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Mats Johnsson

Publications and source records attributed to Mats Johnsson.

10 recordsLinked to original sources
PubMed2006

Monoclinic Cu3(SeO3)2Cl2: an oxohalide with an unusual CuO4Cl trigonal-bipyramidal coordination.

In single crystals of a new monoclinic (C2/m) form of tricopper(II) diselenium(IV) dichloride hexaoxide, Cu3(SeO3)2Cl2, the Se atom is in the 4i position, while the two Cu atoms are in 2a and 4i positions. The structure is based on layers of CuO4Cl trigonal bipyramids, CuO4 square planes and SeO3E tetrahedra. The Cu polyhedra are connected by edge- and corner-sharing to form [010] chains and these chains are bridged by the Se atoms to form (001) layers. The compound is isostructural with Cu3(TeO3)2Br2.

Journal Article↗
PubMed2006

Crystal structure and magnetic properties of FeTe2O5X (X=Cl, Br): a frustrated spin cluster compound with a new Te(IV) coordination polyhedron.

A new layered transition metal oxohalide, FeTe2O5ClxBr1-x, has been identified. It crystallizes in the monoclinic space group P21/c. The unit cell for FeTe2O5Br is a = 13.3964(8), b = 6.5966(4), c = 14.2897(6) A, beta=108.118(6) degrees, and Z=8. The layers are built of edge sharing [FeO6] octahedra forming [Fe4O16]20- units that are linked by [Te4O10X2]6- groups. The layers have no net charge and are only weakly connected via van der Waals forces to adjacent layers. There are four crystallographically different Te atoms, and one of them displays a unique [TeO2X] coordination polyhedron (X=Cl, Br). Magnetic susceptibility measurements show a broad maximum typical for 4-spin clusters of coupled Fe(III) ions in the high-spin state. Evidence for magnetic instabilities exists at low temperatures, which have been confirmed with specific heat experiments. A theoretical modeling of the susceptibility concludes a frustration of the intra-tetramer anti-ferromagnetic exchange interaction.

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PubMed2006

Sr2Cu2TeO6Br2: honeycomb layers of copper(II) ions.

Single crystals of distrontium(II) dicopper(II) tellurium(VI) hexaoxide dibromide, Sr2Cu2TeO6Br2, were synthesized via solid state/gas phase reactions in sealed evacuated silica tubes. The building units are irregular SrO4Br3 polyhedra (a new type of coordination polyhedron around Sr(II)), CuO5 square pyramids and TeO6 octahedra. The CuO5 square pyramids and the TeO6 octahedra together form layers in the bc plane bridged by Sr atoms. The Cu atoms are arranged to form puckered honeycomb layers. The Te atom lies on an inversion centre.

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PubMed2006

MoCu3TeO7Cl2.0.5H2O.

Single crystals of molybdenum(VI) tricopper(II) tellurium(IV) heptaoxide dichloride hemihydrate, MoCu3TeO7Cl2.0.5H2O, were synthesized via a transport reaction in sealed evacuated silica tubes. All atoms occupy general positions within the triclinic (P1) unit cell. The building units are irregular CuO4Cl and CuO3Cl2 square pyramids, distorted TeO3+1E trigonal bipyramids (E is the lone pair of TeIV) and irregular MoO5 pyramids. The TeO3+1E, CuO4Cl and CuO3Cl2 polyhedra form (110) layers bridged by Mo atoms. The water molecules are located in [100] channels.

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PubMed2005

Ca2CuTe4O10Cl2, a new synthetic tellurium(IV) oxochloride.

Single crystals of dicalcium copper tetratellurium decaoxide dichloride, Ca2CuTe4O10Cl2, were synthesized via a transport reaction in sealed evacuated quartz glass tubes. The building units of the structure are irregular CaO7 polyhedra, centrosymmetric CuO4Cl2 octahedra and two crystallographically distinct TeO4E distorted bipyramids (E being the 5s2 lone pair of TeIV). The TeO4E and CuO4Cl2 polyhedra together form planes that are connected by the Ca atoms. The CuO4Cl2 octahedra are isolated from each other by the other building units.

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PubMed2003

A synthetic zinc tellurium oxochloride, Zn2(TeO3)Cl2.

Single crystals of dizinc tellurium dichloride trioxide, Zn(2)(TeO(3))Cl(2), were synthesized via a transport reaction in sealed evacuated glass tubes. The compound has a layered structure in which the building units are [ZnO(4)Cl] square pyramids, distorted [ZnO(2)Cl(2)] tetrahedra and [TeO(3)E] tetrahedra (E is the 5s(2) lone pair of the Te(IV) atom), joined through shared edges and corners to form charge-neutral layers. Cl atoms and Te-atom lone pairs protrude from the surfaces of each layer towards adjacent layers, and the layers are held together by dispersion forces only. The compound is isostructural with the synthetic compound CuZn(TeO(3))Cl(2) and the mineral sophiite, Zn(2)(SeO(3))Cl(2).

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