Ternary metal borides [La,Ce,Pr,Nd,Sm] Os4B4 and [Y,La,Ce,Pr,Nd,Sm,Gd,Tb] Ir4B4 with NdCo4B4-type structure

New ternary metal borides with compositionR. E. T ₄B₄ (R. E.=rare earth metal,T=transition metal) have been synthesized within the systems [La,Ce,Pr,Nd,Sm]–Os–B and [Y, La, Ce, Pr, Nd, Sm, Gd, Tb]–Ir–B. All compounds were found to be crystallizing with NdCo₄B₄-type structure. Magnetic measurements (80–300 K,Curie-Weiss behaviour, _p ~ 16K and µ_eff=9.94µ_B for TbIr₄B₄) indicate Y andR. E. elements (except Ce) to be trivalent in these compounds. The crystal chemistry of the isotypic series [Y,R. E.] [Os,Ir]₄B₄ is discussed.

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Ternäre Metallboride. [La,Ce,Pr,Nd,Sm] Os₄B₄ und [Y,La,Ce,Pr,Nd,Sm,Gd,Tb] Ir₄B₄ mit NdCo₄B₄-Struktur

Zusammenfassung Es wurden neue Metallboride der ZusammensetzungR. E. T ₄B₄ (R. E.=Seltenerdmetall,T=Übergangsmetall) innerhalb der Systeme [La,Ce, Pr,Nd,Sm]–Os–B und [Y,La,Ce,Pr,Nd,Sm,Gd,Tb]–Ir–B hergestellt. Alle Verbindungen kristallisieren entsprechend dem NdCo₄B₄-Typ. Magnetische Messungen (80–300K,Curie-Weiss-Verhalten, _p ~ 16K und µ_eff=9.94µ_B für TbIr₄B₄) zeigen an daß Y und dieR. E.-Elemente (ausgenommen Ce) in diesen Verbindungen trivalent sind. Die Kristallchemie der isotypen [Y,R. E.][Os,Ir]₄B₄-Verbindungen wird diskutiert.

     

The crystal structure of 1-(4-chlorophenyl)-3-(4-methylbenzoyl)thiourea

1-(4-Chlorophenyl)-3-(4-methylbenzoyl)thiourea was synthesized and characterized by IR,¹H and ¹³C NMR, mass spectroscopy and the elemental analysis. The crystal structure was confirmed from single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a=12.038(3), b=6.330(6), c=18.912(5) Å and β=100.32(3)°. There is a strong intramolecular hydrogen bond of the type N?H...O, with distance N1...O1=2.659(3) Å. The structure is composed of dimers related by inversion centers. The dimers are formed by intermolecular interactions of the type N?H...S with N...S separation of 3.440(2) Å. The mass fragmentation pattern has also been discussed.     

Synthesis and crystal structure of 1-ethyl-3-(phenyl)-1,2,3-triazolium percholorate

The isolation of stable carbenes of the Arduengo (1a) and Wanzlick (2a) type has prompted us to look for stable nitrenium ions of the related structural type 1-ethyl-3-(phenyl)-1,2,3-triazolium perchlorate (6⁺). The title compound C₁₀H₁₄Cl N₃O₄ was isolated and structure was investigated by X-ray crystallography. It crystallizes in the monoclinic space group P2₁/c with cell parameters a=6.697(4) Å, b=9.724(9) Å, c=19.844(2) Å and Z=4. The final residual factor is R1=0.0471 for 1545 reflections with I>2σ(I). The structure exhibits intermolecular hydrogen bonds.     

The crystal structure of ZnFe 2 3+ (SeO3)4

Summary The new synthetic compound ZnFe ₂ ³⁺ (SeO₃)₄ forms at low-hydrothermal conditions at 220 °C. It belongs to the monoclinic system; the structure was determined by single-crystal X-ray diffraction in the space group Pc. The unit cell data are:a=8.196(4) Å,b=7.997(4) Å,c=8.033(4) Å, =92.27(3)°,V=526.1 ų;Z=2. The structure of ZnFe ₂ ³⁺ (SeO₃)₄ contains two types of FeO₆ octahedra, one distorted ZnO₅ trigonal bipyramid, and four selenite groups. Formal clusters consisting of the ZnO₅ group, edge-linked with both FeO₆ groups and one SeO₃ pyramid, are connected by common corners, involving three further selenite groups to a framework structure.

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Die Kristallstruktur von ZnFe ₂ ³⁺ (SeO₃)₄

Zusammenfassung Die neue synthetische Verbindung ZnFe ₂ ³⁺ (SeO₃)₄ bildet sich bei niedrighydrothermalen Bedingungen (220°C). Die Kristallstruktur wurde mit Einkristallröntgenmethoden in der monoklinen Raumgruppe Pc gelöst. Die Zellparameter sind:a=8.196(4) Å,b=7.997(4) Å,c=8.033(4) Å, =92.27(3)°,V=526.1 ų;Z=2. Die Kristallstruktur von ZnFe ₂ ³⁺ (SeO₃)₄ weist zwei Arten von FeO₆-Oktaedern, eine verzerrte trigonale ZnO₅-Dipyramide sowie vier Selenitgruppen auf. Formal können Cluster, bestehend aus dem ZnO₅-Polyeder, kantenverknüpft mit den beiden FeO₆-Gruppen sowie einer SeO₃-Pyramide, beschrieben werden. Die Verknüpfung über Ecken zu einer Gerüststruktur erfolgt unter Beteiligung von drei weiteren Selenitgruppen.

     

Correlation of colour and crystal structure for silver(I) compounds

A geometrical analysis on 22 crystal structures of Ag(I) compounds with hard bases demonstrates that the observed colour-changes from colourless to red depend on the number of Ag(I) atoms coordinating the donor atoms of the base.

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Korrelation zwischen Farbe und Kristallstruktur in Silber(I)-VerbindungenKurze Mitteilung

Zusammenfassung Eine geometrische Analyse an 22 Kristallstrukturen von Ag(I)-Verbindungen mit harten Basen zeigt, daß sich die Farbe der Verbindungen mit steigender Anzahl von Silberatomen um die Donorzentren vertieft.

     

Synthesis and crystal structure of monoclinic Fe2(SeO4)3

Summary Crystals of monoclinic Fe₂(SeO₄)₃ were synthesized under hydrothermal conditions. The structure was determined by single crystal X-ray methods and refined in space group P2₁/n with 2 646 independent reflections (sin /<0.7 Å^–1) toR=0.033,R _w=0.037:a=8.530 (2) Å,b=8.888 (2) Å,c=11.952 (2) Å, =91.13 (1)°,V=906.0 ų,Z=4. The crystal structure is isotypic with the monoclinic modification of Fe₂(SO₄)₃, containing two different Fe(III) and three Se(VI) atomic positions. The FeO₆ and SeO₄ polyhedra are only slightly distorted, the mean Fe-O bond lengths are 1.986 Å and 2.004 Å, the average distances within the SeO₄ tetrahedra are each 1.628 Å. The isolated FeO₆ octahedra only share corners with SeO₄ tetrahedra to build a framework structure.

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Synthese und Kristallstruktur von monoklinem Fe₂(SeO₄)₃

Zusammenfassung Kristalle von monoklinem Fe₂(SeO₄)₃ wurden unter Hydrothermalbedingungen gezüchtet. Die Struktur wurde mit Einkristall-Röntgenmethoden bestimmt und in der Raumgruppe P2₁/n mit 2 646 unabhängigen Reflexen (sin /<0.7Å^–1) aufR=0.033,R _w=0.037 verfeinert:a=8.530(2) Å,b=8.888(2) Å,c=11.952(2) Å, =91.13(1)°,V=906.0 ų,Z=4. Die Kristallstruktur ist isotyp mit der monoklinen Modifikation von Fe₂(SO₄)₃, sie enthält zwei unterschiedliche Fe(III) und drei Se(VI) Atompositionen. Die FeO₆-Polyeder sind nur gering verzerrt, die mittleren Fe-O Bindungslängen sind 1.986 Å und 2.004 Å, die mittleren Abstände in den SeO₄-Tetraedern sind jeweils 1.628 Å. Die isolierten FeO₆-Oktaeder sind nur über gemeinsame Ecken mit SeO₄-Tetraedern verbunden, wobei eine Gerüststruktur entsteht.

     

Röntgenstrukturanalyse des Methyl-5-acetylamino-7,8-anhydro-4,9-bis-O-(t-butyldimethylsilyl)-3,5-didesoxy-L-glycero-β-D-galakto-2-nonulopyranosidon-säuremethylesters

An X-ray crystal structure analysis of the title compound was carried out at –168°C in order to assign the stereochemistry around the oxirane: C₂₅H₄₉NO₈Si₂, trigonal, R3,a=25.18(1),c=13.55(1) Å (hexagonal axes),Z=9,d _x =1.105.The structure was solved with direct methods and refined to anR-factor of 0.086.

     

Bonding in phenylhydrazones: X-ray crystal structure and theoretical calculations involving (E)-acetophenone phenylhydrazone

Summary Semiempirical (PM3 type) calculations have been carried out on theE isomer of acetophenone phenylhydrazone and extended to include acetophenoneimine and phenylhydrazone. The optimized structure of acetophenone phenylhydrazone has also been compared with the solid state structure obtained from the results of an X-ray crystal structure determination. The crystals are monoclinic, space group P2₁/c,a=5.520(2) Å,b=8.944(3) Å,c=23.591(8) Å, =90.28(3)°, andV=1164.7(7) ų. The finalR value is 0.0549 for 1097 reflections withF>3(F). The structure possesses a planar conformation and both N atoms possess trigonal-planar geometries. Results of the theoretical calculation are in good agreement with those obtained from the crystallographic data and indicate that conjugation between the hydrazone region and the phenyl rings plays a significant role in favoring a planar molecular conformation and has a significant perturbing influence on the bond lengths and angles associated with the hydrazone C=N-N atoms. A Mulliken analysis for the structure gives bond orders of 1.77 and 1.10 for the formally double bonded C-N and single-bonded N-N atoms, respectively.

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Bindungen in Phenylhydrazonen. Röntgenstrukturanalyse und theoretische Berechnungen an (E)-Acetoxyphenon-phenylhydrazin

Zusammenfassung Es wurden semiempirische PM3-Typ-Berechnungen für dasE-Isomere von Acetophenon-phenylhydrazon durchgeführt und dann auf Acetophenonimin und Phenylhydrazon ausgeweitet. Die optimierte Geometrie von Acetophenon-phenylhydrazon wurde mit der Kristallstruktur dieser Verbindung verglichen. Die Kristalle sind monoklin, Raumgruppe P2₁/c,a=5.520(2) Å,b=8.944(3) Å,c=23.591(8) Å, =90.28(3)° undV=1164.7(7) ų. Der endgültigeR-Wert für 1097 Reflexe mitF>3(F) war 0.0549. Die Struktur besitzt eine planare Konformation und beide N-Atome haben trigonal-planare Geometrien. Die Ergebnisse der theoretische Berechnungen sind in guter Übereinstimmung mit jenen aus den kristallographischen Daten und zeigen, daß die Konjugation zwischen dem Hydrazonteil und den Phenylringen eine signifikante Rolle bei der planaren Konformation trägt und auch einen entscheidenden Einfluß auf Störungen bei Bindungslängen und-winkel in der Hydrazongruppierung C=N-N hat. Eine Mulliken-Analyse der Struktur ergab Bindungsordnungen von 1.77 bzw. 1.10 für die formale Doppelbindung C-N bzw. die Einfachbindung N-N.

     

Ternäre Lithium-Selten-Erd-Nitrate mit einsamen Nitrationen: Li3[M(NO3)5](NO3) (M = Gd?Lu,Y). Die Kristallstruktur von Li3Er(NO3)6

Ternary Lithium Rare Earth Nitrates with Lonesome Nitrate Ions: Li₃[M(NO₃)₅](NO₃) (M = Gd? Lu, Y). The Crystal Structure of Li₃Er(NO₃)₆ Single crystals of the ternary nitrate Li₃Er(NO₃)₆ are obtained from a solution of “Er(NO₃)₃” in the melt of LiNO₃. In Li₃Er(NO₃)₆ (monoclinic, P2₁/n, Z = 4; a = 776.0(1); b = 748.86(8); c = 2 396(1) pm; β = 90.76(3)°; R1 = 0.0490; wR2 = 0.0792), Er³⁺ is surrounded by five bidentate nitrate ligands yielding the anionic units [Er(NO₃)₅]^2?. These are arranged in the direction of the 2₁ screw axis. Two lonesome NO₃^? ions are in the middle of such a “helix” and are connected by Li⁺ with the anions [Er(NO₃)₅]^2?. The helices are moved against each other by about half of the lattice constant a and are connected by further Li⁺ ions.     

The crystal structure of the new ternary antimonide Dy3Cu20+xSb11−x (x≈2)

New ternary antimonide Dy₃Cu_20+xSb_11−x (x≈2) was synthesized and its crystal structure was determined by direct methods from X-ray powder diffraction data (diffractometer DRON-3M, CuKα-radiation, R_I=6.99%,R_p=12.27%,R_wp=11.55%). The compound crystallizes with the own cubic structure type: space group , Pearson code cF272, . The structure of the Dy₃Cu₂₀Sb_11−x (x≈2) can be obtained from the structure type BaHg₁₁ by doubling of the lattice parameter and subtraction of 16 atoms. The studied structure was compared with the structures of known compounds, which crystallize in the same space group with similar cell parameters.     

The preparation,properties and gas-phase molecular structure of difluoro(germylthio)phosphine

Difluoro(germylthio)phosphine, PF₂(SGeH₃), has been prepared by the reaction of S(PF₂)₂ with GeH₃Cl, and has been characterised by i.r.,Raman, n.m.r. and mass spectroscopy. Cleavage reactions with Cl₂ and HBr, donor reactions of the phosphorus atom and exchange reactions with platinum complexes have been studied. The molecular structure of PF₂(SGeH₃) in the gas phase has been determined by electron diffraction. Principal parameters (r _a) are:r(Ge–S) 225.6(4)pm;r(P–S) 211.5(8)pm;r(P–F) 159.0(9)pm; <(GeSP) 99.0(6)° <(SPF) 99.9(4)° <(FPF) 97.0(10)°. The conformation adopted is such that there are short non-bonded F...H contacts, with the PF₂ group twisted 18° from the position in which the FPF angle bisector eclipses the Ge–S bond.

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Difluor(germylthio)phosphin. Darstellung, Eigenschaften und Molekülstruktur in der Gasphase

Zusammenfassung PF₂(SGeH₃) wurde über die Reaktion von S(PF₂)₂ mit GeH₃Cl dargestellt und mittels IR,Raman, NMR and MS charakterisiert. Es wurden Spaltungs-reaktionen mit Cl₂ und HBr, Donor-Reaktionen des Phosphor und Austausch-reaktionen mit Platinkomplexen untersucht. Die Molekülstruktur von PF₂(SGeH₃) in der Gasphase wurde mittels Elektronendiffraktion bestimmt. Die Hauptparameter (r _a) sind:r(Ge–S) 225,6(4)pm;r(P–S) 211,5(8)pm;r(P–F) 159,0(9)pm; <(GeSP) 99,0(6)° <(SPF) 99,9(4)° <(FPF) 97,0(10)°.

     

Synthesis and crystal structure of 4,4′(1,2-ethanediyldiimino)bis(1,1,1-trichloro-3-penten-2-one)

The preparation, characterization and crystal structure of theSchiff base obtained from 1,1,1-trichloroacetylacetone and ethylenediamine is reported. The structural determination shows that the compound is 4,4(1,1-ethanediyldiimino)bis(1,1,1-trichloro-3-penten-2-one), it suggests that the electron accepting ability of the CCl₃ group induces a larger + charge on the remote carbonyl. In the solid state it occurs in two different conformations and N-H ----O hydrogen bond is present.

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Synthese und Kristallstruktur von 4,4(1,2-Ethandiyldiimino)bis(1,1,1-Trichlor-3-penten-2-on)

Zusammenfassung Es wird über die Darstellung, Charakterisierung und Kristallstruktur derSchiff-Base berichtet, die aus 1,1,1-Trichloracetylaceton und Ethylendiamin erhalten wurde. Die Röntgenstrukturanalyse zeigte, daß es sich um 4,4(1,1-Ethandiyldiimino)bis(1,1,1-trichlor-3-penten-2-on) handelt. Dies impliziert, daß die Elektronacceptorfähgkeit der CCl₃-Gruppe eine größere Partialladung + im entfernteren Carbonyl induziert. Die Verbindung besitzt im Kristall zwei verschiedene Konformationen. Es wurde eine N-H----O-Wasserstoff-brückenbinding festgestellt.

     

Neue Thiophosphate: Die Verbindungen Li6Ln3(PS4)5 (Ln: Y,Gd, Dy,Yb, Lu) und Ag3Y(PS4)2

New Thiophosphates: The Compounds Li₆Ln₃(PS₄)₅ (Ln: Y, Gd, Dy, Yb, Lu) and Ag₃Y(PS₄)₂ The new thiophosphates Li₆Ln₃(PS₄)₅ (Ln: Y, Gd, Dy, Yb, Lu) were synthesized by heating mixtures of Ln, P, S, and Li₂S₄ at 900 °C (100 h) and they were investigated by single crystal X‐ray methods. The compounds with Ln = Y (a = 28.390(2), b = 10.068(1), c = 33.715(2) Å, β = 113.85(1)°), Gd (a = 28.327(2), b = 10.074(1), c = 33.822(2) Å, β = 114.297(7)°), Dy (a = 28.124(6), b = 10.003(2), c = 33.486(7) Å, β = 113.89(3)°), Yb (a = 28.178(3), b = 9.977(1), c = 33.392(4) Å, β = 113.65(1)°), and Lu (a = 28.169(6), b = 10.002(2), c = 33.432(7) Å, β = 113.54(3)°) are isotypic and crystallize in a new structure type (C2/c; Z = 12). Main feature are PS₄ tetrahedra isolated from each other surrounding the Ln and Li atoms via their S atoms. The coordination number of the five crystallographically independent Ln atoms is eight, but the polyhedra are quite different and they are interlinked to larger units extending in [010]. The environment of the Li atoms is irregular and formed by five to six S atoms. The crystal structure is compared with that of Li₉Ln₂(PS₄)₅ (Ln: Nd, Gd). For the synthesis of Ag₃Y(PS₄)₂ (a = 16.874(3), b = 9.190(2), c = 9.312(2) Å, β = 123.17(3)°) a mixture of Y, P, S, and Ag₂S was heated to 700 °C (50 h). The thiophosphate crystallizes in a new structure type (C2/c; Z = 4) composed of isolated PS₄ tetrahedra. The two crystallographically independent Ag atoms are surrounded by four S atoms in the shape of distorted tetrahedra. The Ag(1)S₄ polyhedra are cornershared to strands running along [001], which are linked together via Ag(2)S₄ tetrahedra. The environment of the Y atoms is composed of eight S atoms each building distorted square antiprisms. These polyhedra are connected with each other via common edges to a strand running along [001].     

On the crystal chemistry of three copper(II)-arsenates: Cu3(AsO4)2-III,Na4Cu(AsO4)2, and KCu4(AsO4)3

The three copper(II)-arsenates were synthesized under hydrothermal conditions; their crystal structures were determined by single-crystal X-ray diffraction methods:Cu₃(AsO₄)₂-III:a=5.046(2) Å,b=5.417(2) Å,c=6.354(2) Å, =70.61(2)°, =86.52(2)°, =68.43(2)°,Z=1, space group ,R=0.035 for 1674 reflections with sin / 0.90 Å^–1.Na₄Cu(AsO₄)₂:a=4.882(2) Å,b=5.870(2) Å,c=6.958(3) Å, =98.51(2)°, =90.76(2)°, =105.97(2)°,Z=1, space group ,R=0.028 for 2157 reflections with sin / 0.90 Å^–1.KCu₄(AsO₄)₃:a=12.234(5) Å,b=12.438(5) Å,c=7.307(3) Å, =118.17(2)°,Z=4, space group C2/c,R=0.029 for 1896 reflections with sin / 0.80 Å^–1.Within these three compounds the Cu atoms are square planar [4], tetragonal pyramidal [4+1], and tetragonal bipyramidal [4+2] coordinated by O atoms; an exception is the Cu(2)^[4+1] atom in Cu₃(AsO₄)₂-III: the coordination polyhedron is a representative for the transition from a tetragonal pyramid towards a trigonal bipyramid. In KCu₄(AsO₄)₃ the Cu(1)^[4]O₄ square and the As(1)O₄ tetrahedron share a common O—O edge of 2.428(5) Å, resulting in distortions of both the CuO₄ square and the AsO₄ tetrahedron. The two Na atoms in Na₄Cu(AsO₄)₂ are [6] coordinated, the K atom in KCu₄(AsO₄)₃ is [8] coordinated by O atoms.Die drei Kupfer(II)-Arsenate wurden unter Hydrothermalbedingungen gezüchtet und ihre Kristallstrukturen mittels Einkristall-Röntgenbeugungsmethoden ermittelt:Cu₃(AsO₄)₂-III:a = 5.046(2) Å,b = 5.417(2) Å,c = 6.354(2) Å, = 70.61 (2)°, = 86.52(2)°, = 68.43(2)°,Z = 1, Raumgruppe ,R = 0.035 für 1674 Reflexe mit sin / 0.90 Å^–1.Na₄Cu(AsO₄)₂:a = 4.882(2) Å,b = 5.870(2) Å,c = 6.958(3) Å, = 98.51(2)°, = 90.76(2)°, = 105.97(2)°,Z = 1, Raumgruppe ,R = 0.028 für 2157 Reflexe mit sin / 0.90 Å^–1.KCu₄(AsO₄)₃:a = 12.234(5) Å,b = 12.438(5) Å,c = 7.307(3) Å, = 118.17(2)°,Z = 4, Raumgruppe C2/c,R = 0.029 für 1896 Reflexe mit sin / 0.80 Å^–1.Die Cu-Atome in diesen drei Verbindungen sind durch O-Atome quadratisch planar [4], tetragonal pyramidal [4 + 1] und tetragonal dipyramidal [4 + 2]-koordiniert; eine Ausnahme ist das Cu(2)^{[4 + 1]}-Atom in Cu₃(AsO₄)₂-III: Das Koordinationspolyeder stellt einen Vertreter des Übergangs von einer tetragonalen Pyramide zu einer trigonalen Dipyramide dar. In KCu₄(AsO₄)₃ haben das Cu(1)^[4]O₄-Quadrat und das As(1)O₄-Tetraeder eine gemeinsame O—O-Kante von 2.428(5) Å, was eine Verzerrung der beiden Koordinationsfiguren CuO₄-Quadrat und AsO₄-Tetraeder bedingt. Die zwei Na-Atome in Na₄Cu(AsO₄)₃ sind durch O-Atome [6]-koordiniert, das K-Atom in KCu₄(AsO₄)₃ ist [8]-koordiniert.

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Zur Kristallchemie dreier Kupfer (II)-Arsenate: Cu₃(AsO₄)₂-III, Na₄Cu(AsO₄)₂ und KCu₄(AsO₄)₃

     

Die Kristallstruktur der isotypen Verbindungen KAg(NO3)2, NH4Ag(NO3)2 und RbAg(NO3)2

KAg(NO₃)₂ crystallizes in space group P2₁/a-C _2h ⁵ ,a=13.953,b=4.955,c=8.220 Å, =97.76°,Z=4. X-ray intensities were collected with a two-circle diffractometer. The structure was solved by means of direct methods andFourier syntheses and was refined by the least squares method toR=0.034 with 1346 observed reflexions. ¹ {Ag₂(NO₃)₄}^2–-chains run parallel toy and are linked by potassium ions. Ag shows a distorted tetrahedral coordination with four relatively close O. K is irregularily surrounded by ten O. The isotypic compounds NH₄Ag(NO₃)₂ and RbAg(NO₃)₂ were refined toR=0.032 and 0.035, respectively. The coordination figures are compareable with those in KAg(NO₃)₂.

     

Crystal structure and spectral characterization of dimethylthallium (III) complexes with 2-mercaptonicotinic acid and esters

Synthesis, spectral properties and crystal structure of dimethylthallium(III) complexes with 2-mercaptonicotinic acid (2mna), 2-mercapto-methyl-nicotinate (2mmn), 2-mercapto-ethyl-nicotinate (2men) and 2-mercapto-isopropyl-nicotinate (2min) are reported. The compounds were characterized using IR, multinuclear NMR (¹H,¹³C,²⁰⁵Tl) and mass spectrometry (electrospray, ES-API). The molecular structures of [TlMe₂(2mna)]·H₂O, (1), [TlMe₂(2mmn)], (2), [TlMe₂(2men)], (3) and [TlMe₂(2min)], (4) were determined by the single-crystal X-ray diffraction. In 1, the monodeprotonate O,S-bidentate ligand chelates one dimethylthallium (III) unit and simultaneously bridges (O and S) between two of these organometallic units. The Tl-O1′ and Tl-S″ interactions are leading to polymeric chain linked in a three-dimensional network by the hydrogen bonds formed between the water molecule and the oxygen O (2) atom of the acid. The thallium atom is in a distorted octahedral environment with a [TlC₂O₂S₂] kernel. Compounds 2, 3 and 4 are similar, in all the cases already mentioned the ligand is NH deprotonated and is strongly coordinated to two dimethylthallium (III) units through the N and S atoms. Two additional weak interactions with the O and S atoms lead to a [TlC₂NOS₂] kernel for the metal atom, in which the coordination polyhedron is a very distorted octahedron with the methyl groups occupying the apical positions.     

Syntheses, electrochemistry and crystal structure studies of novel cis-configuration biferrocene trinuclear complexes

The syntheses and characterization of novel biferrocene trinuclear complexes for Schiff base ligand, S-methyl-N-(ferrocenyl-1-methyl-methylidene)dithiocarbazate (hereafter abbreviate as HL), are described. X-ray diffraction studies established the structures of the palladium complex, PdL₂2 and the copper complex, CuL₂3. The geometry of Pd(II) in 2 is close to square planar and in novel cis-configuration with two ferrocene moieties in the same side, while that of Cu(II) in 3 is close to tetrahedral configuration. Electrochemical measurements suggest that the distorted square planar configuration of the Ni(II) and Pd(II) moieties, can effectively transmit the redox effects of the ferrocene moieties, while the distorted tetrahedral configuration of Cu(II) complex can not transmit the redox effects.     

Rare earth-rich cadmium compounds RE 4 TCd (T = Co, Ru, and Rh) with Gd4RhIn type structure

The rare earth-rich cadmium compounds RE ₄ TCd (RE = Y, La–Nd, Sm, and Gd–Tm, Lu; T = Co, Ru, and Rh) were prepared from the elements in sealed tantalum ampoules in an induction furnace. All samples were characterized by X-ray powder diffraction. The structures of Y₄RuCd (a = 1362.5(1) pm), La₄RuCd (a = 1415.9(1) pm), Gd₄RuCd (a = 1368.8(2) pm), La₄CoCd (a = 1417.9(4) pm), Gd₄CoCd (a = 1356.1(1) pm), and Gd₄RhCd (a = 1368.7(1) pm) were refined from single crystal X-ray diffractometer data. The RE ₄ TCd compounds crystallize with the cubic Gd₄RhIn type structure, space group F ${\bar 4}The rare earth-rich cadmium compounds RE ₄ TCd (RE = Y, La–Nd, Sm, and Gd–Tm, Lu; T = Co, Ru, and Rh) were prepared from the elements in sealed tantalum ampoules in an induction furnace. All samples were characterized by X-ray powder diffraction. The structures of Y₄RuCd (a = 1362.5(1) pm), La₄RuCd (a = 1415.9(1) pm), Gd₄RuCd (a = 1368.8(2) pm), La₄CoCd (a = 1417.9(4) pm), Gd₄CoCd (a = 1356.1(1) pm), and Gd₄RhCd (a = 1368.7(1) pm) were refined from single crystal X-ray diffractometer data. The RE ₄ TCd compounds crystallize with the cubic Gd₄RhIn type structure, space group F 3m. The transition metal atoms have tricapped trigonal prismatic rare earth coordination. The trigonal prisms are condensed via common edges, forming a rigid three-dimensional network with adamantane symmetry. Voids in these networks are filled by Cd₄ tetrahedra (304 pm Cd–Cd in Gd₄CoCd) and polyhedra of the RE1 atoms. The crystal chemical peculiarities are briefly discussed. Correspondence: Rainer P?ttgen, Institut für Anorganische und Analytische Chemie, Westf?lische Wilhelms-Universit?t Münster, Correnstrasse 30, 48149 Münster, Germany.     

Infinite octamolybdate chains cross-linked by paramagnetic iron (II) centers

The paper presents a new polymeric polyoxomolybdate cluster with infinite octamolybdate chains cross-linked by iron (II) centers. The layer-type substance contains sodium cations sandwiched between the [Fe(H₂O)₄Mo₈O₂₇]_∞ layers. The structure was determined by single crystal X-ray diffraction analysis. Magnetic properties, due to the presence of paramagnetic iron (II) centers, are presented and discussed.