The crystal and molecular structure of 2-S-methylthiouracil

2-S-Methylthiouracil crystallizes in the triclinic space group P (1) over b ar with unit cell dimensions a = 5.508(4), b = 7.175(3), c = 8.522(2) Angst rom, alpha = 80.83(2), beta = 80.43(3), gamma = 76.86(3)degrees, and Z = 2. The molecule exists in the crystal in the lactam form and is essentially p lanar. The molecular packing consists of molecules linked in centrosymmetri c hydrogen-bonded pairs. The effects of methylation and subsequent metallat ion on the 2-thiouracil structure are discussed.