From polyoxometalate building blocks to polymers and materials: the silver connection

Molecular growth processes utilizing polyoxometalate-based building blocks with silver connecting units have been used to produce four new materials: 1, [Ag3(bhepH)8(W11.5Na0.5O40P)2]·8H2O (bhep = N,N′-bis(2-hydroxyethyl)piperazine); 2, [Ag4(DMSO)8(Mo8O26)]n; 3, {Ag3[MnMo6O18{(OCH2)3CNH2}2(DMSO)5]·3(DMSO)}n; 4, {Ag3[MnMo6O18{(OCH2)3CNH2}2(DMSO)6(CH3CN)2]·DMSO}n. The compounds were characterised using single crystal X-ray crystallography, elemental analysis, IR, TGA, DSC, and compounds 2–4 were imaged on silicon substrates using scanning electron microscopy. Compound 1 represents a 0D dimer connected by silver ions but was also found to form channels facilitated by the hydrogen bonding between the protonated [bhepH]+ ligand and the cluster, and complex 2 forms 2D layered networks, whereas both compounds 3 and 4 form 1D networks; these networks are all connected by Ag(I) ions. Thermal studies show that the stabilities of compounds 2–4 are affected by the linking Ag(I) ions and the DMSO ligands and EM studies on compounds 3 and 4 showed the formation of fibres on silicon substrates.