Structural diversity in coordination polymers with a semirigid Lewis acidity ligand: structures and properties

• Published in: CrystEngComm 2015-01, Vol.17 (30), p.5690-5701
• Main Authors: Huang, Yong-Qing, Cheng, Hai-Di, Chen, Huai-Ying, Wan, Yi, Liu, Cheng-Long, Zhao, Yue, Xiao, Xin-Feng, Chen, Li-Hui
• Format: Article
• Language: English
• Subjects: Channels; Coordination polymers; Diamonds; Displays; Ligands; Networks; Three dimensional; Two dimensional
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/C5CE00677E

Reaction of semirigid Lewis acidity ligand 1-carboxymethylpyridinium-4-carboxylate (L) with various salts affords five new coordination networks: two 2D layered coordination polymers [Ag sub(2)(L)(NO sub(3))]. H sub(2)O (2) and [Pb(L)(NO sub(3))] (3), and three 3D metal-organic frameworks [Cu sub(4)(L) sub(4)(OH) sub(2)Cl sub(2)].11.55H sub(2 )O (1), [Pb sub(3)(L) sub(4)Br sub( 2)(H sub(2)O) sub(2)] (4) and [Pr(L) sub(2)(H sub(2)O) sub(2)(NO sub(3))] (5). Complex 1 features a planar tetranuclear [Cu sub(4)( mu sub(3)-OH) sub(2)] super(6-) cluster as a 6-connected node, connecting with eight L ligands to generate a tilted alpha -Po type structure. Compared with 1, 2 possesses a unique 2D double-layered structure with 1D channels, which is composed of (4,4) topological networks pillared by nitrate anions. Complexes 3 and 4 are both made up of 1D chains. 3 is composed of homo-chiral 2 sub(1) helices, which provides a chiral 2D polymeric network, whereas 4 consists of two types of infinite 1D chains linked in a cross-like fashion, which displays a 3D plywood-like structure. Complex 5 consists of 4-connected metal nodes, which exhibits a 3-fold interpenetrating 3D diamondoid framework. The results suggest that the semirigid L ligand adopting different coordination modes plays important roles in determining the final structures of complexes 1-5. Moreover, complexes 3 and 5 with an acentric space group show modest powder second-harmonic-generation (SHG) efficiency at room temperature. Based on the Lewis acidity of the pyridinium unit of ligand L, complexes 1-5 were also used as catalysts for aza-Diels-Alder reaction.