Synthesis and crystal structure of new complex sodium lanthanide phosphate molybdates Na2MIII(MoO4)(PO4)(MIII = Tb, Dy, Ho, Er, Tm, Lu)

New complex sodium lanthanide phosphate molybdates Na₂M^III(MoO₄)(PO₄)(M^III=Tb, Dy, Ho, Er, Tm, Lu) have been synthesized by the ceramic method (T = 600°C, τ = 48 h), and their unit cell parameters have been determined. The structures of Na₂M^III(MoO₄)(PO₄)(M^III = Dy, Ho, Er, Lu) were refined by the Rietveld method. The compounds are isostructural: they are orthorhombic (space group Ibca, Z = 8) and have layered structures. In the structures of phosphate molybdates, chains of M^IIIO₈ polyhedra and MoO₄ tetrahedra are linked by PO₄ tetrahedra to form layers. The MoO ₄ ^2? anions are involved in dipole-dipole interaction. The sodium ions are arranged in the interlayer space. The compounds melt incongruently at 850–870°C.     

Verbindungen des Typs MII3MIII(PO4)3 mit Eulytinstruktur (MII = Pb,Sr, Ba; MIII = La,Lanthanide, Y,Sc, Bi,In, TI)1

A number of new phosphates of the formula M^II₃M^III(PO₄)₃ has been prepared. They have the cubic structure of eulytite (Bi₄(SiO₄)₃). Obviously all combinations of the cations being specified in the title for M^II and M^III seem to be possible; moreover, Ca₃Bi(PO₄)₃ does exist. The ions M^II and M^III are distributed on the positions of Bi in a statistical manner. The peculiar dependence of the lattive constants of the lanthanide compounds Pb₃Ln(PO₄)₃ (including La) on the (Atomic number of the lanthanide ions suggests the conclusion that the small trivalent cations (r < 1 Å) do not have a close contact with the surrounding oxygen ions forming a distorted octahedron.     

Zur Kenntnis des Verhaltens der Oxidsulfate der Seltenen Erden gegen Chlorwasserstoff. II. Charakterisierung und thermisches Verhalten der Umsetzungsprodukte der Oxidsulfate mit Chlorwasserstoff

The reaction products of the oxide sulphates of rare earths with hydrogen chloride are mixtures of chlorides M^IIICl₃ and chloride-sulphates M^IIICl₃ and chloride-sulphates M^IIIClSO₄. By oxidation of these mixtures, oxide sulphates MO₂SO₄ are formed as final products. Intermediary products are mixtures of M^IIIOCl? M^IIIClSO₄.     

Über die Ordnung von BIII und MV in Perowskiten vom Typ ABIIIMVO6 (AII  Ba,Sr; MV  Sb,Nb, Ta)

On the Ordering of B^III and M^V in Perovskites of Type A B^IIIM^VO₆ (A^II ? Ba, Sr; M^V ? Sb, Nb, Ta) The perovskites Ba₂B^IIISbO₆ crystallize monoclinic (B^III ? La, Pr, Nd) and cubic (B^III ? Sm, Eu, Gd, Tb, Dy, Yb, Lu, Y) respectively. The Sr compounds, Sr₂B^IIISbO₆, have a monoclinic (B^III ? Nd, Sm, Eu, Dy), orthorhombic (B^III ? Yb, Lu, Y, Sc) or cubic (B^III ? In, Ga) perovskite structure. By intensity calculations and vibrational spectroscopic investigations deviations from a complete order between B^III and Sb^V are detectable. For perovskites Ba₂B^IIIM^VO₆ with M^V ? Nb, Ta the incompleteness of cationic order can be demonstrated as well.     

Dimethylerdmetall‐Heterocyclen als Derivate trimethylsilylierter, ‐germylierter und ‐stannylierter Phosphane und Arsane – Synthesen,Spektren und Strukturen

Dimethyl Earth‐Metal Heterocycles – Derivatives of Trimethyl‐silylated, ‐germylated, and ‐stannylated Phosphanes and Arsanes – Syntheses, Spectra, and Structures The organo earth‐metal heterocycles [Me₂M^III–E(M^IVMe₃)₂]_n with M^III = Al, Ga, In; E = P, As; M^IV = Si, Ge, Sn and n = 2, 3 (Me = CH₃) have been prepared from the dimethyl metal compounds Me₂M^IIIX (X = Me, H, Cl, OMe, OPh) and the pnicogen derivatives H_nE(M^IVMe₃)_3–n (n = 0, 1) according to known preparation methods. The mass, ¹H, ¹³C, ³¹P, ²⁹Si, ¹¹⁹Sn nmr, as well as the ir and Raman spectra have been discussed comparatively; selected representatives are characterized by X‐ray structure analyses. The dimeric species with four‐membered (E–M^III)₂ rings are isotypic and crystallize in the triclinic space group P1, the trimer [Me₂In–P(SnMe₃)₂]₃ with a strongly puckered (In–P)₃‐ring skeleton crystallizes with two formula units per cell in the same centrosymmetric triclinic space group.     

Preparation and phase relationships in systems of the type CdSMIMIIIS2 where MI = Ag,Cu and MIII = Al,Ga, In

Systems of the type M^IM^IIIS₂ (chalcopyrite)-CdS (wurtzite) where M^I = Ag, Cu and M^III = Al, Ga, In were investigated to determine the regions of mutual solid solubility. It was found that the chalcopyrite structure could not tolerate extensive CdS substitution. When M^III was Al or Ga the solubility of M^IM^IIIS₂ in CdS was also very limited. However, when M^III = In (r_In³⁺ ? r_Ga³⁺ > r_Al³⁺), the solubility of M^IInS₂ in CdS was quite extensive (～50%). These results are consistent with a prior study on systems of the type M^IM^IIIS₂ZnS which indicated that in sulfides, larger cations tend to result in the formation of new quaternary, wurtzite phases.     

Untersuchungen an quaternären Fluoriden LiMIIMIIIF6, Über die Kationenverteilung in Fluortrirutilen

Inhaltsübersicht. Fluortrirutile LiM^IIM^IIIF₆ kristallisieren tetragonal in dor Raumgruppe P4₂/mnm mit Li in Position (2a) und M^II und M^III statistisch vorteilt in (4e). An Einkristallen und durch Pulvermessungen wurde die Verteilung der Kationen untersucht, wozu die neu dargestellte Rhodiumverbindung LiZnRhF₆ auf Grund des unterschiedlichen Streuvermögens der Kationen besonders geeignet war. Verbindungen LiCuM^IIIF₆ zeigen die einfache Rutilstruktur. Investigations of the Quaternary Fluorides LiM^IIM^IIIF₆. On the Distribution of Cations in Fluorotrirutiles Abstract. Trirutiles LiM^IIM^IIIF₆ crystallize tetragonally in the space group P4₂/mnm with Li in position (2a) und M^II and M^III statistically distributed in (4e). By single-crystal X-Ray diffraction and by powder work cation ordering was examined for which the new compound LiZnRhF, was especially adapted. Compounds LiCuM^IIIF₆ are disordered rutile phases.     

Ba3MIIITiMVO9 (MIII = Fe,Ga, Y,Lu; MV = Nb,Ta, Sb) perovskite oxides: Synthesis,structure and dielectric properties

We describe the synthesis, structures and dielectric properties of new perovskite oxides of the formula, Ba₃M^IIITiM^VO₉, for M^III = Fe, Ga, Y, Lu and M^V = Nb, Ta, Sb. While M^V = Nb and Ta oxides adopt disordered/partially ordered 3C perovskite structures where M^III/Ti/M^V metal-oxygen octahedra are corner-connected, the M^V = Sb oxides show a distinct preference for the 6H structure, where Sb^V/Ti^IV metal-oxygen octahedra share a common face forming (Sb,Ti)O₉ dimers that are corner-connected to the M^IIIO₆ octahedra. The preference of antimony oxides (Sb^V:4d¹⁰) for the 6H structure – which arises from a special Sb^V–O chemical bonding that tends to avoid linear Sb–O–Sb linkages unlike Nb^V/Ta^V:d⁰ atoms which prefer ～180° Nb/Ta–O–Nb/Ta linkages – is consistent with the crystal chemistry of M^V–O oxides in general. The dielectric properties reveal a significant difference among M^III members. All the oxides with the 3C structure excepting those with M^III = Fe show a normal low loss dielectric behaviour with ε = 20–60 in the temperature range 50–400 °C; the M^III = Fe members with this structure (M^V = Nb, Ta) display a relaxor-like ferroelectric behaviour with large ε values at frequencies ≤1 MHz (50–500 °C).     

A Pedagogical Illustration of the Determination of the Nature and Strength of Bonds in Crystalline Compounds from X-ray Diffraction and Infrared Spectroscopy Studies

This article describes a method used to teach students how X-ray crystallography and infrared spectroscopy analysis can be used to obtain information about the nature and strength of the bonding in the crystalline compounds M^IM^III(SO₄)₂ (with M^I = K⁺, Rb⁺, Cs⁺ and M^III = Al³⁺, Cr³⁺, Fe³⁺). These sulfates form an isomorphic series. The influences of specific M^IM^III ions on the variation of the a and c parameters and on the position of IR absorption bands are described. Additionally, X-ray crystallography and infrared spectroscopy studies of the double sulfates M^IM^III(SO₄)₂ show students the existence of [SO₄-M^III-SO₄]^– layers in the crystallized products; the covalent character of M^III-O attractions, which give cohesion in these layers; the existence of M^I layers between [SO₄-M^III-SO₄]^– layers, and the electrovalent character of M^I-O interactions.     

Strukturuntersuchungen an Usoviten: Ba2CaMIIV2F14 (MIII = Mn,Fe), Ba2CaMnFe2F14 und Ba2CaCuM2IIIF14 (MIII = Mn,Fe, Ga)

Structural Studies with Usovites: Ba₂CaM^IIV₂F₁₄ (M^III = Mn, Fe), Ba₂CaMnFe₂F₁₄ and Ba₂CaCuM₂^IIIF₁₄ (M^III = Mn, Fe, Ga). Single crystals of six compounds Ba₂CaM^IIM₂^IIIF₁₄ were prepared to refine their usovite type structure (space group C2/c, Z = 4) using X‐ray diffractometer data. The cell parameters of the phases studied with M^IIM₂^III= MnV₂, FeV₂, CuMn₂, MnFe₂, CuFe₂ und CuGa₂ are within the range 1374≤a/pm≤1384, 534≤b/pm≤542, 1474≤c/pm≤1510, 91, 3≤ß/°≤93, 2. The atoms Ca and M^II are incompletely ordered on the 8‐ and 6‐coordinated positions, 4e and 4b, respectively. In the case of Ba₂CaFeV₂F₁₄ and Ba₂CaCuGa₂F₁₄ there is reciprocal substitution (x≈0, 1): (Ca_1‐xM_x^II) (4e) and (M_1‐x^IICa_x) (4b). In the case of the other usovites Ca‐enriched phases Ba₂Ca(M_1‐y^IICa_y)M₂^IIIF₁₄ occured (up to y≈0, 35), exhibiting partial substitution at the octahedral position (4b) only, showing a corresponding increase in M^II‐F distances. The distortion of [M^IIF₆] and [M^IIIF₆] octahedra within the structure is considerably enhanced on replacement by Cu^II and Mn^III. The results of powder magnetic susceptibility measurements of Ba₂CaMnV₂F₁₄ and Ba₂CaFeV₂F₁₄ (T_N≈7K) are reported.     

Synthesis and characterization of phosphates in molten systems Cs2O-P2O5-CaO-M2O3 (M—Al, Fe, Cr)

The crystallization of complex phosphates from the melts of Cs₂O-P₂O₅-CaO-M^III₂O₃ (M^III—Al, Fe, Cr) systems have been investigated at fixed value Cs/P molar ratios equal to 0.7, 1.0 and 1.3 and Са/Р=0.2 and Ca/М^III=1. The fields of crystallization of CsCaP₃O₉, β-Ca₂P₂O₇, Cs₂CaP₂O₇, Cs₃CaFe(P₂O₇)₂, Ca₉M^III(PO₄)₇ (M^III—Fe, Cr), Cs_0.63Ca_9.63Fe_0.37(PO₄)₇ and CsCa₁₀(PO₄)₇ were determined. Obtained phosphates were investigated using powder X-ray diffraction and FTIR spectroscopy. Novel whitlockite-related phases CsCa₁₀(PO₄)₇ and Cs_0.63Ca_9.63Fe_0.37(PO₄)₇ have been characterized by single crystal X-ray diffraction: space group R3c, a=10.5536(5) and 10.5221(4) Å, с=37.2283(19) and 37.2405(17) Å, respectively.     

Gitterkonstanten und Ionenradien für Pyrochlore CsMIIMIIIF6

Lattice Constants and Ionic Radii of Pyrochlores CsM^IIM^IIIF₆ From observed lattice constants a₀ of 30 cubic pyrochlores CsM^IIM^IIIF₆ (M^II = Mg, Ni, Cu, Zn, Co, Mn; M^III = Ga, Cr, Fe, V, Ti) balanced values a_c were calculated, which deviate in average less than 0.1% from the observed ones. Radii r_c of the M(II) and M(III) ions are evaluated from the balanced values a_c by means of an empiric equation; they reproduce the lattice constants a₀ equally well. By analogy derived radii r_II and r_III from additional pyrochlores CsM^IIM^IIIF₆ are given and discussed in comparison with tabulated radii and observed M? F distances.     

A New Domain of Reactivity for High‐Valent Dinuclear [M(μ‐O)2M′] Complexes in Oxidation Reactions

The strikingly different reactivity of a series of homo‐ and heterodinuclear [(M^III)(μ‐O)₂(M^III)′]²⁺ (M=Ni; M′=Fe, Co, Ni and M=M′=Co) complexes with β‐diketiminate ligands in electrophilic and nucleophilic oxidation reactions is reported, and can be correlated to the spectroscopic features of the [(M^III)(μ‐O)₂(M^III)′]²⁺ core. In particular, the unprecedented nucleophilic reactivity of the symmetric [Ni^III(μ‐O)₂Ni^III]²⁺ complex and the decay of the asymmetric [Ni^III(μ‐O)₂Co^III]²⁺ core through aromatic hydroxylation reactions represent a new domain for high‐valent bis(μ‐oxido)dimetal reactivity.     

Die ersten oligomeren Anionen bei Fluoro-Litho-Metallaten mit Oktaeder-Sandwich-Motiv: Cs4K{[F3MIIIF3]Li[F3MIIIF3]}, MIII = Ga,Fe [1]

The First Oligomeric Anions of Fluoro-Litho Metallates with Octahedra Sandwich Motive: Cs₄K{[F₃M^IIIF₃]Li[F₃M^IIIF₃]}, M^III = Ga, Fe Colourless single crystals of Cs₄K{Li[Ga₂F₁₂]} ( A ) and Cs₄K{Li[Fe₂F₁₂]} ( B ) have been obtained by solid state reaction from intimate mixtures of the corresponding binary fluorides (Pt-tube, 750°C, 40 d). The trigonal unit cells with ( A ) a = 631,3(1)pm; c = 3059,9(6)pm and ( B ) a = 635,0(1)pm; c = 3089,2(7)pm, respectively (Z = 3, Guinier-Simon data, Cu-Kα₁), are confirmed by single crystal investigations. The compounds crystalize isostructural in the space group R3 m (No. 166). The structures were determined using four-circle diffractometer data (Siemens AED 2) with ( A ) R = 2.95%, 3627 I_o and ( B ) R = 1.86%, 4179 I_o, respectively (SHELX-76), and are characterized by triplets of facesharing octahedra parallel [00.1] with the cation-sequence M^III? Li? M^III, six of which are connected by [KF₆]-octahedra via common corners and each triplet is surrounded by six different [KF₆]-octahedra. The structure is completed by Cs⁺ filling the cavities. The Madelung Part of Lattice Energy (MAPLE), Mean Fictive Ionic Radii (MEFIR) and Effective Coordination Numbers (ECoN) are calculated and compared. The classification as lithometallate could be verified by a new MAPLE concept. The Charge Distribution (CHARDI) was calculated and compared with the results according to ‘bond length-bond strength’.     

Cyano‐Bridged MnIII?MIII Single‐Chain Magnets with MIII=CoIII,FeIII, MnIII,and CrIII

A series of isostructural cyano‐bridged Mn^III(h.s.)–M^III(l.s.) alternating chains, [Mn^III(5‐TMAMsalen)M^III(CN)₆] ? 4H₂O (5‐TMAMsalen^2?=N,N′‐ethylenebis(5‐trimethylammoniomethylsalicylideneiminate), Mn^III(h.s.)=high‐spin Mn^III, M^III(l.s.)=low‐spin Co^III, Mn? Co ; Fe^III, Mn? Fe ; Mn^III, Mn? Mn ; Cr^III, Mn? Cr ) was synthesized by assembling [Mn^III(5‐TMAMsalen)]³⁺ and [M^III(CN)₆]^3?. The chains present in the four compounds, which crystallize in the monoclinic space group C2/c, are composed of an [‐Mn^III‐NC‐M^III‐CN‐] repeating motif, for which the ‐NC‐M^III‐CN‐ motif is provided by the [M^III(CN)₆]^3? moiety adopting a trans bridging mode between [Mn^III(5‐TMAMsalen)]³⁺ cations. The Mn^III and M^III ions occupy special crystallographic positions: a C₂ axis and an inversion center, respectively, forming a highly symmetrical chain with only one kind of cyano bridge. The Jahn–Teller axis of the Mn^III(h.s.) ion is perpendicular to the N₂O₂ plane formed by the 5‐TMAMsalen tetradentate ligand. These Jahn–Teller axes are all perfectly aligned along the unique chain direction without a bending angle, although the chains are corrugated with an Mn‐N_axis‐C angle of about 144°. In the crystal structures, the chains are well separated with the nearest inter‐chain M???M distance being relatively large at 9 Å due to steric hindrance of the bulky trimethylammoniomethyl groups of the 5‐TMAMsalen ligand. The magnetic properties of these compounds have been thoroughly studied. Mn? Fe and Mn? Mn display intra‐chain ferromagnetic interactions, whereas Mn? Cr is characterized by an antiferromagnetic exchange that induces a ferrimagnetic spin arrangement along the chain. Detailed analyses of both static and dynamic magnetic properties have demonstrated without ambiguity the single‐chain magnet (SCM) behavior of these three systems, whereas Mn? Co is merely paramagnetic with S_Mn=2 and D/k_B=?5.3 K (D being a zero‐field splitting parameter). At low temperatures, the Mn? M compounds with M=Fe, Mn, and Cr display remarkably large M versus H hysteresis loops for applied magnetic fields along the easy magnetic direction that corresponds to the chain direction. The temperature dependence of the associated relaxation time for this series of compounds systematically exhibits a crossover between two Arrhenius laws corresponding to infinite‐chain and finite‐chain regimes for the SCM behavior. These isostructural hetero‐spin SCMs offer a unique series of alternating [‐Mn‐NC‐M‐CN‐] chains, enabling physicists to test theoretical SCM models between the Ising and Heisenberg limits.     

Synthesis,characterization and magnetic properties of cyanide bridged 1-D metal-coordination polymers based on [FeIII(s-bqdi)2(CN)2]−

A new series of transition metal complexes K[M^II(s-bqdi)₂][Fe^III(s-bqdi)₂(CN)₂]?·?10H₂O (s-bqdi?=?semibenzoquinonediiminate, M^II?=?Co (2), Ni (3), and Cu (4)) have been synthesized. These complexes have been characterized by elemental analyses, FT IR, Far IR, FAB mass, UV-Vis, TGA, CV measurements, and powder XRD. The powder XRD patterns of 2, 3, and 4 show that they are isostructural with hexagonal primitive lattice structures. The coordination polymers display 1-D chain networks. Magnetic properties of the Co^IIFe^III complex studied by a SQUID magnetometer reveal low-temperature antiferromagnetic interaction.     

Pressure versus Temperature Effects on Intramolecular Electron Transfer in Mixed‐Valence Complexes

Mixed‐valence trinuclear carboxylates, [M₃O(O₂CR)₆L₃] (M=metal, L=terminal ligand), have small differences in potential energy between the configurations M^IIM^IIIM^III?? M^IIIM^IIM^III??M^IIIM^IIIM^II, which means that small external changes can have large structural effects, owing to the differences in coordination geometry between M²⁺ and M³⁺ sites (e.g., about 0.2 Å for Fe? O bond lengths). It is well‐established that the electron transfer (ET) between the metal sites in these mixed‐valence molecules is strongly dependent on temperature and on the specific crystal environment; however, herein, for the first time, we examine the effect of pressure on the electron transfer. Based on single‐crystal X‐ray diffraction data that were measured at 15, 90, 100, 110, 130, 160, and 298 K on three different crystals, we first unexpectedly found that our batch of Fe₃O (O₂CC(CH₃)₃)₆(C₅H₅N)₃ ( 1 ) exhibited a different temperature dependence of the ET process than previous studies of compound 1 have shown. We observed a phase transition at around 130 K that was related to complete valence trapping and Hirshfeld surface analysis revealed that this phase transition was governed by a subtle competition between C? H???π and π???π intermolecular interactions. Subsequent high‐pressure single‐crystal X‐ray diffraction at pressures of 0.15, 0.35, 0.45, 0.74, and 0.96 GPa revealed that it was not possible to trigger the phase transition (i.e., valence trapping) by a reduction of the unit‐cell volume, owing to this external pressure. We conclude that modulation of the ET process requires anisotropic changes in the intermolecular interactions, which occur when various directional chemical bonds are affected differently by changes in temperature, but not by the application of pressure.     

Synthesis,structures, IR spectra,and thermal characteristics of compounds of general formula Ba(M<Stack><Subscript>2/3</Subscript><Superscript>III</Superscript></Stack>U<Subscript>1/3</Subscript>)O<Subscript>3</Subscript> (M<Superscript>III</Superscript> = Sc,Y, In,Nd-Lu)

Compounds with the composition Ba(M _2/3 ^III U_1/3)O₃ (M^III = Sc, Y, In, Nd-Lu) were synthesized by high-temperature solid-state reactions. The structures of the compounds were studied by X-ray diffraction analysis, including the high-temperature method, and IR spectroscopy.     

Neue Fluoride MIIIMIVF7 mit MIII = SE,Tl und MIV = Sn,Pb, Pt

New Fluorides M^IIIM^IVF₇ with M^III = SE, Tl and M^IV = Sn, Pb, Pt Colourless Fluorides MSnF₇ (M = La, Sm, Gd, Yb, Lu, Tl), TlPbF₇ and yellow compounds MPtF₇ (M = Eu, Y, Lu) were obtained for the first time either as single crystals or powder samples. They crystallize isostructural to SmZrF₇ (space group P2₁/c-C_2h⁵, Nr. 14; P2₁/n, Z = 4). Crystal data see “Inhaltsübersicht”.     

[CrIII8MII6]12+ Coordination Cubes (MII=Cu, Co)

[Cr^III₈M^II₆]¹²⁺ (M^II=Cu, Co) coordination cubes were constructed from a simple [Cr^IIIL₃] metalloligand and a “naked” M^II salt. The flexibility in the design proffers the potential to tune the physical properties, as all the constituent parts of the cage can be changed without structural alteration. Computational techniques (known in theoretical nuclear physics as statistical spectroscopy) in tandem with EPR spectroscopy are used to interpret the magnetic behavior.