2,4-dithiouracil: the reproducible H-bonded structural motifs in the complexes with 18-membered crown ethers.

Wen-Jwu Wang, Eduard V Ganin, Marina S Fonari, Yurii A Simonov, Gabriele Bocelli

Index: Org. Biomol. Chem. 3(16) , 3054-8, (2005)

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Abstract

2,4-dithiouracil (DTU) forms in the crystals the H-bonded monohydrates of a 1:1:1 ratio with 18-crown-6 (18C6) 1, cis,syn,cis-isomer of dicyclohexano-18-crown-6 (DCH6A) 2, and benzo-18-crown-6 (B18C6) 3, while the anhydrous adduct with cis,anti,cis-isomer of dicyclohexano-18-crown-6 (DCH6B) 4 is of a 2:1 ratio. In 1-3 the components reproducibly alternate in the chains, while in 4 the chains are built of the alternative centrosymmetric dimers of 2,4-dithiouracil and the molecules of the cis,anti,cis-isomer of dicyclohexano-18-crown-6.