Directed Synthesis of a 1D Double‐Chain Polyoxometalate Assembly: {[Ag 2 (bppy) 3 ][Ag(bppy) 2 ][Ag(bppy)] 2 PW 11 Co(bppy)O 39 }·2H 2 O

A 1D double‐chain assembly based on the monosubstituted Keggin polyoxometalate (POM) with pendant ligands and of formula {[Ag 2 (bppy) 3 ][Ag(bppy) 2 ][Ag(bppy)] 2 PW 11 Co(bppy)O 39 }·2H 2 O ( 1 ) [bppy = 5‐(4‐bromophenyl)‐2‐(4‐pyridinyl)pyridine] has been synthesised and characterised. The crystals of 1 belong to the space group P $\bar 1$ , Mr = 5801.06, a = 18.720(4) Å, b = 19.474(4) Å, c = 19.815(4) Å, α = 96.30(3), β = 96.07(3), γ = 90.12(3)°, V = 7139(2) Å 3 , Z = 2, D calcd. = 2.699 Mg·m −3 . The final statistics based on F 2 are GOF = 1.007, R 1 = 0.0620 and wR 2 = 0.1346 for I > 2σ( I ). X‐ray diffraction analysis revealed that the structure of 1 contains a 1D chain constructed from a monosubstituted tungstophosphate with one pendant conjugated ligand, five silver−bppy groups and two water molecules. The periphery of the Keggin cluster consists of five Ag−bppy groups so that a bicapped trisupporting Keggin structure is obtained. It is rare that a Keggin anion cluster is simultaneously coordinated to five transition metal atoms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)