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  • 1. Rabbani, Faiz
    et al.
    Ajaz, Humayun
    Zimmermann, Iwan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Synthesis, Crystal Structure and Thermal Decomposition of the New Cadmium Selenite Chloride, Cd-4(SeO3)(2)OCl22014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 5, p. e97175-Article in journal (Refereed)
    Abstract [en]

    A synthetic study in the Cd-Se-O-Cl system led to formation of the new oxochloride compound Cd-4(SeO3)(2)OCl2 via solid state reactions. The compound crystallizes in the orthorhombic space group Fmmm with cell parameters a = 7.3610(3) angstrom, b = 15.4936(2) angstrom, c = 17.5603(3) angstrom, Z = 8, S = 0.969, F(000) = 2800, R = 0.0185, R-w = 0.0384. Single crystal X-ray data were collected at 293 K. The crystal structure can be considered as layered and the building units are distorted [Cd(1)O-6] octahedra, distorted [Cd(2)O-8] cubes, irregular [Cd(3)O4Cl2] polyhedra and SeO3E trigonal pyramids. There are two crystallographically unique Cl atoms that both are half occupied. Thermogravimetric studies show that the compound starts to decompose at 500 degrees C. The crystal structure of the new compound is closely related to the previously described compound Cd-4(SeO3)(2)Cl-4(H2O).

  • 2.
    Steiner, Emilie
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Mathew, Renny
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zimmermann, Iwan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Brotin, Thierry
    Edén, Mattias
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Kowalewski, Jozef
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Investigation of chloromethane complexes of cryptophane-A analogue with butoxy groups using C-13 NMR in the solid state and solution along with single crystal X-ray diffraction2015In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 53, no 8, p. 596-602Article in journal (Refereed)
    Abstract [en]

    Host-guest complexes between cryptophane-A analogue with butoxy groups (cryptophane-But) and chloromethanes (chloroform, dichloromethane) were investigated in the solid state by means of magic-angle spinning C-13 NMR spectroscopy. The separated local fields method with C-13-H-1 dipolar recoupling was used to determine the residual dipolar coupling for the guest molecules encaged in the host cavity. In the case of chloroform guest, the residual dipolar interaction was estimated to be about 19kHz, consistent with a strongly restricted mobility of the guest in the cavity, while no residual interaction was observed for encaged dichloromethane. In order to rationalize this unexpected result, we performed single crystal X-ray diffraction studies, which confirmed that both guest molecules indeed were present inside the cryptophane cavity, with a certain level of disorder. To improve the insight in the dynamics, we performed a C-13 NMR spin-lattice relaxation study for the dichloromethane guest in solution. The system was characterized by chemical exchange, which was slow on the chemical shift time scale but fast with respect to the relaxation rates. Despite these disadvantageous conditions, we demonstrated that the data could be analyzed and that the results were consistent with an isotropic reorientation of dichloromethane within the cryptophane cavity.

  • 3.
    Zimmermann, Iwan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    The Role of Tetrahedral Building Blocks in Low-Dimensional Oxohalide Materials2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The structural architecture found in low-dimensional materials can lead to a number of interesting physical properties including anisotropic conductivity, magnetic frustration and non-linear optical properties. There is no standard synthesis concept described thus far to apply when searching for new low-dimensional compounds, and therefore control on the design of the new materials is of great importance.This thesis describes the synthesis, crystal structure and characterization of some new transition metal oxohalide compounds containing p-elements having a stereochemically active lone-pair. First row transition metal cations have been used in combination with SeIV, SbIII and TeIV ions as lone-pair elements and Cl- and Br- as halide ions. The lone-pairs do not participate in covalent bonding and are responsible for an asymmetric one-sided coordination. Lone-pair elements in combination with halide ions have shown to be powerful structural spacers that can confine transition metal building blocks into low-dimensional arrangements. The halide ions and lone-pairs reside in non-bonded crystal volumes where they interact through weak van der Waals forces. The transition metal atoms are most often arranged to form sheets, chains or small clusters; most commonly layered compounds are formed.To further explore the chemical system and to separate the transition metal entities even more the possibility to include tetrahedral building blocks such as phosphate-, silicate-, sulphate- and vanadate building blocks into this class of compounds has been investigated. Tetrahedral building blocks are well known for their ability of segmenting structural arrangements by corner sharing, which often leads to the formation of open framework structures. The inclusion of tetrahedral building blocks led to the discovery of interesting structural features such as complex hydrogen bonding, formation of unusual solid solutions or faulted stacking of layers.Compounds for which phase pure material could be synthesized have been characterized in terms of their magnetic properties. Most compounds were found to have antiferromagnetic spin interactions and indications of magnetic frustration could be observed in some of them.

  • 4.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Corgnet, Alexis
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Lidin, Sven
    Synthesis and crystal structure of a series of incommensurately modulated composite oxohalide compounds2014In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 43, no 42, p. 15812-15817Article in journal (Refereed)
    Abstract [en]

    Transparent, needle-like single crystals of the isostructural compounds [Sb4O7+3 delta X4][Zn-3](1+delta) = CL Br, I) delta approximate to 0.2 were obtained from chemical reactions in evacuated and sealed silica tubes. First, the average structure was solved in P211n but the model refined poorly and a lowering of the symmetry to the 3 + 1 dimensional space group P2(1)(alpha 0 gamma)0 gave a significantly better fit to the data. This model used second order positional modulations for all the atoms. Whereas Sb, Cl (Br, I) and most 0 positions were well behaved, there was a mismatch with Zn that was better described in a sub-cell, thus yielding a composite structure. The composite nature of the structure leads to a charge imbalance that is compensated by oxygen vacancies.

  • 5.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    A Synthetic Route toward Layered Materials: Introducing Stereochemically Active Lone-Pairs into Transition Metal Oxohalides2014In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 14, no 10, p. 5252-5259Article in journal (Refereed)
    Abstract [en]

    The synthesis and crystal structure of eight new layered compounds in the (Mn2+, Fe2+)-(Sb3+, Te4+)-O-(Cl, Br) system are presented. Mn5Te4O12Cl2 (1), MnSb4O6Cl2 (2), Mn2Sb3O6Cl (3), Mn9Sb8O16Cl10 (4), Fe3Sb2O4Br4 (5), Fe7Sb10O18X8 [X = Cl (6), Br (7)], and Mn7Sb10O18Br8 (8). All of the compounds are made up of charge neutral layers held together through van der Waals interactions, except for compound 2, which has positively charged layers with halide ions between them that act as counterions. The transition metal atoms are confined in sheets within the layers and are thus well separated from each other along the stacking direction. The synthesis concept is based on utilizing both halide ions and p-elements having a stereochemically active lone pair that both act to open up crystal structures. This combination has proven to be a successful synthetic approach for finding new layered inorganic materials containing transition metals.

  • 6.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Stacking faults in a layered cobalt tellurium phosphate oxochlorideManuscript (preprint) (Other academic)
  • 7.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Stacking faults in a layered cobalt tellurium phosphate oxochloride2015In: Solid State Sciences, ISSN 1293-2558, E-ISSN 1873-3085, Vol. 40, p. 67-70Article in journal (Refereed)
    Abstract [en]

    The new compound Co2Te3(PO4)O6Cl was synthesized by chemical reactions in a sealed and evacuated silica tube. The crystal structure was solved from single crystal diffraction data and is made up by charge neutral layers. Within the layers two types of chains are made up by edge sharing [CoO6] and [CoO5Cl] polyhedra respectively. The chains are separated by tellurium oxide and phosphate building blocks. There are only weak Van der Waals interactions in between the layers and severe diffuse scattering is observed due to faulted stacking of the layers. Structure solutions in a P-1 triclinic cell and a larger monoclinic cell in P2(1)/c are discussed and compared to a computer generated model. The reasons for the stacking faults may be due to that there are two positions available for each layer that results in similar connectivity to the next layer in addition to the relatively wide channels in between the layers that reduce the Van der Waals interactions in between them.

  • 8.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Synthesis and Crystal Structure of Mn3(Sb2O2)(VO4)2-x(SbO3)xCl2 (0.08<x<0.13), a vanadium oxochloride with a VV–SbIII split positionManuscript (preprint) (Other academic)
  • 9.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Synthesis and Crystal Structure of the Iron(III) Oxotellurate(IV) Phosphate Oxide Chloride Fe11(TeO3)2(TeO4)3(PO4)2O4Cl32014In: Zeitschrift für Anorganische und Allgemeines Chemie, ISSN 0044-2313, E-ISSN 1521-3749, Vol. 640, no 12-13, p. 2435-2438Article in journal (Refereed)
    Abstract [en]

    The new compound Fe11(TeO3)2(TeO4)3(PO4)2O4Cl3 containing FeIII and TeIV crystallizes in the monoclinic space group C2/c with the unit cell parameters a = 20.5816(5) Å, b = 26.7506(6) Å, c = 5.03910(10) Å, β = 93.587(2)o, Z = 4. Single crystals were grown in sealed and evacuated silica tubes at 550 °C. The compound exhibits an open framework structure built from [FeO6], [FeO5Cl], [FeO4Cl], [PO4], [TeO3], and [TeO4] polyhedra. The TeIV atoms adopt a one sided asymmetric coordination due to the stereochemically active lone-pair. The lone-pairs together with the chloride ions are excluded from the covalently bonded space and protrude into cavities extending along [001]. Bond valence sum calculations confirm iron to be in its FeIII state and the chloride ions to be underbonded and act more as counterions than being fully integrated in the covalent network.

  • 10.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Synthesis and Crystal Structure of the Solid Solution Co-3(SeO3)(3-x)(PO3OH)(x)(H2O) Involving Crystallographic Split Positions of Se4+ and P5+2013In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 52, no 20, p. 11792-11797Article in journal (Refereed)
    Abstract [en]

    Three new cobalt selenite hydroxo-phosphates laying in the solid solution Co-3(SeO3)(3-x)(PO3OH)(x)(H2O), with x = 0.8, x = 1.0, and x = 1.2 are reported. Single crystals were obtained by hydrothermal synthesis and the crystal structure was determined by single crystal X-ray diffraction. The structure can be described as a 3D framework having selenite and hydroxo-phosphate groups protruding into channels in the crystal structure. Se4+ and P5+ share a split position in the structure so that either SeO3 groups having a stereochemically active lone pair or tetrahedrally coordinated PO3OH groups are present. The OH-group is thus only present when the split position is occupied by P5+. The crystal water is coordinated to a cobalt atom and TG and IR measurements show that the water and hydroxyl groups leave the structure at unusually high temperatures (>450 degrees C). Magnetic susceptibility measurements show antiferromagnetic coupling below 16 K and a magnetic moment of 4.02(3) mu(B) per Co atom was observed.

  • 11.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Lidin, Sven
    Crystalline Iron Oxohalide Nanotube Pea Pods2012In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 25, p. 3971-3974Article in journal (Refereed)
    Abstract [en]

    Compounds Fe7Sb3(PO4)3O6Cl3 and Fe7Sb3(PO4)3O6Br3 are the first iron phosphates containing SbIII. They were synthesized by chemical vapor transport reactions, and their crystal structures were characterized by single-crystal X-ray diffraction. The compounds are isostructural and crystallize in the orthorhombic space group Pnma. Tubular Fe7(PO4)3O6X3 units (X = Cl, Br) are linked by SbO4 groups to build up a framework. The tubular units consist of an outer part made up of [FeO5X] octahedra where the Fe atoms are arranged to resemble a nanotube. Inside the tubes there are phosphate groups, and at the very center there is a chain of face-sharing [FeO6] octahedra.

  • 12.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Kremer, Reinhard K.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Synthesis, crystal structure and magnetic properties of a new antimony sulphate oxide CuSb6(SO4)2O8Manuscript (preprint) (Other academic)
  • 13.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Kremer, Reinhard K.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Synthesis, crystal structure and magnetic properties of the open framework compound Co3Te2O2(PO4)2(OH)42011In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 184, no 11, p. 3080-3084Article in journal (Refereed)
    Abstract [en]

    The new compound Co(3)Te(2)O(2)(PO(4))(2)(OH)(4) was synthesized using hydrothermal techniques. It crystallizes in the monoclinic space group C2/m with the unit cell a=19.4317(10) angstrom, b=6.0249(3) angstrom, c=4.7788(2) angstrom, beta=103.139(5)degrees. The crystal structure is an open framework having chains of edge sharing [Co(1)O(6)] octahedra. Other building blocks are [TeO(3)(OH)(2)], [PO(4)] and [Co((2))O(2)(OH)(4)] connected mainly via corner sharing. The -OH groups protrude into channels in the structure. The magnetic susceptibility measured from 2 to 300 K shows two broad anomalies at around 21 K and 4 K. respectively. The peak at similar to 20 K is ascribed to a two-dimensional antiferromagnetic ordering of linear [Co(1)O(6)] chains coupled by interchain interaction via [PO(4)] groups in the Co(1) sheets. The second transition at 4 K is ascribed to a second antiferromagnetic ordering of the moments of the Co(2) entities via super-super exchange involving [PO(4)] and [TeO(3)(OH)(2)] groups. This assignment is strongly supported by low-temperature heat capacity measurements indicating an entropy removal within the high-temperature transition of about twice the magnitude of the low-temperature transition.

  • 14.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Kremer, Reinhard K.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Two isostructural layered oxohalide compounds containing Mn2+, Te4+ and Si4+; crystal structure and magnetic susceptibility2014In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 218, p. 6-9Article in journal (Refereed)
    Abstract [en]

    The new compounds Mn-4(TeO3)(SiO4)X-2 (X=Br, Cl) were synthesized by solid state reactions in sealed evacuated silica tubes. The compounds crystallize in the monoclinic space group P2(1)/m with the unit cell parameters a=5.5463(3) angstrom (5.49434(7) angstrom), b= 6.4893(4) angstrom (6.44184(9) angstrom), c=12.8709(7) A (12.60451 (18) angstrom), beta=93.559(5)degrees (94.1590(12)degrees) and Z=2 for the respective Br and Cl analogues. Manganese adopts various distorted coordination polyhedra; [MnO6] octahedra, [MnO5] tetragonal pyramids and [MnO2X2] tetrahedra. Other building blocks are [SiO4] tetrahedra and [TeO3] trigonal pyramids. The structure is made up from layers having no net charge that are connected via weak Van der Waal interactions. The layers that are parallel to (1 1 0) consist of two manganese oxide sheets which are separated by [Siad tetrahedra. On the outer sides of the sheets are the [MnO2X2] tetrahedra and the [TeO3] trigonal pyramids connected so that the halide ions and the stereochemically active lone pairs on the tellurium atoms protrude from the layers. Magnetic susceptibility measurements reveal a Curie law with a Weiss temperature of theta=-153(3) K for temperatures >= 100 K and indicate antiferromagnetic ordering at TN similar to 4 K. Possible structural origins of the large frustration parameter of f=38 are discussed.

  • 15.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Kremer, Reinhard K.
    Reuvekamp, Patrick
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Crystal structure and magnetic properties of Cr3Te5O13Cl32013In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 42, no 24, p. 8815-8819Article in journal (Refereed)
    Abstract [en]

    A new chromium tellurite oxochloride, Cr3Te5O13Cl3, has been prepared by solid-state reaction and the crystal structure was determined by single crystal X-ray diffraction. The compound crystallizes in the non-centrosymmetric space group P2(1)2(1)2(1) with the unit cell a = 4.90180(10) angstrom, b = 17.3394(2) angstrom, c = 17.5405(2) angstrom, Z = 4, R-1 = 0.0282. The Cr3+ ions have octahedral [CrO6] oxygen coordination, the Te4+ ions have one sided [TeO3] and [TeO3Cl] coordinations. The [CrO6] octahedra are edge sharing and form chains extending along [100]. These are connected by corner sharing [TeO3] and [TeO3Cl] groups to form layers parallel to (110). The layers are connected by weak interactions in between Te4+ in the layers and Cl- ions located in between. The compound undergoes antiferromagnetic ordering at similar to 34 K with a Weiss constant of -230 K. Isothermal magnetization measurements reveal a critical field of about 0.25 T above which the magnetization versus field changes from linear to a Brillouin-like saturation behaviour. The frustration ratio amounts to similar to 6.8 indicative of sizable competing antiferromagnetic spin-exchange interaction. The dielectric constant epsilon (6 kHz) amounts to similar to 7.9 and decreases by about 1% on cooling from 50 K to liquid helium temperatures.

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