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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.

(N2H5)3[GaF6] contains GaF63− octahedra arranged in a distorted cubic close-packed manner and linked to hydrazinium(1+) ions via N—H⋯F hydrogen bonds. (N2H6)[GaF5(H2O)] contains [GaF5(H2O)]2− octahedra arranged in a similar distorted cubic close packing manner; in addition to N—H⋯F hydrogen bonds to hydrazinium(2+) ions, these octahedra are also linked directly via O—H⋯F hydrogen bonds.

The compounds ethyl (E)-2-benzoyl-3-(dimethylamino)propenoate, C 14 H 17 NO 36 (I), ethyl (Z)-2-benzoyl-3-[(3nitrophenyl)amino]propenoate, C 18 H 16 N 2 O 5 (II), and methyl (Z)-3-[(4,6-dimethyl-2-pyrimidinyl)amino]-2[(methoxy)(methylthio)methyleneamino]propenoate, C 13 H 18 N 4 O 3 S (III), are propenoates with different substituents at the C(2) = C(3) double bond. C(2) bears benzoyl and ethoxycarbonyl groups in (I) and (II) and (methoxy)(methylthio)methyleneamino and methoxycarbonyl groups in (III), whereas C(3) is substituted with dimethylamino in (I), 3-nitrophenylamino in (II) and 4,6-dimethyl-2-pyrimidinylamino in (III). The configuration with respect to the C(2) = (3) double bond is E in (I) and Z in (II) and (III). Bulky substituents such as the benzoyl and (methoxy) (methylthio) methyleneamino groups are turned out of the best plane through the rest of molecule

The compound methyl (1'S,8S,10S)-6-chloro-9,10-dihydro-12,12-dimethyl-10-(D-erythritol-1-yl)-8H,12H-pyrazolo[1',2':1,2]pyrazolo[4,3-d]tetrazolo[1,5-b]pyridazine-8-carboxylate, C 16 H 22 ClN 7 O 6 , (1), is an example of a new C-nucleoside. Both (1) and dimethyl (6-chloro-9,10-dihydro-12,12-dimethyl-10-phthalimidomethyl-8H,12H-pyrazolo[1',2':1,2]pyrazolo[4,3-d]tetrazolo[1,5-b]pyridazine-8,9-dicarboxylate, C 23 H 21 ClN 8 O 6 , (II), contain heterocyclic systems consisting of four condensed fused rings. In each compound, the tetrazole ring is planar to within experimental error; the pyridazine ring and the pyrazole ring, which is fused to the pyridazine ring, deviate slightly from planarity, as does the phthalimido group of (II)

The molecular structures of three substituted 3-amino-2-benzoylaminopropenoic acid derivatives, methyl (Z)-2-benzoylamino-3-dimethylaminopropenoate (A), methyl (Z)-2-benzoylamino-3-(4,6-dimethyl-2-pyrimidinylamino)propenoate (B) and N-[(Z)-2-benzoylamino-3-(4,6-dimethyl-2-pyrimidinylamino)propenoyl]-L-proline monohydrate (C), show that the configuration around the exocyclic C=C double bond is Z. The mechanisms of syntheses of (B) and (C) from (A) are confirmed as the Z configuration is preserved in the title compounds

The Mo atoms in the title compounds, i.e. triethyl­ammonium cis-tetra­chloro­bis(4-ethyl­pyridine-N)­molybdate(III), cis-(C6H16N)­[MoCl4(C7H9N)2], and trans-tetra­chloro­bis(4-ethyl­pyridine-N)molybdenum(IV), trans-[MoCl4(C7H9N)2], are six-coordinate with octahedral geometry. The Mo atom in the latter complex lies on a site with crystallographic 2/m symmetry.

This paper discusses a transmission electron microscope investigation of a ZnO powder and low-temperature air-sintered pellets with small additions of Sb{sub 2}O{sub 3}. It was conducted in order to study the thin Sb-rich film on the surfaces of ZnO particles. This film was found to be noncrystalline at temperatures below 700 {degrees} C, and partially crystalline or completely crystalline above this temperature. An oriented overgrowth of the spinel Zn{sub 7}Sb{sub 2}O{sub 12} was observed on the prismatic planes as well as on the basal planes of ZnO crystallites. It is shown that these coherently overgrown spinel films are responsible for the inhibition of grain growth at high temperatures.

In the title compound, [Cu(C 2 H 3 O 2 ) 2 (C 6 H 8 N 2 ) 2 ], the Cu atom is surrounded by two O atoms from the two mono-dentate acetate ligands and by two pyridine N atoms from the two 2-amino-6-methylpyridine ligands in a trans square-planar arrangement. The Cu-O and Cu-N distances are 1.952(2) and 2.046 (2) A, respectively. The complex has an inversion centre. The remaining carboxylate O atoms are located at 2.764 (3) A from the Cu atom, above and below this plane. The coordination around the Cu atom can therefore be described as (4+2). The pyridine ring is twisted 73.2 (1)° with respect to the plane formed by the Cu, the N and the more strongly bonded O atoms.

The Cu II atom in [Cu(C 7 H 5 O 3 ) 2 (C 6 H 6 N 2 O)2(H 2 O)) 2 is octahedrally coordinated by N atoms from two nicotinamide ligands [at 2.018(2) and 2.019 (2) A], by O atoms of two salicylate ligands [at 1.9656(19) and 1.9762(19) A], and by trans water molecules at considerably different distances [2.373 (3) and 2.894 (4) A]. Neutral monomeric units are held together by hydrogen bonds through water molecules and N and O atoms of the CONH 2 group of nicotinamide and carboxylate groups.

The structure of octa-μ-methoxo-octa-μ-oxo-octa­oxotetra­pyridine­octa­molybdenum(V), [Mo8O16(CH3O)8(C5H5N)4], consists of discrete puckered cyclic molecules, made up of eight Mo atoms which are linked together by pairs of oxo bridges and pairs of bridging methoxy groups. It may also be regarded as a linkage of four [Mo2O4]2+ units, whose two Mo centres differ in their coordination by the pyridine ligand. Short Mo—Mo distances, 2.570 (1) A, alternate with longer Mo⋯Mo contacts, 3.435 (1) A.

By a selective exchange of ligand Br by Cl, a series of nonstoichiometric bromo-chloro-pyridine- molybdenum(III) octahedral compounds of the type (cat)[MoBraCl(4-a)py2] (cat = pyH, a = 3–1 (1, 4, 7)); cat = [(C2H5)3NH], a = 2.744 (2); cat = Rb, a = 2.278 (5); cat =[(C6H5)4)As], a = 1.258 (8) and [MoBraCl(3–a)py3] (a = 2–1 (3, 6)) have been prepared and characterized. Owing to great similarity of the powder diffraction patterns and IR spectra of compounds mer- [MoBraCl(3-a)py3] (a = 3–0) with the known monoclinic modification in the space group P21/c and compounds [MoBraCl(3-a)py3] (a = 2-1 (3, 6)), the same type of crystal lattice was confirmed. Isostructurality was observed also for the orthorhombic trans-(pyH)[MoBr4py2]](Pnma) and compounds 1 and 4, while compound 7 is isostructural to trans-(pyH)[MoCl4py2]. X-ray crystallographic analyses of 2, 5 and 8, obtained by recrystallization of (pyH)[MoBraCl(4-a)py2] (a = 3–1) with different cations, were performed. In these compounds, MoIII is octahedrally coordinated with four halogenido ions at distances 2.4953(6)–2.5920(10) Å and two pyridine molecules at distances 2.195(4)-2.220(4) Å. Trans oriented pyridine rings in compounds 5 and 8 are co-planar, while deviation from co-planarity was noticed for compound 2 (8.9(3)°). The stoichiometry of four coordinated Br and Cl atoms in these compounds is not ideal, since the structure analysis results for 2, 5 and 8 show a mixed occupancy of crystallographic sites; thus, refined population parameters for both atoms (Br and Cl) were calculated., Selektivnom zamjenom bromovoga liganda klorovim dobijena je i karakterizirana serija nestehiometrijskih bromo-kloro-piridin-MoIII kompleksa tipa (cat)[MoBraCl(4–a)py2] (cat = pyH, a = 3–1 (1, 4, 7); cat = [(C2H5)3NH], a = 2.744 (2); cat = Rb, a = 2.278 (5); cat = [(C6H5)4As], a = 1.258 (8)) i [MoBraCl(3–a)py3] (a = 2–1 (3, 6)). Uslijed velike sličnosti difraktograma praha i IR spektara spojeva mer-[MoBraCl(3–a)py3] (a = 3–0) poznate monoklinske modifikacije u prostornoj grupi P21/c i spojeva [MoBraCl(3–a)py3] (a = 2–1 (3, 6)), potvr|en je isti tip kristalne re{etke. Opa`ena je izostrukturnost rompskoga trans-(pyH)[MoBr4py2] (Pnma) i spojeva 1 i 4, dok je spoj 7 izostrukturiran s trans-(pyH)[MoCl4py2]. Načinjena je rentgenska strukturna analiza spojeva 2, 5 i 8 dobijenih prekristalizacijom (pyH)[MoBraCl(4–a)py2] (a = 3–1) s različitim kationima. U tim je spojevima MoIII oktaedarski koordiniran s četiri halogenidna iona na udaljenostima 2.4953(6)–2.5920(10) Å i dvije molekule piridina na udaljenostima 2.195(4)–2.220(4) Å. Trans orijentirani piridinski prstenovi u spojevima 5 i 8 su koplanarni dok je kod spoja 2 ustanovljena devijacija od koplanarnosti (8.9(3)°). Strukturnom analizom utočnjeni su faktori zauzetosti četiri koordinirana atoma (Br, Cl) u spojevima 2, 5 i 8. Na|eno je da su navedeni kristalografski položaji zauzeti atomima Cl i Br u nestehiometrijskome omjeru.

The structure of the title compound, Na2[Zn(C6H11O2)4], consists of two-dimensional polymeric sheets. The Zn2+ ions are approximately tetrahedrally coordinated by O atoms from different hexanoate anions. Both Na+ ions are six-coordinated by carboxyl­ate O atoms. One of the hexanoate O atoms is attached to one Zn2+ ion and one Na+ ion, and the remaining O atom is attached to two Na+ ions.

A novel anionic cobalt-substituted zincophosphate framework with a hexagonal unit cell of composition Na6[Co0.2Zn0.8PO4]6·9H2O is synthesised and its crystal structure determined by single crystal X-ray diffraction.

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.

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.

C 8 H 10 N 4 O 2 cristallise dans le systeme monoclinique avec le groupe d'espace P2 1 . Affinement de la structure jusqu'a 0,069

Ammonium hydrogen maleate, NH4+C4Ha04- crystallizes in the orthorhombic system with a = 0.4616(1), b = 0.8085(2), c = 1.6410(5) nm, Z = 4 in space group Pbcm, and is isostructural with the analogous potassium salt. The crystal structure has been refined from diffracton1eter data to conventional R and Rw of 0.052 and 0.065 for 690 reflexions [I> 3 a (I)]. Minor changes in the crystal struc-· ture were observed due to formation of N-H · · · 0 hydrogen bonds.