title: A Pyridazine-Bridged Sandwiched Cluster Incorporating Planar Hexanuclear Cobalt Ring and Bivacant Phosphotungstate.
abstract: A planar hexanuclear cobalt ring was clamped by two bivacant α1-[PW10O37](9-) with the assistance of the pyridazine bridges to form a novel sandwiched Co(II)-polyoxometalate cluster compound, [Na(H2O)6][Co3(OH) (pydz)4(H2O)7][Co6(PW10O37)2(pydz)4(H2O)6]·43H2O (1; pydz = pyridazine).This cluster was identified by X-ray single-crystal diffraction, elemental analysis, Fourier transform IR and UV-visible spectroscopies, and cyclic voltammetry (CV). Structural analysis reveals that 1 comprises a hexahydrated sodium, a trinuclear [Co3(OH) (pydz)4(H2O)7](5+) cationic cluster, and an anionic [Co6(PW10O37)2(pydz)4(H2O)6](6-) sandwiched cluster, thus giving an intrinsical intercluster compound. The isolation of such cluster was dependent on the in situ transformation of trivacant [α-P2W15O56](12-) to α1-[PW10O37](9-) under the hydrothermal condition. The CV shows reversible multielectron waves from the redox of W(VI) in 1. Cluster 1 exhibits remarkable electrocatalytic activity toward the reduction of nitrite. Magnetism studies indicated a weak anti-ferromagnetic exchange interaction between Co(II) ions within 1.
authors.affiliation: Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, P. R. China.
authors.forename: Ling-Yu
authors.initials: LY
authors.lastname: Guo
authors.affiliation: School of Chemistry and Chemical Engineering, Liaocheng University , Liaocheng, P. R. China.
authors.forename: Su-Yuan
authors.initials: SY
authors.lastname: Zeng
authors.affiliation: Faculty of Civil and Geodetic Engineering & Institute of Mathematics, Physics and Mechanics, University of Ljubljana , Jamova 2, 1000 Ljubljana, Slovenia.
authors.forename: Zvonko
authors.initials: Z
authors.lastname: Jagličić
authors.affiliation: Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, P. R. China.
authors.forename: Qi-Dong
authors.initials: QD
authors.lastname: Hu
authors.affiliation: Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, P. R. China.
authors.forename: Shi-Xuan
authors.initials: SX
authors.lastname: Wang
authors.affiliation: Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, P. R. China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan 250100, P. R. China.
authors.forename: Di
authors.initials: D
authors.lastname: Sun