The crystal and molecular structure of an osmium bispyridine adduct of thymine.

The bispyridine osmium adduct of thymine has been crystallised and subjected to an X-ray diffraction analysis. It crystallises in the triclinic space group P1, with cell dimensions a equals 7.975(3), b equals 10.381(3), c equals 11.036(3) A, alpha equals 82.73(2)degrees, beta equals 77.22(3) degrees, gamma equals 101.75(3), and with two molecules in the unit cell. The analysis has shown that the osmium reagent has added cis across the 5,6 thymine bond.