Abstract
UV-spectrophotometric determination of dissociation constant (pK(a)) is used routinely in various research fields. This review highlights the structural attributes of organic compounds that exhibit distinct pH-sensitive UV-absorbance for ionized and unionized species qualifying for pK(a) measurement. Organic compounds must possess a double bond, the chromophore adjacent to the ionizing functional group. Compounds bearing up to five sigma bonds between the chromophore and ionizing group are eligible for UV-spectrophotometric determination of pK(a). This review serves as a quick guide for knowledge about structural requirements expediting pK(a) determination by UV-spectrophotometry. Besides, the study also identified the gap in research on pK(a) in drug discovery and food chemistry, revealing the necessity of determining pk(a) at the early stages of drug and food research to enhance the success rate in their development.