Effect of Weak Sulfur Interactions and Hydrogen Bonds in the Folded or Unfolded Conformation of bis[2-(1H-Benzimidazol-2-yl)phenyl]disulfide Derivatives

• Published in: Crystal growth & design Vol. 7; no. 10; pp. 2031 - 2040
• Main Authors: Esparza-Ruiz, Adriana, Peña-Hueso, Adrián, Hernández-Díaz, Julio, Flores-Parra, Angelina, Contreras, Rosalinda
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 01.10.2007
• Subjects: Condensed matter: structure, mechanical and thermal properties; Crystalline state (including molecular motions in solids); Crystallographic aspects of phase transformations; pressure effects; Exact sciences and technology; Organic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Phosphates; Weak interactions; Stacking sequence; Lewis acids; Fluoroborates; Perchlorates; Sulfates; Intermolecular interaction; Racemates; Hydrogen bonds; Supramolecular structure; Arrays; Sulfur; X-ray diffraction analysis; Intramolecular interaction; Conformation; Polymorphism; Crystal structure
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg070498h

Syntheses and structural study of the new compounds bis[2-(1H-benzimidazol-2-yl)phenyl]disulfide (1) and bis[2-(3H-benzimidazol-1-ium-2-yl)-phenyl]disulfide sulfate (2), and their corresponding bis-hydrogen sulfate (3), bis-dihydrogen-phosphate (4), bis-tetrafluoroborate (5) and bis-perchlorate (6), are reported. X-ray diffraction analyses of 2−6 and three pseudo-polymorphs of 1 have shown that the conformation of 1 is the result of sulfur weak N → S intramolecular interactions, where the sulfur atom is acting as a Lewis acid. Nitrogen protonation changes the elongated conformation of 1 into a folded conformation for 2−4 and a semifolded conformation in compounds 5 and 6 with the assistance of intramolecular π−π stacking and hydrogen bonds, which bridge the two halves of the molecules. All disulfides adopt chiral conformations in the solid state; the ensemble of these chiral conformations is racemic. They present polymeric arrays with multiple cooperative stabilizing intermolecular and intramolecular interactions like π-interactions, O → S, C(π) → S, N(π) → S, F → S, and H-bonds.