A Novel Right-Angled Ligand that Forms Polymeric Metal−Organic Frameworks with Nanometer-Sized Square Cavities

• Published in: Crystal growth & design 2005-03, Vol.5 (2), p.667-671
• Main Authors: Wong, Ken-Tsung, Liao, Yuan-Li, Peng, Ying-Chu, Wang, Chih-Chieh, Lin, Sue-Yi, Yang, Cheng-Han, Tseng, Shih-Min, Lee, Gene-Hsiang, Peng, Shie-Ming
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Organic compounds; Organometalloidal and organometallic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg049822o

A new right angle-shaped ligand, 2,2‘-bis(4-pyridyl)-9,9‘-spirobifluorene (L), is designed and synthesized. Treatment of L with silver(I) ions leads to linear polymeric metal−organic frameworks, [Ag(L)2]+ (1), that feature square subunits. Single-crystal X-ray analysis reveals that [Ag(L)2]+ has a one-dimensional double-stranded polymeric chain comprising square grids with cavity dimensions of ca. 8 Å × 8 Å. By π−π stacking of adjacent double-stranded chains, the structure is extended into a two-dimensional (2D) layer framework with a unique quasi-aperture (dimensions of ca. 14 Å × 8 Å). Each 2D layer is inclined and mutually interpenetrated, which gives rise to the three-dimensional interlocked network structure. Compound 1·(BF4)(CH3OH) crystallizes in the monoclinic system, space group C2/c, with chemical formula C71H49N4OBF4Ag, a = 25.709(1) Å, b = 14.4164(6) Å, c = 15.6865(7) Å, β = 109.220(2)°, and Z = 4.