title: Commensurate (C6H14N2)2[Mo8O26] * 4H2O and incommensurate (C6H14N2)2[Mo8O26] * 4.66H2O: a structural versatility linked to solvent content.
abstract: The syntheses and structure determinations by means of single-crystal X-ray diffraction of commensurate (C(6)H(14)N(2))(2)[Mo(8)O(26)] * 4H(2)O and incommensurate (C(6)H(14)N(2))(2)[Mo(8)O(26)] * 4.66H(2)O, two new organic-inorganic hybrid compounds based on polyoxomolybdates and differing in their solvent content, are reported. Given the important disorder observed in the latter compound, only a combination of non-harmonic waves, crenel functions and TLS tensors offered a good modelling of the structure. (C(6)H(14)N(2))(2)[Mo(8)O(26)] * nH(2)O results from the self-assembly of [Mo(8)O(26)](4-) anionic chains, C(6)H(14)N(2)(2+) (H(2)DABCO(2+)) cations and water molecules. The [Mo(8)O(26)](4-) chain is built from gamma-[Mo(8)O(28)](8-) octamolybdate clusters, connected to each other through corner sharing. In both compounds, the [Mo(8)O(26)](4-) chains are separated, in a similar way, by the H(2)DABCO(2+) subunits, acting as charge-compensating cations, and by the water molecules. The orientation of the H(2)DABCO(2+) cations is shown to be different from what has been observed previously in monoclinic (H(2)DABCO)(2)[Mo(8)O(26)] * 4H(2)O, and therefore to give a different network of hydrogen bonds.
authors.affiliation: Laboratoire de Chimie des Solides, IMN, UMR 6502 CNRS, Université de Nantes, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3, France. michel.evain@cnrs-imn.fr
authors.forename: Michel
authors.initials: M
authors.lastname: Evain
authors.forename: Vaclav
authors.initials: V
authors.lastname: Petricek
authors.forename: Violaine
authors.initials: V
authors.lastname: Coué
authors.forename: Rémi
authors.initials: R
authors.lastname: Dessapt
authors.forename: Martine
authors.initials: M
authors.lastname: Bujoli-Doeuff
authors.forename: Stéphane
authors.initials: S
authors.lastname: Jobic
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D008982:Molybdenum / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D010879:Piperazines / Q000737:chemistry; D012997:Solvents
chemical_list: D009942:Organometallic Compounds; D010879:Piperazines; D012997:Solvents; D008982:Molybdenum; C007306:triethylenediamine