Structural studies of supramolecular β-cyclodextrin complexes with butyrophenone and valerophenone: An explanation for photochemical reaction modification

X-Ray crystallographic studies of β-cyclodextrin (β-CD) inclusion complexes with butyrophenone and valerophenone characterize these complexes as 2:2 β-CD/guest systems with the alkyl chains of the included guest molecules conformationally restricted; the structures explain the reported observation of the modification of the Norrish type II photoreaction for the included aryl alkyl ketones in crystalline β-CD complexes.