The Effect of Steric Hindrance on the Association of Telluradiazoles through Te−N Secondary Bonding Interactions

• Published in: Crystal growth & design 2006-01, Vol.6 (1), p.181-186
• Main Authors: Cozzolino, Anthony F, Britten, James F, Vargas-Baca, Ignacio
• Format: Article
• Language: English
• Subjects: Aliphatic, non-condensed and condensed benzenic, and alicyclic compounds; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Organic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg050260y

DFT calculations were used to compare the magnitude of steric repulsion to the strength of secondary bonding interactions (SBIs) in the (Te−N)2 supramolecular synthon to explain or predict the supramolecular structures assembled by two derivatives of the 1,2,5-telluradiazole ring:  benzo-2,1,3-telluradiazole (4c) and 3,6-dibromobenzo-2,1,3-telluradiazole (5). The crystallographically determined structures were consistent with the computational predictions. In sharp contrast with the previously known structures of its sulfur and selenium analogues, 4c forms infinite ribbon chains in the solid state with 2.682(7)−2.720(7) Å Te−N SBIs. Steric hindrance in 5 restricted the supramolecular association to form discrete dimers with 2.697(8) Å Te−N SBIs. In addition to discrete dimers, the dibromo derivative crystallizes as solvated dimers in 5·DMSO with 2.834(5) Å Te−O SBIs. Other weaker SBIs were identified in the crystal lattices and were assessed by the computational method.