Steric Control over Hydrogen Bonding in Crystalline Organic Solids: A Structural Study of N,N′-Dialkylthioureas

✍ Scribed by Radu Custelcean; Maryna G. Gorbunova; Peter V. Bonnesen

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 414 KB
• Volume: 11
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200400973

✦ Synopsis

Abstract

Hydrogen bonding in crystalline N,N′‐dialkylthioureas was examined with the help of single‐crystal X‐ray diffraction, DFT calculations, and Cambridge Structural Database (CSD) analysis. A CSD survey indicated that unlike the related urea derivatives, which persistently self‐assemble into one‐dimensional hydrogen‐bonded chains, the analogous thioureas can form two different hydrogen‐bonding motifs in the solid state: chains, structurally similar with those found in ureas, and dimers, that further associate into hydrogen‐bonded layers. The formation of one motif or another can be manipulated by the bulkiness of the organic substituents on the thiourea group, which provides a clear example of steric control over the hydrogen bonding arrangement in crystalline organic solids.