Crystal structure of the charge transfer complex 9-cyclohexyladenine-iodine

The crystal structure of the charge-transfer complex of iodine with 9-cyclohexyladenine, C₁₁H₁₅I₂N₅, has been determined, and refined by three-dimensional least-squares techniques. The crystals are monoclinic:P2₁/c,Z = 4,a = 9·1728(7),b = 12·289(1),c = 13·596(1) Å, = 99·564 °(6). The finalR value for 3629 reflexions is 0·039. The iodine forms a charge-transfer bond with N(1) of the adeninering, with an N—I bond length of 2·520(3) Å. The I—I—N(1) arrangement is approximately linear (bond angle, 177·1 °). The I—I molecule makes an angle of 21·5 ° with the plane of the adenine ring.Supported by N. I. H. Development Award 5-K4-GM-42572.