A new compound based on Preyssler-type P5W30 anion modified by CoII and flexible bis(benzimidazole) ligand

A new Preyssler-type polyoxometalates-based inorganic–organic hybrid compound [Co(Hbbbm)2(H2O)2(H2P5W30O110)]2·9H2bbbm·20H2O (1) [bbbm = 1,1′-(1,4-butanediyl)bis-1 H-benzimidazole] has been synthesized under hydrothermal conditions and characterized by IR, TG and XRD. Single crystal X-ray diffraction analysis reveals that compound is composed of two Preyssler-type [H2P5W30O110]13− anions (P5W30), two [Co(Hbbbm)2(H2O)2]4+ cations, nine discrete protonated [H2bbbm]2+ molecules and twenty crystallization water molecules. Two P5W30 anions are covalently bridged by two [Co(Hbbbm)2(H2O)2]4+ cationic fragments to form a P5W30-based dimer. The dimers are ultimately extended to a three dimensional (3D) network by π∙∙∙π stacking and hydrogen-bonding interactions. Compound represents the first bisupporting Preyssler-type structure modified by transition metal coordination complex (TMC). Additionally, the electrochemical behavior and electrocatalysis of compound have been investigated.