Polyoxometalate-based complexes with a flexible bis-imidazole-bis-amide ligand: structures, electrochemical and photocatalytic properties

• Published in: Transition metal chemistry (Weinheim) 2019-04, Vol.44 (3), p.207-217
• Main Authors: Wang, Xiuli, Pan, Xiang, Wang, Xiang, Liu, Guocheng, Lin, Hongyan, Zhang, Shan
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Organometallic Chemistry; Physical Chemistry
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1007/s11243-018-0284-7

Three different polyoxometalate (POM)-based complexes, [Co L (H 2 O)( α -Mo 8 O 26 ) 0.5 ]·4H 2 O ( 1 ), [Ni L (H 2 O)( θ -Mo 8 O 26 ) 0.5 ]·4H 2 O ( 2 ) and [Ag 2 L 2 ][HPMo 12 O 40 ]·3H 2 O ( 3 ) ( L =  1, 2 bis(1H-imidazole-4-carboxamido)ethyl) have been synthesized under hydrothermal conditions. The different heterometals lead to two types of polyoxomolybdates, specifically [ α -Mo 8 O 26 ] 4− and [ θ -Mo 8 O 26 ] 4− in complexes 1 and 2 , respectively. In complex 1 , the [ α -Mo 8 O 26 ] 4− anions are linked into a 1D chain by [Co 2 L 2 (H 2 O) 2 ] 4+ cations. Replacing Co 2+ with Ni 2+ , [ θ -Mo 8 O 26 ] 4− anions were constructed in complex 2 . In contrast, a discrete metal–organic cation [Ag 2 L 2 ] 2+ and Keggin-type [PMo 12 O 40 ] 3− anion resulted when Ag + was used to prepare complex 3 in the presence of phosphoric acid. The electrochemical and photocatalytic properties of all three complexes were studied.