Metal diphosphonates with double-layer and pillared layered structures based on N-cyclohexylaminomethanediphosphonate

✍ Scribed by Yan-Hui Su; Deng-Ke Cao; Yan Duan; Yi-Zhi Li; Li-Min Zheng

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 814 KB
• Volume: 183
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2010.05.008

✦ Synopsis

Based on N-cyclohexylaminomethanediphosphonic acid (cmdpH 4 ), four new metal diphosphonate compounds with formula M 3 (cmdpH) 2 (H 2 O) 2 [M¼ Zn(1), Co(2)] and M 2 (cmdpH 2 ) 2 (4,4 0 -bipy) 0.5 (H 2 O) [M¼ Co(3), Mn(4)] have been obtained and structurally determined. Compounds 1 and 2 are isostructural. Within the structure, the M(2)O 6 octahedra are each corner-shared with four PO 3 C tetrahedra to form a single layer containing 3-and 7-member rings. Neighboring single layers are pillared by M(1)O 4 tetrahedra, resulting in a novel double-layer structure. The organic moieties of cmdpH 3 À are grafted on the two sides of the double layer. Compounds 3 and 4 are also isostructural, displaying a pillared layered structure. Within the inorganic layer, the M(1)O 5 tetragonal pyramids and M(2)NO 5 octahedra are each linked by PO 3 C tetrahedra through corner-sharing, forming a layer in the ab plane which contains 3-and 10-member rings. These layers are pillared by 4,4 0 -bipyridine via coordination with the M(2) atoms from the adjacent layers, leading to a three-dimensional open framework structure with channels generated along the a-axis. The organic groups of cmdpH 2 2 À locate within the channels. Magnetic studies show that antiferromagnetic interactions are dominant in compounds 2-4. Field dependent magnetization reveals a spin flop behavior for 2.