Hydrothermal syntheses and structural characterizations of three polyoxomolybdates frameworks linked by M(HL) 2 units (M = Co, Ni, Zn; L = 3-(2-pyridyl)pyrazole)

Three polyoxomolybdate compounds, namely {[M II (HL) 2 ] 2 (Mo 8 O 26 )} n (M = Co ( 1 ), Ni ( 2 ), Zn ( 3 )) (HL, 3-(2-pyridyl)pyrazole), were designed and synthesized under the hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and TGA. Single-crystal X-ray diffraction analysis results reveal that compounds 1 – 3 own the isostructural chain structure consisting of the β-[Mo 8 O 26 ] 4− anions, which are linked by M(HL) 2 2+ units via the terminal oxygen atoms. TGA curves show that the organic ligands separate from the related compounds above ca. 673 K.