Chalcogen atom effects on the rates of hydrolysis of chalcogenopyrylium dyes

Research was conducted to examine chalcogen atom effects on the rates of hydrolysis of chalcogenopyrylium dyes. Results indicate that the qualitative ordering of the rates can be rationalized in terms of higher stability of the thiopyrylium ring relative to the selenopyrylium ring. Findings also show that the decreasing electronegativity of the chalcogen atoms as size increases would tend to stabilize the cationic charge inductively, predicting the opposite trend in stability.