Synthesis and structure of an unprecedented meso-helixes dominated by bivanadyl-capped Keggin POMs

Abstract A new bivanadyl-capped Keggin polyoxometalates based hybrid containing the left- and right-handed helical chains, [Cu 12 (trz) 8 ][PMo 7 VI Mo 5 V O 40 (VO) 2 ]·H 2 O ( 1 ) (trz = 1,2,3-triazole), has been hydrothermally synthesized and structurally characterized by routine techniques. It is interesting that the left- and right-handed metal-organic helical chain are constructed from the rigid [Cu 5 (trz) 4 ] subunits with the same structure but different coordination directions, which is induced and stabilized by [PMo 12 O 40 (VO) 2 ] 4 − polyoxoanions. Note that the [PMo 12 O 40 (VO) 2 ] 4 − polyoxoanions link with fourteen Cu ions in the new compound, represents the highest linking number of Keggin POM clusters to date, and dominates to the formation of helical structures. In addition, the electrochemical properties of the new compound have been investigated.