Abstract: The interaction between chitosan (CS) and 1-hydroxybenzotriazole (HOBt) was characterized by ¹H NMR spectroscopy, NMR diffusion measurement, and solid-state high-resolution ¹³C NMR spectroscopy. It was found that CS and HOBt can form organic complex in aqueous solution, with hydrogenbond interaction as the main binding force. The association constant of CS/HOBt complex was calculated from the self-diffusion coefficient of HOBt. The interaction between CS and HOBt can potentially be utilized for efficient chemical modification of CS.

Key words: NMR, chitosan, 1-hydroxybenzotriazole, hydrogen-bond interaction, self diffusion coefficient