N-hetercycle dimeric molybdenum(V) complexes with strong interactions and their catalytic degradations of methyl orange

Abstract A series of dimeric N -hetercycle oxomolybdenum(V) complexes cis -Mo 2 O 4 (SO 4 )(phen) 2 ·2H 2 O ( 1 ), cis -Mo 2 O 4 (SO 4 )(bpy) 2 ·4H 2 O ( 2 ), cis -Mo 2 O 4 Cl 2 (bpy) 2 ( 3 ) and cis -Mo 2 O 4 (SO 4 )(im) 4 ( 4 ) (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine, im = imidazole) have been synthesized and characterized by the elemental analyses, IR, UV–vis, molecular fluorescence spectra, X-ray structural analyses and theoretical calculations. The two N -hetercycle ligands in 1 or 2 exhibit an approximate plane owing to SO 4 2− steric hindrance with strong interactions (2.215 av and 2.186 av  A), which are new discrete dinuclear oxomolybdenum(V) complexes. 1 – 3 have been synthesized in acidic media under hydrothermal conditions and the transformations of oxomolybdenum(V) 2 – 3 and 1 to cis -Mo 2 O 4 Cl 2 (phen) 2 ( 5 ) are also outlined respectively. Moreover, the catalytic performances of 1 – 5 were tested by the degradation of methyl orange. The conjugated N -hetercycle ligands have obvious influences on their catalytic performances.