Elusive pKa’ of aminoferrocene determined with voltammetric methods in buffered and unbuffered systems and practical aspects of such experiments

Persistent Radical Pairs between N‐Substituted Naphthalimide and Carbanion Exhibit pKa‐Dependent UV/Vis Absorption

“…Knowing the p K a value of a deprotonatable carbon atom attached to a functional group (CH x R y , defined as a carbon acid, CA, where x >0, y >0, and R representing the functional group) is critical in organic chemistry since it foretells the reactivity and selectivity of reactions participated by the α‐carbon. Over the past century, a plethora of experimental techniques, including potentiometry, spectrometry, conductometry, electrophoresis, nuclear magnetic resonance (NMR), voltammetry, high‐performance liquid chromatography (HPLC), fluorometry, and more recently, theoretical calculations, have been employed to measure or estimate the p K a values of organic compounds. Among these techniques, the UV/Vis spectroscopy method, similar to pH indicators, is particularly favored due to its wide accessibility, high throughput, and easy operation for non‐experts.…”

Electrochemical Properties of Carbon Paste Electrodes Modified with Fluorinated Materials

“…Figure 3 shows the voltammograms of (A) ferrocenecarboxylate (FcCOO ¹ ), were negatively and positively charged, respectively, since the pK a of FcCOOH is 4.2, 23 and that of FcNH 3 + is 5.9. 24 A qausi-reversible wave with a pair of anodic and cathodic current peaks of FcCOO ¹ was obtained in 0.1 M buffer (broken curve in Fig. 3A), whereas a very broadened voltammetric signal with no anodic peak was observed in 1 mM buffer (solid curve in Fig.…”

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

“…Knowing the pK a value of a deprotonatable carbon atom attached to a functional group (CH X R Y , X>0, a carbon acid, CA) is critical in organic chemistry since it foretells the reactivity and selectivity of reactions participated by the -carbon. Over the past century, a plethora of experimental techniques, including potentiometry, 1,2 spectrometry, [3][4][5] conductometry, 6,7 electrophoresis, 8,9 nuclear magnetic resonance (NMR), 10,11 voltammetry, 12,13 high performance liquid chromatography (HPLC), 14,15 fluorometry, [16][17][18] and more recently, theoretical calculations, 19,20 have been employed to measure or estimate pK a . Among these techniques, the UV-vis spectrometry method, similarly to pH indicators, is particularly favoured due to its wide accessibility, high throughput, and easy operation for nonexperts.…”