Investigation of the Inclusion of the Herbicide Metobromuron in Native Cyclodextrins by Powder X-ray Diffraction and Isothermal Titration.

VINCENT J. SMITH; NATALIA M. ROUGIER; RITA H. DE ROSSI; MINO R. CAIRA; ELBA I. BUJÁN; MARIANA A. FERNÁNDEZ; SUSAN A. BOURNE

CARBOHYDRATE RESEARCH

Elsevier

Año: 2009 vol. 344 p. 2388 - 2393

0008-6215

We report the formation of inclusion complexes between the phenylurea herbicide metobromuron [3-(pbromophenyl)-1-methoxy-1-methylurea] and beta- and ganma-cyclodextrin in the solid state. Formation of crystalline inclusion complexes by the kneading method was confirmed by powder X-ray diffraction and further structural characterization using the principles of isostructurality followed. In addition, DH, DS, DG and the association constants (K) at 298 K were determined for complex formation in solution using isothermal titration calorimetry. The magnitudes of K for the formation of 1:1 complexes between metobromuron and alfa-, beta- and ganma-CD were estimated as 598, 310 and 114, respectively.