The compound, 1-(ethoxymethyl)-6-(phenylselenyl)-5-ethyl uracil, crystalliz
es in the monoclinic space group P2(1)/n with unit cell parameters a = 5.30
4(1), b = 21.261(4), c = 13.996(4) Angstrom, beta = 94.30(2)degrees, and Z
= 4. The acyclic chain C1', O4', C4', C5' is in fully extended form and nea
rly perpendicular to the uracil base. The molecules are held together by va
n der Waal's forces.