Two Polyoxometalate‐Based Hybrid Compounds Modified by Iron Schiff Base Complexes: Syntheses, Crystal structures, Cyclic Voltametric Studies and Nonlinear Optical Properties

Abstract

Abstract Two new polyoxometalate (POM)‐based hybrid compounds modified by a Schiff base, [Fe(DAPSC)(H 2 O) 2 ] 2 [HPMo 2 V Mo 10 VI O 40 ] ⋅ 5H 2 O ( 1 ) and [Fe(DAPSC)(H 2 O)] 2 [HPV 3 IV Mo 4 V Mo 7 VI O 42 ] ⋅ 6H 2 O ( 2 ), (DAPSC=2,6‐diacetylpyridine bis‐(semicarbazone)), have been successfully constructed from typical Keggin POMs, iron ions, and DAPSC ligands under hydrothermal condition. Structural analysis demonstrates that the Fe‐Schiff base ligand units are free from polyacid anions in compound 1 . While in compound 2 , the Fe‐Schiff base ligand units are bridged with polyacid anions via Fe−O bonds to emerge a stable double‐supported skeleton. Noticeably, owing to the introduction of vanadium in H 5 PMo 10 V 2 O 40 ⋅ 32.5H 2 O, a divanadium‐capped configuration is shaped in compound 2 . Besides, the third‐order nonlinear optical (NLO) properties of two compounds were explored. It should be noted that both compounds 1 and 2 have two‐photon absorption properties, which indicates that the two compounds are potential nonlinear optical materials.