title: Assembly of the highest connectivity Wells-Dawson polyoxometalate coordination polymer: the use of organic ligand flexibility.
abstract: Through tuning the length of flexible bis(triazole) ligands and different metal ion coordination geometries, four Wells-Dawson polyoxoanion-based hybrid compounds, [Cu 6(btp) 3(P 2W 18O 62)].3H 2O ( 1) (btp = 1,3-bis(1,2,4-triazol-1-y1)propane), [Cu 6(btb) 3((P 2W 18O 62)].2H 2O ( 2), [Cu 3(btb) 6(P 2W 18O 62)].6H 2O (btb = 1,4-bis(1,2,4-triazol-1-y1)butane) ( 3), and [Cu 3(btx) 5.5((P 2W 18O 62)].4H 2O (btx = 1,6-bis(1,2,4-triazol-1-y1)hexane) ( 4), were synthesized and structurally characterized. In compound 1, the metal-organic motif exhibits a ladder-like chain, which is further fused by the ennead-dentate [P 2W 18O 62] (6-) anions to construct a 3D structure. In compound 2, the metal-organic motif exhibits an interesting Cu-btb grid layer, and the ennead-dentate polyoxoanions are sandwiched by two Cu-btb layers to construct a 3D structure. Compound 3 exhibits a (4 (2).6 (2).8 (2)) 3D Cu-btb framework with square and hexagonal channels arranged alternately. The hexa-dentate polyoxoanions incorporate only into the hexagonal channels. In compound 4, there exist two sets of (6 (1).10 (2)) 2(6 (1).8 (2).10 (3)) 3D Cu-btx frameworks to generate a 2-fold interpenetrated structure into which the penta-dentate polyoxoanions are inserted to construct a 3D structure. The structural analyses reveal that the length of flexible bis(triazole) ligands and metal ion coordination geometries have a synergic influence on the structures of this series. To our knowledge, they have the highest connectivity for the Wells-Dawson polyoxometalate coordination polymers to date.
authors.affiliation: Key Laboratory of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun, Jilin 130024, P.R. China.
authors.forename: Ai-xiang
authors.initials: AX
authors.lastname: Tian
authors.forename: Jun
authors.initials: J
authors.lastname: Ying
authors.forename: Jun
authors.initials: J
authors.lastname: Peng
authors.forename: Jing-quan
authors.initials: JQ
authors.lastname: Sha
authors.forename: Zhan-gang
authors.initials: ZG
authors.lastname: Han
authors.forename: Jian-fang
authors.initials: JF
authors.lastname: Ma
authors.forename: Zhong-min
authors.initials: ZM
authors.lastname: Su
authors.forename: Ning-hai
authors.initials: NH
authors.lastname: Hu
authors.forename: Heng-qing
authors.initials: HQ
authors.lastname: Jia