Crystal structures of three N,N,N'-tris-ubstituted thio-ureas for reactivity-controlled nanocrystal synthesis

The synthesis and single-crystal X-ray structures of three N,N,N'-tris-ubstituted thio-ureas are reported, namely N,N,N'-tri-benzyl-thio-urea, C₂₂H₂₂N₂S (1), N-methyl-N,N'-di-phenyl-thio-urea, C₁₄H₁₄N₂S (2), and N,N-di-n-butyl-N'-phenylthio-urea, C₁₅H₂₄N₂S (3). The influence of the different substituents on the thio-ureas is clear from the delocalization of the thio-urea C-N and C=S bonds, while the crystal structures show infinite chains of N,N,N'-tri-benzyl-thio-urea (1), hydrogen-bonded pairs of N-methyl-N,N'-di-phenyl-thio-urea (2) and hexa-mer ring assemblies of N,N-di-n-butyl-N'-phenylthio-urea (3) mol-ecules. The above-mentioned compounds were synthesized via a mild, general procedure, readily accessible precursors and with a high yield, providing straightforward access to a whole library of thio-ureas.