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The Li1.746Nd4.494FeO9.493 (LNF) ternary phase, located in the Li2O-rich part of the Li2O–Nd2O3–Fe2O3 system, crystallizes with a cubic unit cell of dimension a = 11.9763 ( 3 ) A and the space group Im 3 m . Refinement on F resulted in R = 1.9 % . The structure is comprised of a network of corners, edges and faces sharing the coordination polyhedra of neodymium. In between this skeleton the regular octahedra of oxygen-coordinated iron and trigonal prisms of lithium are located. The Mossbauer spectra revealed the presence of Fe3+, Fe4+ and Fe5+ ions distributed on two symmetry-independent lattice positions.

Di- O -isopropylidene- and O -methanesulfonyl-protected 1- C -(6-chloro-1,2,4-triazolo[4,3- b ]pyridazin-3-yl)pentitols were prepared in three to four steps from d -galactose, d -glucose, d -mannose, and 2,3:5,6-di- O -isopropylidene-α- d -mannofuranose. Acid-catalysed treatment of (1 S )- and (1 R )-1- C -(6-chloro-1,2,4-triazolo[4,3- b ]-pyridazin-3-yl)-2,3:4,5-di- O -isopropylidene-1- O -methanesulfonyl- d -arabinitols in refluxing 1,2-dimethoxyethane furnished 3-(α- and β- d -arabinofuranosyl)-6-chloro-1,2,4-triazolo[4,3- b ]pyridazine, respectively. Several structures, including the structure of the 3-(β- d -arabinofuranosyl)-6-chloro-1,2,4-triazolo[4,3- b ]pyridazine, were also determined by single-crystal X-ray diffraction analysis.

Some new aplysinopsin analogues were prepared by a simple coupling of N , N -(dimethylamino)methylidene substituted hydantoin, thiohydantoin, and thiazolone derivatives, with indole derivatives. Configuration around the exocyclic CC double bond was determined on the basis of long-range heteronuclear coupling constants using 2D HMBC correlation technique.

(PyH)2[MoOCl5] reacts with methanol and pyridine or 4-methylpyridine to give neutral oxomolybdenum(V) and oxomolybdenum(V,VI) clusters built of Mo2O4 2+ units, i.e. tetranuclear [Mo4O8(OCH3)2Cl2Py4]·2Py (Py=pyridine (C5H5N)) (i), [Mo4O8(OCH3)2Cl2(4-MePy)4]·2(4-MePy) (4-MePy=4-methylpyridine (C6H7N)) (ii), [Mo4O8(OCH3)4(4-MePy)4] (iii), hexanuclear [Mo6O12(OCH3)6Py4] (iv) and decanuclear [Mo10O26Py8]·7Py (v). It was shown by the X-ray structure analysis that i and iii contain the same [Mo4O4(μ2-O)2(μ3-O)2(μ2-OCH3)2]2+ core to which different peripheral ligands are attached. The structure of ii is analogous to that of i, based on the similarity of infrared and far infrared spectra. Molecules of iv were shown to contain a planar arrangement of six molybdenum atoms linked together by oxo and methoxo bridging groups. The X-ray structure analysis of v revealed the presence of molybdenum(V) and molybdenum(VI) atoms. Neutral, decanuclear molecules of v are built of four Mo2O4 2+ units which are connected with two molybdenum(VI) centres.

Reactions of (PyH)2[MoOCl5] with methanol and 3,5-lutidine or 3-methylpyridine carried out under conditions of solvothermal synthesis at 130°C have resulted in two Mo(V, VI) clusters containing the same molybdenum oxide framework, [Mo10O26(3,5-Lut)8]·2(3,5-Lut) (3,5-Lut=3,5-lutidine (C7H9N)) (i) and [Mo10O26(3-MePy)8]·(3-MePy) (3-MePy=3-methylpyridine (C6H7N)) (ii), and in a novel [Mo12O28(OCH3)2Cl2(3-MePy)8] (iv). [Mo10O26(3-MePy)8] (iii) was also obtained by oxidizing (NH4)2[MoCl5(H2O)] in a mixture of methanol, 3-methylpyridine and nitromethane. X-ray structural analyses revealed Mo2O4 2+ unit as a common structural motif in both cluster types. In i–iii ten molybdenum atoms are grouped into four Mo2 V pairs with MoMo bonds and two Mo(VI) sites. The oxomolybdenum core of iv is composed of six Mo2 V pairs connected through oxo and methoxo bridges.

Simple synthetic routes for the preparation of octanuclear oxomolybdenum(V) clusters with stoichiometry [Mo8O16(OCH3)8L4] (L=4-methylpyridine (4-MePy) (a), 4-ethylpyridine (4-EtPy) (b), 4-tert-butylpyridine (4-ButPy) (c), pyridine (Py) (d), 3-methylpyridine (3-MePy) (e), 3,5-lutidine (3,5-Lut) (f)) are described. Crystal structures of e and f were investigated by X-ray diffraction. The puckered ring structure made up of eight molybdenum atoms linked together by pairs of methoxy groups and pairs of oxo groups was recognized in both. The solubility of the compounds in pyridines was employed for the substitution of coordinated pyridine for a different pyridine. The octanuclear clusters have been found to react in pyridines at elevated temperatures to oxomolybdenum(V,VI) clusters with the formula [Mo10O26L8].

Complexes of [LnCl3L] (Ln=La, Nd, Sm, Eu, and L=diethylene glycol dimethyl ether, diglyme; Ln=La, Pr, and L=dimethoxyethane, DME) were prepared from the lanthanide oxides and hydrogen chloride, which was formed in situ from chlorotrimethylsilane and water. When hexamethylphosphoramide (HMPA) was added to the suspension of the prepared DME and diglyme complexes in toluene, fac-[LnCl3(HMPA)3] (Ln=La, Pr, Nd, Sm, Eu, Gd) complexes, isomorphous according to the unit cell determination, were formed. The crystal structure of [SmCl3(HMPA)3] was determined. Each samarium atom is octahedrally coordinated by three chlorine atoms and three HMPA molecules, which are distributed in a facial mode. The exchange of coordinated and free HMPA, as well as the reversible fac–mer isomerization of [LaCl3(HMPA)3], was observed by variable temperature 1H NMR spectroscopy. The associative mechanism of the exchange and isomerization was proposed.

Complexes of [LnCl3(dme)2] (Ln=Sm, Gd; dme=dimethoxyethane)were prepared in dimethoxyethane solution from the lanthanide oxides and hydrogen chloride, which was formed in situ from chlorotrimethylsilane and water. The recrystallization of[LnCl3(dme)2] from tetrahydrofuran in the presence of tetramethylethylenediamine (tmeda) resulted in [LnCl3(thf)2(tmeda)] (Ln=Sm,Gd). The samarium and gadolinium complexes were found to be isomorphous by unit cell determination. Each seven-coordinated gadolinium atom adopts a distorted pentagonal bipyramidal geometry with chlorine atoms in axial positions. The thermal decomposition of the compounds in argon resulted in LnOCl.

Cobalt-containing aluminophosphate AlPO 4 -CJ2 was hydrothermally synthesized and characterized using single crystal X-ray diffraction. It was shown to possess 7.2(3) % of isomorphously substituted cobalt in a 5-coordinate Al framework site and a 4-coordinated extra-framework Co (II) ion in a distorted square-planar arrangement with one terminal fluoride atom and three framework oxygen atoms (7.2(3)% occupancy). The Co incorporation does not change the cell parameters significantly ( a = 9.444(1), b = 9.588(1), c = 9.928(1)A). The orthorhombic P2 1 2 1 2 1 symmetry found for the Co-free analogue is also retained.

We report on the synthesis and single-crystal structure of a novel cobalt-substituted aluminophosphate. Crystal data: monoclinic, space group P2 1 c (no. 14), a = 8.593(1), b = 15.540(1), c = 7.736(1)A, β = 110.65(1)°, V = 966.7(4)A3, Z = 4, R = 0.037, and Rw = 0.029 for 2280 contributing reflections and 182 variables. Refined framework-atom bond distances and angles exhibited regular tetrahedral coordination of Al and P [dave(AlO) = 1.74(1)A, dave(PO) = 1.54(2)A] and distorted Co-centered octahedra. The Co substituted every second aluminum in the ordered AlP distribution and was coordinated to five framework oxygen atoms and to one nitrogen atom from a template ethylenediamine molecule located in an eight-member ring opening. Structure collapsed in the absence of template.

A single-crystal EPR study of tetraphenylarsoniumtetrachloro nitrido-technetate (VI), (Ph 4 As) [Tc 15 NCl 4 ], diamagnetically diluted by the isoelectronic oxotechnetate (V) complex, and the crystal structure of the host complex are reported. (Ph 4 As) [TcOCl 4 ] crystallizes tetragonal, space group P4/n, Z =2 with a = b = 12.670(1) and c =7.824(1) A. The anion possesses C 4v symmetry. The EPR spectra are typical of an ion with a 4d 1 configuration. At low temperatures very complex 35,37 Cl and 15 N ligand hyperfine patterns are observed. The 99 Tc, 35,37 Cl and 15 N hyperfine data are analyzed to evaluate the electron spin delocalization: 20% of the spin density is localized in mainly the 3p orbitals of the Cl atoms.

(Ph 4 As) 2 [TcN(dto) 2 ] can be prepared starting from TcNCl 4 − or TcNCl 2 (Ph 3 P) 2 . The compound crystallizes in at least two modifications: as well as a triclinic form (S. F. Colmanet and M. F. Mackay, Inorg. Chim. Acta, 147 (1988) 173) a monoclinic one has been found (space group C 2/ c , Z = 4, a = 19.424(3), b = 11.254(2), c = 24.958(3) A, β = 107.68(1)°; R = 0.048). Distances and angles in the complex anions in both modifications are almost identical within experimental error. Oxidation of [TcN(dto) 2 ] 2− by Cl 2 produces the Tc(VI) complex TcNCl 4 − exclusively, whereas during the Br 2 oxidation technetium(VI) intermediates are generated containing mixed Br/dto coordination spheres which can be monitored easily by EPR spectroscopy.

In a regiospecific 1,3-dipolar cycloaddition of 2- diazopropane to 2-itiethyl-6-phenylpyridazin-3(2H)- one the primary cycloadduct and rearranged NH,NH- dihydro cycloadduct were isolated. They were transformed, dependent on the reaction conditions into 1,2-di- azepine derivative, 4-isopropyl substituted pyridazine derivative, diazabicyclo/4.l.0/heptenone derivative and pyrazolo/3,4-d/pyridazine derivative. 1,5- Sigmatropic rearrangements were observed, when was heated in PPA or concentrated sulphuric acid to give pyrazolo/3,4-d/pyridazine derivatives 0 and 1 , and a pyrazole derivative 3 .

The “quasi” ternary system Sr2EuFeO5-SrO-PbO was investigated and the compounds Sr2ReAlO5 (Re = La, Pr, Nd, Sm, Eu, Ga, Tb) and Sr2ReFeO5 (Re = Nd, Sm, Eu, Gd) were prepared in the form of monocrystals using the flux method.

The crystal and molecular structures of methyl 2,4,6-tri- O -pivaloyl-α- d -glucopyranoside ( 1 ), methyl 4,6- O -( R )-benzylidene-2- O -pivaloyl-α- d -glucopyranoside ( 2 ), and methyl 4,6- O -( R )-benzylidene-2,3-di- O -pivaloyl-α- d -glucopyranoside ( 3 ) were determined by X-ray analysis. Crystals of 1 are orthorhombic, space group P 2 1 2 1 2 1 with the unit cell a = 13.026(2), b = 16.832, c = 11.929(2) A, Z = 4. Crystals of 2 are monoclinic, space group P 2 1 . The unit-cell parameters are a = 6.519(1), b = 14.664(4), c = 10.635(4) A, β = 93.18(1)°, Z = 2. Crystals of 3 are orthorhombic, space group P 2 1 2 1 2 1 with a = 10.006(3), b = 13.874(3), c = 18.527(5) A, Z = 4. The structures were solved by MULTAN and refined by a full-matrix procedure to final values of R = 0.084 ( 1 ), 0.048 ( 2 ), and 0.069 ( 3 ). The pyranose ring in each compound adopts the 4 C 1 conformation. The 1,3-dioxane rings in 2 and 3 show a chair conformation. The molecular packing in 1 is through the hydrogen bonds involving HO-3 and the 6- O -pivaloyl carbonyl group [HO-3 ⋯ O-9, 2.855(8) A], which connect the molecules into a chain along . The endocyclic oxygen atom is involved in an intermolecular hydrogen-bond with HO-3 [2.848(4) A], joining molecules of 2 into the chains along . There are no free hydroxyl groups in 3 and molecular packing reflects van der Waals interactions only.

Carbon dioxide reacts with acetaldehyde in the presence of dipyNi(COD) (COD = 1,5-Cyclooctadiene) to yield a red organonickel(II) compound as the result of oxidative coupling of both hetero-π-systems at the central metal. The crystal and molecular structures have been determined by X-ray analysis. The complex is monoclinic (space group P21/n; cell data: a 6.004(2), b 18.012(7), c 11.266(5) », β 96.02(4)°, R = 0.10) with 4 molecules in the unit cell. The structure was solved by the heavy atom technique. The complex has a planar configuration at the central atom and contains a five-membered metallacycle with a metal—C and a metal—O σ-bond. Many other aliphatic aldehydes react with carbon dioxide to yield the same type of complex.

The crystal and molecular structures of methyl β- d -glucofuranosidurono-6,3-lactone (1), 5-O-pivaloyl-β- d -glucofuranurono-6,3-lactone (2), and methyl 2-O-acetyl-5-O-pivaloyl-β- d -glucofuranosidurono-6,3-l (3) were determined by X-ray analysis. Crystals of compound 1 are orthorhombic, space group P212121 with the unit cell a = 7.074(1), b = 7.448(1), c = 14.995(2) A, Z = 4. Crystals of 2 and 3 are monoclinic, space group P21. The unit-cell parameters are a = 6.315(1), b = 9.307(2), c = 10.612(2) A, β = 98.68(1)°, Z = 2 for 2; and a = 13.337(1), b = 10.296(1), c = 13.544(1) A, β = 118.24(1)°, Z = 4 for 3. The structures were solved by MULTAN-80 and refined by a full-matrix procedure to final values of R = 0.042(1), 0.048(2), and 0.093(3). The furanoid rings in 1, 2, and conformer B of 3 appear in twisted. 1T2 conformation, and the lactone rings adopt conformations between T and E. The lactone ring of conformer A of 3 adopts a T conformation and that of the furanoid ring is E2. The molecular packing is through the hydrogen bonds involving hydroxyl groups HO-2 · ⋯ O-1 [2.812(2) A] in 1. A hydrogen bond between a hydroxyl group and the pivaloyl carbonyl group, HO-1 · ⋯ O-7 [2.855(3) A], connects the molecules of 2. There are no free hydroxyl groups in 3 and molecular packing reflects van der Waals interactions only.

The relative configuration of the carbons bearing the ester groups in the cycloadducts of anhydro - 4- hydroxythiazolium hydroxides with dimethyl maleate and dimethylfumarate is revised in the light of an X-ray crystallographic analysis. Steric effects are considered to account for the preferred exo approach of the dipole and the dipoiarophile.

Synthesis and characterization of the first trischelates of the dichalcogenolene ligands 1,3-dithiole-2-thione-4,5-dithiolate (dmit), 1,2-dithiole-3-thione-4,5-dithiolate (dmt)and 1,3-diselenole-2-selone-4,5-diselenolate (dsis) with the central ions In(III), Tl(III) and V(IV) are reported. On (Bu4N)2[V(dmt)3] the first X-ray structure of a dithiolene tris-chelate containing unsymmetric ligand was carried out: the compound crystallizes monoclinic, space group P21/c, with four molecules in the unit cell; a = 16.264(3), b = 17.319(4), c = 21.554(4) A, β = 103.03(2)°. The ligand dmt causes a very low symmetry of the VS6 moiety in [V(dmt)3]2− having pseudo-meridional arrangement of the three ligands. The EPR parameters of the compounds (Bu4N)2[V(dmit)3] and (Bu4N)2[V(dmt)3] measured in liquid and frozen acetonic solution are compared with those of the tris(maleonitriledithiolato)vanadate(IV) anion supporting a geometry of the anion being between octahedral and trigonal prismatic.

The complete 103Rh and 33S hyperfine coupling tensors of the 4d7 low-spin chelate tetraphenylarsoniumbis (maleonitriledithiolato)rhodate(II) doped into the corresponding nickel complex salt have been measured by EPR-ENDOR spectroscopy. Both interactions are small and confirm that the unpaired electron is in an “out-of-plane” π-type molecular orbital. The Rh-S bonds are less covalent than bonds in the isoelectronic Pd(III) complex.

(morphH)2Mo2Cl6(H2O)2 (A) and (morphH)2Mo(2Br6(H2O)2 (B) (morph = C4H9NO) crystallize in the P1 space group with Z = 1 and comparable cell dimensions. Average MoMo distance is 2.12(1) A. Mo2 pairs have two different orientations with respect to the position of the remaining atoms forming Mo2X6(H2O)2−2 anion. Population factors for the disordered part are 14 and 33% for chloride and bromide. MoCl and MoBr bond lengths average 2.43(1) and 2.57(1) A. MoO(H2O) distances are 2.20(1) A and 2.23(1) A (B). Mo2X6(H2O)2−2 is located at the symmetry center. Morpholinium cations are in the chair conformation. Cations and anions are connected by electrostatic interactions and weak hydrogen bonds. (morphH)4Mo2Cl8 and the compound with the chemical composition of (morphH)2Mo2Br4.2Cl1.8(H2O)2 were prepared. All compounds were characterized by chemical and physical methods.

Phase equilibria in the binary system CaTiO 3 -SrTiO 3 were studied above 1300°C. This system is characterized by a complete series of solid solutions, with a minimum in the solidus at 23 mol% SrTiO 3 and 1940°C. The volume change of the unit cell of CaTiO 3 as a function of composition shows very little deviation from Vegard's law for solid solutions. No immiscibility gap was found.

A single-crystal ESR study of the mixed-ligand complex tetra - n - butylammonium - (maleonitriledithiolato)(diethyl - di - selenocarbamato)cuprate(II) diamagnetically diluted by the corresponding Ni(II) complex, and the crystal and molecular structure of the host complex determined by a single-crystal X-ray diffraction study, is reported. (n-Bu4N)[Ni(mnt)(et2dsc)] is monoclinic, space group C2/c, with eight molecules in the unit cell; a = 19.932(9) A, b = 9.597(3) A, c = 37.580(13) A and β = 101.32(3)°. Based on the structure the spin Hamiltonian parameters have been calculated from the results of extended Huckel molecular orbital calculations and compared with the experimentally obtained values. The principal axes of the g and the metal hyperfine tensor do not coincide reflecting the large influence of the et2dsc− ligand for which this behaviour was found to be typical. A comparison between the ESR parameters and the Mulliken spin densities of the mixed-ligand chelate and the corresponding parent complexes shows that in the former one spin density appears to be transfered from the S atoms to the Se atoms of the et2dsc− part of the complex resulting in an increased CuSe covalency. Back-bonding effects were considered in discussing the bonding properties.

Changes induced during the heating of hydrated NiTeO 3 in air and vacuum were investigated by means of DTA, TGA, chemical, X-ray and microprobe analysis. It was found that amorphous NiTeO 3 decomposes at 580–600°C to Ni 2 Te 3 O 8 . Monocrystals of Ni 2 Te 3 O 8 were isolated and found to be isomorphous with Zn 2 Te 3 O 8 . On heating in air, Ni 2 Te 3 O 8 oxidizes to Ni 3 TeO 6 and finally decomposes to NiO + TeO 2 .

Phase equilibria in the systems USCaS, USSrS and USBaS have been investigated by X-ray diffraction, metallography and electron-probe microanalysis. New ternary sulphides, CaUS2, SrUS2 and BaUS2, which appeared in the corresponding systems, formed eutectic mixtures with primary solid solutions. Eutectic melting temperatures were determined for the systems USCaS and USSrS and tentative phase diagrams constructed. Detailed crystal structure analyses of CaUS2 and SrUS2 were carried out.

The X-ray structure of (Ph3P)2Ag(SOC2SO)Ag(PPh3)2 shows this complex as the second authentic example containing a bridging trans-1,2-dithiooxalate ligand. The compound crystallizes in the monoclinic space group P21/c with a=13.159(2), b=11.895(2), c=20.939(5)A, β= 101.35(2)° and Z = 2. The structure was solved by Patterson and Fourier methods for 5649 diffractometer data and refined to a final R value of 0.066 for 03545 observed reflections. The dimensions of the dithiooxalate bridge are compared with those of the corresponding trans-dithiooxalate in (Ph4As)4 (O2C2S2)2In(SOC2SO)In(S2C2O2)2]. Differences between structures containing bridging trans-dithiooxalate or bridging cis-dithiooxalate, respectively, are discussed.

Single crystals of SrEu 2 Fe 2 O 7 have been grown from a PbO flux. Cell dimensions and a structure model of the tetragonal crystals have been deviced.

Single crystals of Eu 2 O 3 have been grown from a PbO flux. Cell dimensions of the monoclinic crystals has been deviced.