 (0.94)
Rc	−0.59	−2.29	4.68	3.80	4.73	181 (1.87)	97 (1.00)

^[a]In THF / 0.1 M ⁿBu₄NPF₆.

^[b]Peak potential for the irreversible oxidation of D₂ measured at 100 mV s⁻¹.

^[c]Peak potential for the partially reversible reduction of D⁺ at 100 mV s⁻¹.

^[d]Gas-phase adiabatic IEs and dissociation energies obtained from DFT calculations.

^[e]These results should be treated with caution owing to the tendency of DFT to artificially over-delocalize odd-electron systems such as these cations due to self-interaction error^[22] Indeed the optimized structures for the D₂ ^•+species are all characterized by spuriously long central C—C bonds (3.23-3.34 Å).

^[f]IE_eff(0.5D₂→D⁺+e) = IE(D) + 0.5ΔU_diss(D₂).