Persistent Radical Pairs Between N-Substituted Naphthalimide and Carbanion Exhibit pKa-Dependent UV-vis Absorption

Abstract

A new strategy is constructed for estimating and screening pK<sub>a</sub> values among different carbon acids under ambient conditions via the UV-vis absorption spectrum of persistent radical pair originating from an <i>N</i>-substituted naphthalimide (NNI) derivative in the presence of various carbanions in organic solutions

2D-Map of Intermolecular Interactions in Organic Chemistry Reveals Underrepresented Area of Research

“…When two organic molecules are in proximity with one another, many types of bimolecular interactions (BMI) could happen, including 1) chemical reactions with new bond formation and old bond cleavage, 2) spontaneous single-electron transfer resulting a pair of radicals, 1,2 and 3) non-bonding interactions such as hydrogen and halogen bonds, 3,4 π-π stacking 5,6 or simply Van der Waals forces. However, definitions for such interactions are largely loose or intuitive with many overlapping characteristics.…”

“…It is well-known that a radical pair (RP) is created post singleelectron transfer. 1,2,15 However, it must also be considered that cases in B2 should also exhibit bonding character, i.e., localized electron pair. If we designate the RP state as Ψ RP and chemical bonding state as Ψ CB , the "hybrid" B2 state should be described as Ψ Hybrid = (a<Ψ RP | + b<Ψ CB |)/N, where a and b are weight factors, and N is the normalization factor.…”