INFRARED STUDY OF ALKYL CARBOXYLIC-ACIDS IN CCL4 AND OR CHCL3 SOLUTIONS/

Infrared data for acetic acid, propionic acid, butyric acid, isobutyri c acid and trimethylacetic acid in 0.2 g 100 ml(-1) CHCl3 and/or CCl4 solutions are included in this study. The upsilon(C=O) and upsilon(op) (C=O)(2) modes are apparently affected by both inductive and steric ef fects. Intermolecularly hydrogen-bonded complexes are suggested to be formed between the carbonyl oxygen atom of the carboxylic acids and th e chloroform proton and the CO2H proton of the carboxylic acids and th e Cl atom of chloroform, and these complexes change as the mole% CHCl3 /CCl4 increases. The concentration of the solution complexes formed wi th the intermolecularly hydrogen-bonded carboxylic acid dimer decrease s, while the concentration of the solution complexes formed between th e RCO(2)H monomer increases as the mole% CHCl3/CCl4 increases.