title: Controlling the self-assembly of a mixed-metal Mo/V-selenite family of polyoxometalates.
abstract: Five mixed-metal mixed-valence Mo/V polyoxoanions, templated by the pyramidal SeO(3)(2-) heteroanion have been isolated: K(10)[Mo(VI)(12)V(V)(10)O(58)(SeO(3))(8)]⋅18 H(2)O (1), K(7)[Mo(VI)(11)V(V)(5)V(IV)(2)O(52)(SeO(3))]⋅31 H(2)O (2), (NH(4))(7)K(3)[Mo(VI)(11)V(V)(5)V(IV)(2)O(52)(SeO(3))(Mo(V)(6)V(V)-O(22))]⋅40 H(2)O (3), (NH(4))(19)K(3)[Mo(VI)(20)V(V)(12)V(IV)(4)O(99)(SeO(3))(10)]⋅36 H(2)O (4) and [Na(3)(H(2)O)(5){Mo(18-x)V(x)O(52)(SeO(3))} {Mo(9-y)V(y)O(24)(SeO(3))(4)}] (5). All five compounds were characterised by single-crystal X-ray structure analysis, TGA, UV/Vis and FT-IR spectroscopy, redox titrations, and elemental and flame atomic absorption spectroscopy (FAAS) analysis. X-ray studies revealed two novel coordination modes for the selenite anion in compounds 1 and 4 showing η,μ and μ,μ coordination motifs. Compounds 1 and 2 were characterised in solution by using high-resolution ESI-MS. The ESI-MS spectra of these compounds revealed characteristic patterns showing distribution envelopes corresponding to 2- and 3- anionic charge states. Also, the isolation of these compounds shows that it may be possible to direct the self-assembly process of the mixed-metal systems by controlling the interplay between the cation "shrink-wrapping" effect, the non-conventional geometry of the selenite anion and fine adjustment of the experimental variables. Also a detailed IR spectroscopic analysis unveiled a simple way to identify the type of coordination mode of the selenite anions present in POM-based architectures.
authors.affiliation: WestCHEM, School of Chemistry, The University of Glasgow, Scotland, UK.
authors.forename: M Nieves
authors.initials: MN
authors.lastname: Corella-Ochoa
authors.forename: Haralampos N
authors.initials: HN
authors.lastname: Miras
authors.forename: De-Liang
authors.initials: DL
authors.lastname: Long
authors.forename: Leroy
authors.initials: L
authors.lastname: Cronin
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D008968:Molecular Conformation; D008982:Molybdenum / Q000737:chemistry*; D018038:Sodium Selenite / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D017973:Tungsten Compounds / Q000737:chemistry*; D014639:Vanadium / Q000737:chemistry*; D000099294:Polyoxometalates
chemical_list: D056831:Coordination Complexes; D008982:Molybdenum; D018038:Sodium Selenite; D017973:Tungsten Compounds; D014639:Vanadium; C102296:polyoxometalate I; D000099294:Polyoxometalates