The Assembly of Phosphometalate Clusters with Copper Complex Subunits

Six organic–inorganic hybrid compounds based on a phosphometalate cluster with copper complex subunits: {[Cu(phen) 2 ] 2 Cl}(PMo 12 O 40 ) · H 2 O ( 1 ), {[Cu(phen) 2 ] 2 Cl}(PW 12 O 40 ) · H 2 O ( 2 ), [CuI(bpy) 2 ] 2 {[CuII(bpy)] 2 P(Mo V ) 3 (Mo VI ) 9 O 40 } ( 3 ), H[Cu(bpy)(H 2 O)]{[Cu(bpy)] 4 (PO 4 ) 2 }(PW 11 CuO 39 ) · H 2 O ( 4 ), [Cu(phen)(H 2 O)] 3 [(PO 4 ) 2 Mo 5 O 15 ] · 5H 2 O ( 5 ), and HNa[Cu(bpy)(H 2 O)] 2 [(PO 4 ) 2 Mo 5 O 15 ] · 6H 2 O ( 6 ) (phen = 1,10‐phenanthroline, bpy = 2,2′‐bipyridine) have been solvothermally synthesized. Single‐crystal X‐ray diffraction reveals that compounds 1 and 2 are composed of a Keggin polyoxoanion (PM 12 O 40 ) 3– (M = Mo, W) and {[Cu(phen) 2 ] 2 Cl} 3+ counterion. Compound 3 is built from two [Cu I (bpy) 2 ] + cations and a reduced‐Keggin polyoxoanion [PMo V 3 Mo VI 9 O 40 ] 6– which is bi‐capped by two [Cu II (bpy)] 2+ through four bridging oxo groups on two opposite (Mo 4 O 4 ) faces. Compound 4 is based on a monovacant Keggin anion (PW 11 CuO 39 ) 5– linked through four Cu(bpy) 2+ , two PO 4 3– , and one {H[Cu(bpy)(H 2 O)]} 3+ , generating a one‐dimensional chain. Compounds 5 and 6 exhibit a chain‐like structure constructed from [(PO 4 ) 2 Mo 5 O 15 ] 6– clusters linked through [Cu(phen)(H 2 O)] 2+ and [Cu(bpy)(H 2 O)] 2+ components, respectively. The pH is crucial for the isolation of the compounds. Compounds 1 and 2 are obtained in the pH range 1–2 with the phen ligand, and 3 and 4 are isolated in the pH range 3–4 and 2–3 with the bpy ligand, respectively. Oxalic acid acting as a reductant reduces the molybdenum ion from Mo VI to Mo V in 3 . Compounds 5 and 6 are produced in the pH range 3–4 with phen and bpy ligands, respectively. Compound 3 shows fluorescence due to the charge transfer from Cu I ‐to‐ligand (MLCT) [d 10 ‐π*]. Compound 4 displays magnetic behavior based on the super‐interaction through the tri‐copper six‐membered ring [Cu II –O–Cu II –O–Cu II –O–]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)