Physicochemical studies on starches. VII. The infrared absorption spectrum of the amylose‐iodine complex

Changes in the infrared absorption spectrum of amylose on complex formation with iodine, bromine, and iodine cyanide vapor are consistent with the occurrence of halogen‐oxygen interaction in the solid complexes. The implications of these results are discussed in terms of the possible conformations of the glucopyranose rings and their relationships to the helical structure for amylose. It is suggested that the most probable conformation is a chair‐form in which only one substituent is axial to the plane of the ring.