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Abstract: The crystal and magnetic structures of the hybrid organic–inorganic layer compound Fe[(CD3PO3)(D2O)] have been studied by neutron powder diffraction as a function of temperature down to 1.5K. The neutron diffraction pattern recorded at 200K shows that the fully deuterated compound crystallizes in one of the two known forms of the undeuterated Fe[(CH3PO3)(H2O)]. The crystal structure is orthorhombic, space group Pmn21, with the following unit-cell parameters: a=5.7095(1)Å, b=8.8053(3)Å and c=4.7987(1)Å; Z=2. The crystal structure remains unchanged on cooling from 200 to 1.5K. Moreover, at low temperature, Fe[(CD3PO3)(D2O)] shows a commensurate magnetic structure (k=(0,0,0)). As revealed by bulk susceptibility measurements on Fe[(CH3PO3)(H2O)], the magnetic structure corresponds to a canted antiferromagnet with a critical temperature T N=25K. Neutron powder diffraction reveals that below T N=23.5K the iron magnetic moments in Fe[(CD3PO3)(D2O)] are antiferromagnetically coupled and oriented along the b-axis, perpendicular to the inorganic layers. No ferromagnetic component is observable in the neutron powder diffraction experiment, due to its too small value (<0.1μ B). [Copyright &y& Elsevier]

Abstract: A second form of the literature-known layered weak ferromagnet Fe[(CH3PO3)(H2O)] has been isolated. The crystal structure determination of this new form (2) has been carried out at , 200 and 130K. It crystallizes in the orthorhombic space group Pmn21: , , , while form (1) crystallizes in the space group Pna21: , , . Mössbauer spectroscopy on form (2) has been performed in the temperature range 4–300K; and, at , a drastic change in the quadrupole splitting (ΔE) and a broadening of the doublet components is noticed. But surprisingly, on cooling the crystal, no structural change is observed, which could account for the increase in . Below , 57Fe spectra transform into hyperfine splitting patterns which reveal a magnetically ordered state in agreement with the results of earlier magnetic susceptibility studies. [Copyright &y& Elsevier]

The new compound MnSbS2Cl was synthesised from a mixture of MnS, MnCl2 and Sb2S3 at 500 °C. Single crystal study indicates orthorhombic symmetry, space group Pnma (No. 62), with , , , and . The refinement converged to and for 742 unique reflections and 32 parameters. The crystal structure of MnSbS2Cl is isotypic with stibnite Sb2S3 and consists of waved layers of corner-sharing MnS4Cl2 octahedra along the a axis and edge-sharing octahedra along the b axis, which are separated by antimony atoms. MnSbS2Cl susceptibility shows an antiferromagnetic behaviour below 40 K with an increase at about 23 K. [Copyright &y& Elsevier]

Abstract: Jamesonite, Fe2+Pb4Sb6S14, is a natural sulfide in which Fe octahedra form single chains, that would favor a quasi-one-dimensional magnetism. The susceptibility shows an antiferromagnetic behavior with a broad maximum at 30K and an irregularity at 5K. A neutron powder diffraction study has been undertaken between 1.4 and 44K. In the diffractograms, below 5K, supplementary peaks of magnetic origin and characteristic of a three-dimensional long-range magnetic ordering appear. The magnetic structure corresponds to a canted antiferromagnet with a propagation wave-vector and a magnetic ordered magnetic moment on Fe atoms of 3.3(1)μB at 1.4K. Below 30K one-dimensional magnetic ordering or correlations are visible in the diagrams and persist down to 1.4K. [Copyright &y& Elsevier]

Pure manganese benavidesite (MnPb4Sb6S14) has been synthesized from a solid state reaction of MnS, PbS and Sb2S3 at 600 °C, and its crystal structure determined. Benavidesite is isotypic of natural jamesonite (FePb4Sb6S14), for which a new structure refinement was performed. Both compounds crystallize in the monoclinic symmetry, space group P21/c (No. 14), with unit cell parameters (jamesonite/benavidesite) a=4.0235/4.0216, b=19.074/19.178, c=15.737/15.837 A˚ and β=91.89/91.89°, Z=2. The projection of the structure along a shows rods (Pb4Sb6S14)∞ parallel to a, connected along c by iron/manganese atoms with octahedral coordination. Octahedra are connected by two opposite edges, forming single chains parallel to a. Magnetic properties have been studied. Jamesonite susceptibility shows an antiferromagnetic behavior below 30 K with an irregularity at about 5 K. Above 30 K, benavidesite and jamesonite have the same behavior but, at low temperature, benavidesite exhibits a paramagnetic behavior. [Copyright &y& Elsevier]

Abstract: The crystal structure of Pb2SbS2I3 was solved at room temperature and 100K. At 293K it crystallizes in the orthorhombic system, space group Cmcm (No. 63), with unit cell parameters a =4.3262(9), b =14.181(3), c =16.556(3)Å, V =1017.7(4)Å3, Z =4. The structure is disordered, and combines a split Pb site (s.o.f.=0.50) with one mixed (Pb,Sb) site with Pb and Sb in two distinct sub-positions. At 100K, it is monoclinic, space group P21/c, with unit cell parameters a =7.3629(6), b =16.466(3), c =8.5939(7)Å, β =107.14(2)°, V =995.6(2)Å3, Z =4. The structure is now fully ordered, without mixed sites. On the basis of bond valence calculations, new cation distributions are proposed for published structures of the Sn isotypes, Sn2SbS2I3 and Sn2SbSe2I3. A re-examination of the crystal structures of various (Pb/Sn/Sb) chalcogeno-iodides is presented according to modular analysis. All these structures can be described according to three types of 1D modules, (Pb/Sn)I4, (Sn)2I4 and (Pb/Sn/Sb)4(S/Se)2I4. Generally each type of 1D module gives one type of slab, and the final structure corresponds to a specific stacking of two or three among these slabs. A new structural model is proposed for “α-Sn2SI2”, which would have the non-stoichiometric composition (Sn5.42□0.58)S2(I6.87□0.12), ideally Sn27S10I34, with probably a narrow solid solution field on the SnS–SnI2 joint. [Copyright &y& Elsevier]

Abstract: The new oxy-chloro-sulfide (Mn1− x Pb x )Pb10+ y Sb12− y S26− y Cl4+ y O (x ∈ [0.2–0.3]; y ∈ [0.3–1.6]) was synthesized by dry way at 500–600°C. A single crystal ∼Mn0.7Pb11.0Sb11.3S25.3Cl4.7O indicates a monoclinic symmetry, space group C2/m, with a = 37.480(8), b = 4.1178(8), c = 18.167(4)Å, β = 106.37(3)°, V = 2690.2(9)Å3, Z = 2. Its crystal structure was determined by X-ray single crystal diffraction, with a final R = 5.11%. Modular analysis of the crystal structure reveals a “waffle” architecture, where complex rods with lozenge section delimitate an internal channel filled by a single chain of (Mn0.7Pb0.3)Cl6 octahedra connected by opposite edges. Minimal inter-chain distances are close to 18Å. The rod wall, two-atom thick, presents, in alternation with S atoms, Pb or (Pb,Sb) cations with prismatic coordination in the internal atom layer, while the external atom layer is constituted exclusively by Sb cations with dissymmetric square pyramidal coordination. A (Pb,Sb)2S2 fragment connects two successive rods along (201) to form a waffle-type palissadic layer. The unique O position, half filled, presents the same environment than the isolated O positions in the oxy-sulfide Pb14Sb30S54O5, or oxy-chloro-sulfides Pb18Sb20S46Cl2O and (Cu,Ag)2Pb21Sb23S55ClO. This compound belongs to a pseudo-homologous series of chalcogenides with waffle structure, ordered according to the size of their lozenge shape channel. Such a complex senary compound of the oxy-chloro-sulfide type illustrates the structural competition between three cations, on one hand, and, on the other hand, three anions. This compound is of special interest regarding the 1D distribution of magnetic Mn2+ atoms at the ∼2nm scale. [Copyright &y& Elsevier]

Abstract: Four new compounds, MnSbS2Br, MnBiSe2Br and two allotropic forms of MnSbSe2Br, were synthesized by solid state reaction at 500–600 °C. Their crystal structures were determined by single crystal X-ray diffraction. MnSbS2Br, isotypic with MnSbSe2I, is monoclinic, space group (No 12), with unit cell parameters , , , , , , . MnBiSe2Br and one form of MnSbSe2Br, isotypic with MnSbS2Cl, are orthorhombic, space group Pnma (No 62), with unit cell parameters , , , , , , respectively. MnSbSe2Br presents a second allotropic form, orthorhombic, space group Pbam (No 55), with , , , , , . This last structure is a 1:1 combination of the two previous types. The crystal chemistry of the Mn family is discussed, and its structural types compared with similar (FeUS3) or homologous derivatives (pavonite series). [Copyright &y& Elsevier]

Abstract: Fe[(CH3(CH2)2PO3)(H2O)] (1) and Fe[(CH3(CH2)17PO3)(H2O)] (2) were synthesized by reaction of FeCl2·6H2O and the relevant phosphonic acid in water in presence of urea and under inert atmosphere. The compounds were characterized by elemental and thermogravimetric analyses, UV–visible and IR spectroscopy. The crystal structure of (1) was determined from X-ray single crystal diffraction studies at room temperature: monoclinic symmetry, space group P21, , , , and . The compound is lamellar and the structure is hybrid, made of alternating inorganic and organic layers along the c direction. The inorganic layers consist of Fe(II) ions octahedrally coordinated by five phosphonate oxygen atoms and one from the water molecule, separated by bi-layers of propyl groups. A preliminary structure characterization of compound (2) suggests a similar layered structure, but with an interlayer spacing of 40.3Å. The magnetic properties of the compounds were both studied by a dc and ac SQUID magnetometer. Fe[(CH3(CH2)2PO3)(H2O)] (1) obeys the Curie–Weiss law at temperatures above 50K (, ), indicating a Fe +II oxidation state, a high-spin d 6 () electronic configuration and an antiferromagnetic exchange couplings between the near-neighbouring Fe(II) ions. Below , Fe[(CH3(CH2)2PO3)(H2O)] exhibits a weak ferromagnetism. The critical temperature of has been determined by ac magnetic susceptibility measurements. Compound (2) shows the same paramagnetic behaviour of the iron (II) propyl derivative. The values of C and θ were found to be and −44K, respectively, thus suggesting the presence of Fe +II ion in the spin state and antiferromagnetic interactions between Fe(II) ions at low temperatures. Zero-field and field cooled magnetic susceptibility vs. T plots do not overlap below , suggesting the presence of an ordered magnetic state. The critical temperature, , has been located by the peaks at from the ac susceptibility (χ′and χ″) vs. T plots. Below hysteresis loops recorded in the temperature region show an S-shape, while below 15K assume an ellipsoid form. They reveal that compound (2) is a weak ferromagnet. The critical temperature in these layered Fe(II) alkylphosphonates is independent of the distance between the inorganic layers. [Copyright &y& Elsevier]

Abstract: Among the MnPnQ 2 X compounds (Pn: pnictide; Q: chalcogen; X: halogen), two isotypic chloro-sulfides, MnSbS2Cl and MnBiS2Cl, have been studied. MnBiS2Cl is a new compound synthesized by solid state reaction at 500°C. It is orthorhombic, space group Pnma, with , , , , . Its X-ray single crystal study shows (001) waved layers of MnS4Cl2 octahedra, opposite edge-sharing along , and corner-sharing along . Similar magnetic susceptibilities for both compounds have been recorded, indicating high spin Mn2+ with anti-ferromagnetic exchange. Correlatively, specific heat versus temperature shows a magnetic transition at for the Sb-bearing compound, and a two-steps magnetic transition at 28 and 32K for the Bi isotype. The magnetic structure of MnSbS2Cl has been determined by neutron diffraction, revealing a magnetic ordering at 1.5K with an incommensurate wave-vector along (k=[0, 0.3838, 0]). Two modulation models, sinusoidal and helicoidal, give quite equivalent reliability factors ( and 0.0586, respectively). [Copyright &y& Elsevier]

Synthesis, crystal structure of two new ABTS (2,2-azinobis-3-ethyl benzothiazoline-6-sulfonate) hybrid organic–inorganic salts containing Fe3+ or Cu2+ cations is described. Electrochemical oxidation of the diammonium salt (ABTS)(NH4)2·2H2O in presence of FeSO4·7H2O or CuSO4·5H2O in aqueous solutions yields to black single crystals of Fe2O(ABTS)2(H2O)16 and Cu(ABTS)2·(H2O)8. Due to the low thermal stability of three water molecules intercalated in the network, crystal structures were solved at 200 K using a STOE IPDS diffractometer. Cell parameters are: a=8.5635(7) A˚, b=8.69236(6) A˚, c=20.336(2) A˚, α=84.69(1)°, β=82.10(1)°, γ=81.767(9)°, space group P-1 for the iron complex and a=15.691(3) A˚, b=14.474(3) A˚, c=21.552(4) A˚, β=94.60(3)°, space group P21/c for the copper complex. Transition metal cations are in an octahedral coordination with a different condensation, corner-sharing octahedra Fe2O11 dimmers or CuO6 octahedra. Taking in account these structural results, the chemical formula must be written: [Fe2O(H2O)10][ABTS]2·6H2O and [Cu(H2O)5][ABTS]2·3H2O. The crystalline networks are also different; the iron complex salt presents a bidimensional character and the copper one can be considered as a one-dimensional network. Values obtained from bond valence calculations correspond to iron Fe3+ and copper Cu2+. A Mossbauer study shows that iron is in a high spin 3+ oxidation state without any magnetic ordering even at 4 K (isomer shift δ=0.62 mm s−1 and quadrupole splitting ΔE=1.64 mm s−1). [Copyright &y& Elsevier]

Hydrotalcite and hydrocalumite are two close minerals belonging to the layered double hydroxide family. Both structures are based on positive brucite-like layers alternating with layers containing anions and water molecules. Most of synthetic (LDHs) are hydrotalcite-like materials. On the other hand, the hydrocalumite structure type is rare for those less broad in composition, typically Ca2+ and Al3+ in the hydroxide layers. In order to get further insight into the conditions of stabilization of this structure type, we have undertaken the synthesis and the structural characterization by powder X-ray diffraction of the series Ca2M3+(OH)6Cl·2H2O(M3+:Al3+, Ga3+, Fe3+ and Sc3+). The incorporation of Sc3+ ions is quite original. All phases crystallize in the rhombohedral space group R-3 resulting in a three-layers polytype. The main consequence of the replacement of Al3+ cations by large M3+ cations is a compression of the octahedral layers like it proceeds in hydrotalcite-like materials. The existence of Sc-containing phase allows us to say that it is the size of Ca2+ ions and the pronounced anisotropy of coordination spheres around Ca2+ and M3+ which are responsible for the ordered distribution of cations in hydrocalumite-like materials. [Copyright &y& Elsevier]

The purpose of this study was to control the fabrication of new labile supramolecular assemblies by formulating associations of DNA molecules with inorganic layered double hydroxides (LDHs). The results show that LDH/DNA hybrids synthesized by a coprecipitation route involving the in situ formation of LDHs around DNA molecules acting as templates were characterized by a lamellar organization, with DNA molecules sandwiched between hydroxide layers, exhibiting a regular spacing of 1.96 nm. Our results indicate that labile complexes resulting from the association of nucleic acids and inorganic materials can be obtained not only by anion exchange but also by a direct self-assembly route.