title: Double salt crystal structure of hexa-sodium hemiundeca-hydrogen α-hexa-molybdoplatinate(IV) heminona-hydrogen α-hexa-molybdoplatinate(IV) nona-cosa-hydrate: di-hydrogen disordered-mixture double salt.
abstract: The title double salt containing two distinct, differently protonated hexa-molybdoplatinate(IV) polyanions, Na6[H5.5 α-PtMo6O24][H4.5 α-PtMo6O24]·29H2O, has been synthesized by a hydro-thermal reaction at ca pH 1.80. The positions of the H atoms in the polyanions were established from difference Fourier maps and confirmed by the inter-polyanion hydrogen bonds, bond-distance elongation, and bond-valence sum (BVS) calculations. The fractional numbers of H atoms in each polyanion are required for charge balance and in order to avoid unrealistically short H⋯H distances in the inter-polyanion hydrogen bonds. Considering the disorder, the refined formula of the title polyanion, {[H5.5 α-PtMo6O24]; polyanion (A) and [H4.5 α-PtMo6O24]; polyanion (B)}(6-), can be rewritten as a set of real formula, viz. {[H6 α-PtMo6O24]; polyanion (A). [H4 α-PtMo6O24]; polyanion (B)}(6-) and {[H5 α-PtMo6O24]; polyanion (A). [H5 α-PtMo6O24]; polyanion (B)}(6-). The polyanion pairs both form dimers of the same formula, viz. {[H10 α-Pt2Mo12O48]}(6-) connected by seven inter-polyanion O-H⋯O hydrogen bonds.
authors.affiliation: Department of Chemistry, Pukyong National University, 599-1 Daeyeon 3-dong, Nam-gu, Busan 608-737, Republic of Korea.
authors.forename: Hea-Chung
authors.initials: HC
authors.lastname: Joo
authors.affiliation: Research Institute of Natural Science, Gyeongsang National University, 501, Jinju-daero, Jinju, 660-701, Republic of Korea.
authors.forename: Ki-Min
authors.initials: KM
authors.lastname: Park
authors.affiliation: Department of Chemistry, Pukyong National University, 599-1 Daeyeon 3-dong, Nam-gu, Busan 608-737, Republic of Korea.
authors.forename: Uk
authors.initials: U
authors.lastname: Lee
keywords: crystal structure; double salt-type heteropolyoxometalate; hexa­molybdoplatinate(IV); multi­hydrogen bond; platinium containing polyoxomolybdate