Hydrothermal syntheses, crystal structures and topological analyses of four new 3D coordination polymers with mixed ligands

• Published in: Inorganica Chimica Acta 2011-10, Vol.376 (1), p.332-339
• Main Authors: Bai, Hong-Ye, Ma, Jian-Fang, Liu, Ying-Ying, Yang, Jin
• Format: Article
• Language: English
• Subjects: Carboxylate; Coordination polymers; Mixed ligands; Terakis(imidazole)
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2011.06.043

Four metal–organic frameworks based on tetrakis(imidazol-1-ylmethyl)methane have been successfully synthesized by varying the metal centers and the carboxylate ligands, where thermal and photoluminescent properties were also investigated. [Display omitted] ► Two kinds of in situ reaction were observed under hydrothermal condition. ► The structures are greatly affected by the carboxylate anions. ► The emissions of 2 and 4 can be attributed to intraligand transitions. Four new coordination polymers, namely [Ni1.5(L)(fum)0.5(mal)(H2O)]·4H2O (1), [Zn2(L)(male)2]·3H2O (2), [Ni(L)(adi)0.5(H2O)]·0.5(adi)·2.5H2O (3), and [Zn2(L)(adi)2]·5H2O (4) (L, tetrakis(imidazol-1-ylmethyl)methane; fum, fumarate; mal, malate; male, maleate; adi, adipate) have been synthesized under hydrothermal condition and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. In compound 1, the L, fum, and mal connect the Ni(II) atoms to form a three-dimensional framework. Topologically, the compound shows a trinodal (3,4)-connected (4·102)(42·82·102)(42·84) net. Interestingly, the fum and mal came from the configuration transformation and addition reaction of maleate during the synthesis, respectively. In compound 2, the L ligands link the Zn(II) centers to generate a 2D layer, which are further connected by the male ligands to furnish a 3D chrial 4-connected (3·75) net. In compound 3, the adi ligands and the L ligands link the Ni(II) centers to form a 3D framework. Topologically, compound 3 displays a (4,5)-connected net with the Schläfli symbol of (42·52·62)(42·53·64·7). In compound 4, the L and adi ligands link the binuclear Zn(II) clusters to yield an intricate 3D (3,6)-connected net with the Schläfli symbol of (4·62)(43·612). The fluorescence and thermal stability of complexes 1–4 have also been investigated.