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We report here the straightforward synthesis and characterisation of a series Anderson-type hybrid polyoxometalates in high yield, functionalised with carboxylic acid following the reaction of anhydride precursors with the starting hybrid cluster ([n-N(C4H9)4]3[MnMo6O18((OCH2)3CNH2)2]). Seven new structures have been obtained, five of which have acid-terminated ligands. Six of these structures have been isolated with a yield higher than 80% with high purity. This reaction is limited by the bulkiness of the anhydride used; this effect can be employed to selectively synthesise one isomer out of three other possibilities. The acid groups and aromatic platforms attached to the clusters can act as building tools to bridge several length scales and engineer molecular packing within the crystal structure. The presence of acids should also change the hydrophilicity of the clusters, and therefore the way they interact with hydrophilic surfaces. We also show a potential relationship between the acid group interaction in the packing diagram and the cluster's tendency to interact with a hydrophilic surface. In addition to reporting a derived synthetic path to new acid-terminated Mn-Anderson-type hybrids, we describe here a new way to program self-assembly motifs of these compounds in the crystal structure and at interfaces.

The assembly of polyoxometalate architectures based on Mn-Anderson clusters capped with different aromatic platforms via the ‘Tris’ linker (Tris = tris(hydroxymethyl)aminomethane), allows the formation and isolation of four new hybrid polyoxometalate clusters of 2–5 with the general composition of [n-N(C4H9)4]3[MnMo6O18{(OCH2)3CN = CH-R}2]·solv., (R = –(C6H5) 2, –(C6H5O) 3, –(C11H8N) 4 and –(C13H9) 5; solv. = MeOH or H2O). These compounds were obtained simply by the reaction of compound 1, ([n–N(C4H9)4]3[MnMo6O18{(OCH2)3CNH2}2]), with the corresponding aldehyde and the aromatic platforms were chosen to explore the design principles for covalently constructed POM aromatic–organic–inorganic hybrids.

Two cyclic cobalt-substituted heteropolyoxometalates K15Li5[Co10(H2O)34(P8W48O184)]·54H2O (1) and K8Li12[Co10(H2O)44(P8W48O184)]·60H2O (2) have been synthesised from the reaction of Co(II) ions and the superlacunary {P8W48} polyanion in mildly acidic aqueous media. The cluster's anion cavities are filled with Co(II) and K cations and careful manipulation of reaction conditions determines the formation of distinct Co-linked frameworks.

We have used Raman and IR spectroscopy to study the oxidation reaction of sulfite groups in the unique polyoxometalate compound K7Na[WVI18O56(SO3)2(H2O)2]·20H2O with a structure related to the Wells–Dawson type in situ at high temperature and high pressure. The results give new insights into the unusual redox process that occurs in this compound with electrons and O2− ions transferred between the polyoxometalate cluster and SO32−/SO42− groups held within the cage in a process that has been termed the “Trojan Horse” effect.

We present two new ligands, 2,3-dihydro-1-(2-pyridyl-methyl)-imidazo[1,2-f]phenanthridinium bromide (L1·Br) and 2,3-dihydro-1-(4-pyridyl-methyl)-imidazo[1,2-f]phenanthridinium bromide (L2·Br), which have been synthesized and fully characterized as coordinating cations. The reactions of Cu(BF4)2 (compound 1), Cu(NO3)2 (compound 2), CuBr2 (compound 3), Cu(NO3)2 and NaN3 (compound 4), Cu(NO3)2 and NaSCN (compound 5) with L1·Br and CuBr2 with L2·Br (compound 6) have been carried out. The crystal structures of the resulting metal–organic assemblies have been determined and the intermolecular interactions of the compounds in the crystalline phase have been analysed. A mononuclear copper(II) compound has been obtained with CuBr2, in which the copper(II) ion adopts a tetrahedral geometry with a CuNBr3 coordination motif. With Cu(BF4)2, two L1+ cations and two bromide anions chelate the copper ion giving a CuN2Br2 motif, while the BF4− is present as a non-coordinating counterion. With Cu(NO3)2, a five coordinated copper complex is obtained whereas when bridging ligands such as NaN3 and NaSCN are added into the reaction mixture of L1·Br and Cu(NO3)2, two novel dinuclear copper coordination cores of [Cu2(μ1,1-N3)2(N3)4]2− and Cu(CH3O)2(SCN)4]2− form. The presence of the large heteroaromatic cationic DIP moiety within the ligand system leads to the formation of 1-, 2- and 3-D supramolecular arrays based on the interactions of the π systems between adjacent molecules.

The synthesis and structural characterization of three new polyoxomolybdenum(V) phosphate frameworks have been achieved by using dimeric {Mo6}2 moieties as inorganic building blocks and protonated organic amines as counter ions. The structure-directing role of the organic cations was investigated and it was shown, that the geometry and the rigidity of the amines as well as their hydrogen bonding capabilities influence the formation of layered or chain-like superstructures.

The crystal structures of cis,trans-1,3,5-tris-benzaldimino-cyclohexane (trans-tbc, 1), cis,trans-1,3,5-tris-(pyridine-2-carboxaldimino)-cyclohexane (trans-ttop, 2), cis,cis-1,3,5-tris-(pyridine-3-carboxaldimino)-cyclohexane (cis-mttop, 3) and cis,trans-1,3,5-tris-(pyridine-4-carboxaldimino)-cyclohexane (trans-pttop, 4) are reported. The arrangements of the molecules forming the packed arrays are controlled by the interplay of several different weak intermolecular interactions: π–π stacking, C–H⋯π and C–H⋯N interactions, and these are in turn related to differences in the stereochemistry around the cyclohexane backbone, as well as the positioning of the pyridyl–nitrogen to determine the overall supramolecular arrangement of these molecules in the solid state.