title: Improved competitive indicator methods for the study of alpha-cyclodextrin complexes.
abstract: The competitive indicator method for studying molecular complexes is extended to systems forming 1:1 (SL) and 1:2 (SL2) complexes of substrate (S) and ligand (L). A modification is described for slightly soluble substrates, in which the presence of solid substrate establishes a constant concentration of uncomplexed substrate. These methods are applied to complexes of alpha-cyclodextrin with some aromatic substrates, with methyl orange as the indicator in acid solution; nitrazine yellow is introduced as an indicator for these studies in basic solution.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003505:Cyclodextrins / Q000032:analysis*; D003912:Dextrins / Q000032:analysis*; D004355:Drug Stability; D007202:Indicators and Reagents; D011199:Potentiometry; D012995:Solubility; D013053:Spectrophotometry; D013213:Starch / Q000032:analysis*; D047391:alpha-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D003912:Dextrins; D007202:Indicators and Reagents; D047391:alpha-Cyclodextrins; D013213:Starch; C032613:alpha-cyclodextrin