A feasible route to approach 3D POM-based hybrids: utilizing substituted or reduced Keggin anions with high charge density

• Published in: Dalton transactions : an international journal of inorganic chemistry 2012-08, Vol.41 (31), p.9365-9372
• Main Authors: Zhang, Chun-Jing, Pang, Hai-Jun, Tang, Qun, Chen, Ya-Guang
• Format: Article
• Language: English
• Subjects: Anions; Anions - chemistry; Atomic properties; Catalysis; Chains; Charge density; Clusters; Coloring Agents - chemistry; Coloring Agents - radiation effects; Luminescence; Metals, Heavy - chemistry; Photocatalysis; Photoelectron Spectroscopy; Photolysis; Powder Diffraction; Rhodamines - chemistry; Rhodamines - radiation effects; Silver; Spectrophotometry, Infrared; Thermogravimetry; Three dimensional; Tungsten Compounds - chemistry; X-Ray Diffraction
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c2dt30152k

Five new hybrid compounds based on Keggin polyanions, Ag(+)/Cu(+) ions and 1,3-bis(1,2,4-triazol-1-yl)propane (btp) molecules have been hydrothermally synthesized. In [Ag(5)(btp)(4)(H(2)O)(2)][PCuW(11)O(39)]·2H(2)O (1), [Ag(4.33)Na(0.67)(btp)(4)(H(2)O)(2)][PMnMo(11)O(39)]·H(2)O (2) and [Cu(4)(btp)(4)Na(H(2)O)(2)][PMnMo(11)O(39)]·2H(2)O (3), the neighboring mono-substituted Keggin clusters are alternately connected via sharing oxygen atoms to form an unusual Keggin-based transition-metal monosubstituted chain, in which the Keggin cluster serves as a decadentate ligand and grafts ten metal atoms representing the highest connected number for Keggin cluster and forming a 3D framework. In [Ag(5)(btp)(4)][PW(VI)(10)W(V)(2)O(40)] (4) and [Ag(5)(btp)(4)][PMo(VI)(10)Mo(V)(2)O(40)] (5), two-electron reduced Keggin clusters as hexadentate linkages are inserted in the rhomboid-like tunnels of the Ag-btp framework and connect with the framework via six Ag-O bonds to achieve 3D motifs, which are new and rare examples of heteropoly blue based hybrid compounds. The successful synthesis of the five high-dimensional structures may provide a feasible route for us to approach 3D polyoxometalate-based hybrids by using substituted Keggin anions and heteropoly blues with high charge density. Furthermore, photocatalytic experiments indicate that both 1 and 4 have good activities for photocatalytic degradation of RhB under UV irradiation. The luminescent properties of compounds 1-5 in the solid state were also investigated.