Tantalum(v) oxoalkoxides. Synthesis and structure

Anodic oxidation of tantalum in isopropyl alcohol or prolonged reflux of an alcohol solution of Ta(OPrⁱ)₅ afford crystalline oxoisopropoxide Ta₂O(OPrⁱ)₈ · PrⁱOH (1). In its molecule, two octahedra about Ta atoms are linkedvia the shared edge [(OPrⁱ)O]. Compound1 is the first example of oxoalkoxide containing such a small number of metal atoms. Unlike the known polynuclear molecules M _n O _m (OR) _p , oxoalkoxide1 is stable in solutions; on transition to the gas phase, this compound is desolvated to form a very stable molecule Ta₂O(OPrⁱ)₈ (apparently, consisting of two octahedra with a shared edge). According to the data of mass spectrometry, analogous molecules exist in the gas phase over Ta(OAlk)₅ (Alk = Me, Et, Prⁱ, or Bu¹¹). When compound1 is heated invacuo (10^–2–10^–3 Torr), Ta(OPrⁱ)₅ is sublimated. Crystals of Ta₇O₉(OPrⁱ)₁₇ (2) were formed upon prolonged storage of solutions of1 in PrⁱOH. Heptanuclear molecule2 consists of two [Ta₄] tetrahedra with a shared vertex. These tetrahedra are additionally linked togethervia one ₃-oxo and two ₂-OPrⁱ groups. Complex2 is a representative of heptameric oxoalkoxides of a new structural type.Deceased in I995.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–131, January, 1996.     

Heterotri- and -tetrametallic alkoxides of chromium(III) containing aluminium(III), gallium(III) and niobium(V)

CrCl₃ · 3THF reacts with two equivalents of potassium alkoxometallates K{M(OPr ⁱ ) _x } [M = Al(A), Ga(B), x = 4; M = Nb(C), x = 6] to give heterobimetallic chloride isopropoxides [Cr{M(OPr ⁱ ) _x }₂Cl(THF)] [M = Al(A – 1), Ga(B – 1), and Nb(C – 1)], in which the replacement of the chloride with an appropriate alkoxometallate (tetraisopropoxoaluminate, tetraisopropoxogallate, or hexaisopropoxoniobate) results in the formation of novel heterotrimetallic derivatives. The 'single pot synthesis of an heterotetrametallic isopropoxide [Cr{Nb(OPr ⁱ )₆}{Al(OPr ⁱ )₄}{Ga(OPr ⁱ )₄}] (7) has been carried out by the sequential addition of (A), (B), and (C) to a benzene suspension of CrCl₃ · 3THF. Alcoholysis of [Cr{Al(OPr ⁱ )₄}₂{Nb(OPr ⁱ )₆}] (1) and [Cr{Al(OPr ⁱ )₄}₂{Ga(OPr ⁱ )₄}] (5) with t-BuOH has also been studied and the derivatives characterized by elemental analyses, molecular weight determinations, spectroscopic [Electronic, i.r., ²⁷Al-n.m.r.] and magnetic susceptibility studies.     

Kristallstruktur von Trisilber(I)amidosulfat-3-Ammoniak-2-Wasser,Ag3SO3N · 3NH3 · 2H2O

An X-ray crystal structure analysis of colourless Ag₃SO₃N · 3NH₃ · 2H₂O was carried out at room temperature:M=504.79, orthorhombic, P2₁2₁2₁,a=6.275 (1) Å,b=11.826 (2) Å,c=14.299 (12) Å,V=1061.10 ų,Z=4,d _x=3.160 Mgm^–3,F(000)=940, Mo K, =0.71069 Å (graphite monochromator), =5.60 mm^–1,R=4.71%,R _w=4.96% (982 reflections, 120 parameters). The structure consists of Ag ribbons; each Ag atom is linearly co-ordinated to two N atoms with distances corresponding to covalent Ag-N bonds; no Ag-O coordination is observed; the N atom of the SO₃N group is surrounded by three Ag atoms; compared to amidosulfuric acid, the SO₃N group shows significant deformation.

     

Kinetics and mechanisms of homogeneous catalytic reactions. Part 3. Regioselective,catalysed [RuH(CO)(NCMe)2(PPh3)2]BF4 reduction of quinoline

Summary A kinetic study of the regioselective homogeneous hydrogenation of quinoline (Q) to 1,2,3,4-tetrahydroquinoline (THQ) was carried out using the cationic complex [RuH(CO)(NCMe)₂(PPh₃)₂]BF₄ (1) as the precatalyst. The experimentally determined rate law wasr = {k ₂ K ₁/(1+K ₁[H₂])}[Ru₀][H₂]², which becomesr = {k ₂ K ₁[Ru₀]–[H₂]² at low hydrogen concentrations (k ₂ K ₁ = 28.5M ^–2 s^–1 at 398 K). The corresponding activation parameters were found to be H = 42 + 6 kJ mol^–1, S = – 115 ± 2JK^–1mol^–1 and G = 92 ± 8 kJ mol^–1. Complex(1) was found to react with Q in CHCl₃ under reflux to yield [RuH(CO)(NCMe)(N-Q)(PPh₃)₂]BF₄ (2) which was also isolated from the hydrogenation runs. These experimental findings, together with the results ofab initio self-consistent-field molecular orbital calculations on the free organic molecules involved, are consistent with a mechanism involving a rapid and reversible partial hydrogenation of(2) to yield the corresponding dihydroquinoline (DHQ) species [RuH(CO)(NCMe)(DHQ)(PPh₃)₂]BF₄ (4), followed by a rate-determining second hydrogenation of DHQ to yield [RuH(CO)(NCMe)(THQ)(PPh₃)₂]BF₄ (3).     

Four novel classes of heterobimetallic isopropoxides of chromium(III)

Four novel classes of hydrocarbon-soluble isopropoxometallates of chromium(III): [Cr{²-Zr(OPr ⁱ )₅}₃], [Cr- {²-M₂(OPr ⁱ )₉}₃] [M = Zr^IV, Sn^IV], [Cr{²-M(OPr ⁱ ) _x Cl}₃] (M = Al, x = 3; M = Nb, x = 5), and [Cr{⁴-Zr₂-(OPr ⁱ )₈Cl}Cl₂]/[Cr{³-Zr₂(OPr ⁱ )₈Cl}{²-Zr₂(OPr ⁱ )₈Cl}Cl] [ ⁿ represents the number of connectivity sites (n = 2, 3, 4) involved in binding Cr^III] have been prepared for the first time and characterized by the elemental analyses, spectroscopic (i.r., electronic) and magnetic susceptibility studies as well as molecular weight measurements. The [Cr{²-Ga(OPr ⁱ )₄}₃] derivative has also been prepared and its magnetic and electronic properties compared with the above four novel types of Cr^III complexes.     

Kristallstruktur von Trimethylisocyanursäure, (CH3NCO)3, und von Trichlorisocyanursäure-1/2-Ethylenchlorid, (ClNCO)3·1/2C2H4Cl2

X-ray crystal structure analyses of (CH₃NCO)₃ (M) and (ClNCO)₃·1/2C₂H₄Cl₂ (C) were carried out at room temperature (MoK, graphite monochromator, =0.71069 Å): 1.M=171.16, monochlinic, P2₁/c,a=14.848 (1) Å,b=13.400 (2) Å,c=8.149 (1) Å, =100.87 (1)°,V=1 592.3 ų,Z=8,F(000)=720,d _x =1.428 Mgm^–3, =76m^–1,R=6.51%,R _w =7.01% (964 reflections, 218 parameters). 2.M=281.89, monochlinic, P 2₁/c,a=9.416 (3) Å,b=5.728 (1) Å,c=18.199 (8) Å, =98.64 (2)°,V=970.4 Å₃,Z=4,F(000)=556,d _x =1.929 Mgm^–3, =1.11 mm^–1,R=3.96%,R _w =3.44% (605 reflections, 132 parameters). The ring systems together with the C atoms of the methyl groups in (M) and with the Cl atoms in (C) are planar and have D_3h-symmetry. Bond lengths and bond angles are discussed with regard to¹⁴N-NQR,³⁵Cl-NQR and vibrational spectroscopic data.

     

Crystal and Molecular Structure of Cu(II) Bis-(2-methoxy-2,6-dimethyl-3-imino-5-heptanonate)

A new compound from the series of alkoxyketoiminates, Cu(II) bis-(2-methoxy-2,6-dimethyl-3-imino-5-heptanonate), has been synthesized and studied by X-ray crystallography. Crystal data for CuO₄N₂C₂₀H₃₆: a=10.154(1), b=9.921(1), c=11.684(2) , =96.17(1)°, space group P2₁/c, Z=2, dcalc =1.226 g/cm³, R=0.037. The structure is molecular and built from isolated trans-complexes. The copper atom has a plane square environment of two oxygen atoms (Cu–O 1.93 ) and two nitrogen atoms (Cu–N 1.90 ). The O–Cu–N chelate angle is 91.7°. The complex has an intramolecular hydrogen bond, N–H...O 2.16 , involving the alkoxy oxygen atom. The molecular packing in the crystal is close to that of copper(II) dipivaloylmethanate. The calculated van der Waals intermolecular interaction energies and thermogravimetric characteristics of the complexes are compared.     

Synthesis,reactivity and x-ray crystal structures of mixed thiazolato- or carboxylato- carbonyl(phosphine) rhenium(I) complexes

Summary The compound [Re(CO)₃(PPh₃)₂Cl] reacts with the lithium salt of thiazole derivatives (L¹H = 2-amino-benzothiazole, L²H = 2–N-methyl-aminothiazole, L³H = 2–N-phenylaminothiazole, L⁴H = 2–N-(4-methoxyphenyl)aminothiazole, L⁵H = 2–N(4-nitrophenyl)aminothiazole) to give [Re(CO)₂-(PPh₃)₂(L)]. The compounds have been characterized by elemental analysis, i.r. and¹H n.m.r. spectra. At room temperature [Re(CO)₂(PPh₃)(L²)] reacts with L⁶H (L⁶H = diphenylacetic acid), to give the carboxylato complex [Re(CO)₂ .The crystal structures of [Re(CO)₂(PPh₃)₂(L²)] (2) and [Re(CO)₂(PPh₃)₂(L⁶)] (6) were determined by x-ray crystallography. [Re(CO)₂(PPh₃)₂(L²)] crystallizes in the monoclinic space group P2₁/m witha = 9.16(1),b= 24.82(2),c =9.12(1) Å, and = 115.81(4)°; D_c = 1.56 g cm^–3for Z = 2.The structure was refined to a final R of 6.4%. The molecules have C_s symmetry. The rhenium atom is six-coordinate with approximately octahedral geometry. The anionic ligand is chelating through the nitrogen atoms and is strictly planar allowing delocalization of the -electron density. [Re(CO)₂(PPh₃)₂(L⁶)] (6) crystallizes in the monoclinic space group P2₁/n witha = 22.203(5),b = 18.651(5),c =10.653(3) Å, = 91.08(3)°, Dc = 1.47 g cm^–3 for Z = 4. The structure was refined to a final R of 4.7%. The complex is monomeric and the rhenium atom is distorted octahedral with two mutuallytrans PPh₃ ligands, twocis CO ligands and one chelating Ph₂CHCO ₂ ^– ion.     

Crystal structure of Li2Cu3(SeO3)2(SeO4)2

Summary Single crystal X-ray data of the hydrothermally grown new phase Li₂Cu₃(SeO₃)₂(SeO₄)₂ were measured with a four-circle diffractometer up to sin /=0.81 Å^–1 [I2/a,Z=4,V=1175.5 ų,a=16.293(6),b=5.007(2),c=14.448(6) Å, = 94.21(1)°]. The structure was determined by direct and Fourier methods and refined toR=0.034,R _w =0.027 for 2 086 independent reflections.Cu(1)^[4+1]O₅ forms a tetragonal pyramid, Cu(2)^{[4 + 2]}O₆ is a strongly elongated octahedron. The Li atom is surrounded by four O atoms forming a distorted tetrahedron. Se(IV)O₃ and Se(VI)O₄ groups are in accordance to literature, mean Se-O bond lengths are 1.714 and 1.644 Å.

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Die Kristallstruktur von Li₂Cu₃(SeO₃)₂(SeO₄)₂

Zusammenfassung Einkristall-Röntgendaten der hydrothermal gezüchteten neuen Phase Li₂Cu₃(SeO₃)₂(SeO₄)₂ wurden mit einem Vierkreisdiffraktometer im Bereich bis zu sin /=0.81 Å^–1 gemessen [I2/a,Z=4,V=1175.5 ų,a=16.293(6),b=5.007(2),c=14.448(6) Å, =94.21(1)°]. Die Kristallstruktur wurde mittels direkter und Fourier-Methoden bestimmt und für 2 086 unabhängige Reflexe zuR=0.034,R _w =0.027 verfeinert.Cu(1)^[4+1]O₅ bildet eine tetragonale Pyramide, Cu(2)^[4+2]O₆ ist ein stark verlängertes Oktaeder. Das Li-Atom ist von vier O-Atomen in Gestalt eines verzerrten Tetraeders umgeben. Die Se(IV)O₃-und Se(VI)O₄-Gruppen entsprechen der Literatur, die mittleren Se-O-Abstände betragen 1.714 und 1.644 Å.

     

Preparation,characterization and a kinetic study oftrans-[Ru(NH3)4L(H2O)](PF6)2 [L=PPh3, AsPh3, or SbPh3]

Summary The complexestrans-[Ru(NH₃)₄(H₂O)PPh₃](PF₆)₂ and [Ru(NH₃)₅L](PF₆)₂, (L=AsPh₃ or SbPh₃) have been isolated and characterized by microanalysis, cyclic voltammetry and ultraviolet-visible spectroscopy. The specific rate constants for the aquation of [Ru(NH₃)₅L]²⁺ totrans-[Ru(NH₃)₄L(H₂O)]²⁺ are (2.5±0.1)×10^–5s^–1 and (1.8±0.1)×10^–5s^–1 for L=AsPh₃ and SbPh₃, respectively, at 25.0±0.1°C; =0.10 mol dm^–3, NaO₂CCF₃. Under the same conditions, the second-order rate constants for the substitution of water intrans-[Ru(NH₃)₄(H₂O)L]²⁺ by isonicotinamide (isn) are 1.2±0.1, (6.3±0.3)×10^–2 and (3.8±0.2)×10^–2 m ^–1s^–1 for L=PPh₃, AsPh₃, and SbPh₃, respectively, suggesting that the order of decreasingtrans-effect is: PPh₃AsPh₃>SbPh₃. The formation constants for thetrans-[Ru(NH₃)₄L(isn)]²⁺ complexes are 75±3, (1.40±0.01)×10³ and (1.80±0.02)×10³M^–1 for L=PPh₃, AsPh₃, and SbPh₃, respectively, suggesting that the order of increasingtrans-influence is: SbPh₃3PPh₃.     

Observedtrans influence of donor atoms in monocharged bidentate ligands: Crystal structure of the acetone solvate of 2-carboxyquinolinatocarbonyltriphenylphosphinerhodium(I)

Summary 2-Carboxyquinolinatocarbonyltriphenylphosphinerhodium(I), [Rh(Quin)(CO)(PPh₃)], was prepared by replacement of CO by PPh₃ in the corresponding dicarbonyl. The compound crystallizes in the triclinic space group Åb=17.168(6) Å,c=9.254(5) Å, =101.49(5)°, =95.74(4)°, =98.41(4)°, d_cxp=1.45g cm^–3 and Z=2. The crystal structure was dermined from 3496 observed reflections. The final R value was 0.061. This structure determination indicates that the nitrogen atom of the chelate ring has the largesttrans influence since the carbonyl grouptrans to this atom was substituted by the PPh₃ ligand. The effects of different donor atoms in bidentate ligands, as well as the ring size of the chelate ring, on the relativetrans influence of the donor atoms are discussed.     

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

     

Darstellung und Kristallstruktur von Pb2(NO2)(NO3)(SeO3)

Crystals of Pb₂(NO₂)(NO₃)(SeO₃) were synthesized by partial reduction of nitrate ions with native copper under hydrothermal conditions. The crystal structure [a=5.529 (2) Å,b=10.357 (3) Å,c=6.811 (2) Å, space group Pmn2₁,Z=2] was determined from 1 707 independent X-ray data up to sin /=0.81 Å^–1 and was refined toR _w =0.028. The Pb(1) atom is ten coordinated to O atoms [Pb(1)-O from 2.51 Å to 2.96 Å], the Pb(2) atom has three nearest O atoms [Pb(2)-O=2.41 Å (1 ×) and 2.45 Å (2 ×)] and six next-nearest O atoms [Pb(2)-O from 2.80 Å to 3.22 Å].

Herrn Prof. Dr.K. Komarek zum 60. Geburtstag gewidmet.     

Di- and tri-nuclear osmium carbonyl chloride complexes: x-ray structures of Os2(CO)8Cl2 and Os3(CO)12Cl2

Summary Os₂(CO)₈Cl₂ (1) is orthorhombic P2₁2₁2₁ witha=9.3599(9),b=9.879(2),c=16.014(3), V=1480³, D_c=3.03 Mgm^–3 for Z=4. Structure solved by Patterson methods. Final R=0.038, R_w=0.038 [w=(²F)] for 1270 observed reflections and 141 parameters. Os₃(CO)₁₂Cl₂ (2) is monoclinic C2/m witha=12.105(3), b=10.612(3),c=8.798(1) , =117.02(2)°, V=1006³, D_c=3.22 Mgm^–3 for Z=2. Structure solved by Patterson methods. Final R=0.036, R_w=0.037 (w=(²F)^–) for 821 observed reflections and 75 parameters.Complex(1) has an osmium-osmium single bond 2.897(1), with the chloride ligands in equatorial positions,(2) has a linear triosmium chain with osmium-osmium single bonds 2.893(1) and the chloride ligands occupy equatorial sites on the terminal osmium atoms. Both(1) and(2) are isostructural with their osmium carbonyl iodide analogues.     

Synthesis and crystal and molecular structure of Mo4O(OCH2But)10(py): A 12-electron butterfly cluster

From the reaction between Mo₂(OCH₂Bu^t)₆ and water (1/2 equiv) in toluene solution in the presence of pyridine the oxo-alkoxide tetranuclear cluster Mo₄O(OCH₂Bu^t)₁₀(py) has been isolated as a dark crystalline compound. Crystal data at –121°C:a=24.762(12) Å,b=24.799(9) Å,c=23.021(9) Å,Z=8,d _caled=1.27 g cm^–3 in space group 14/m. The compound contains a Mo₄ butterfly with a hinge angle of 137° between the two Mo₃ triangles. The molecule has a crystallographically-imposed mirror plane of symmetry that contains the wing-tip Mo atoms. One wing-tip Mo atom is in an octahedral environment being bonded to two terminal and two-bridging OR ligands, and one pyridine ligand that is trans to a ₃-oxo bridge. The other Mo atoms are each coordinated to only four oxygen atoms. The backbone Mo atoms have one terminal and two bridging OR ligands and form one bond each to the ₃-oxo group. The other wing-tip Mo atom is coordinated to two terminal and two bridging OR groups. The five Mo-Mo distances span the range 2.43–2.59 Å. The¹H and¹³C{¹H} NMR spectra in benzene-d₆ are consistent with the presence of this structure in solution. The present results are compared to earlier findings for 12-electron alkoxide clusters of Mo and W.     

[Et3PH][W4O3Cl7(PEt3)3]. A 12-electron tetrahedral tungsten cluster with an interesting arrangement of ligands

From the reaction between W₂Cl₆(PEt₃)₂ and H₂O in tetrahydrofuran the dark green crystalline compound [Et₃PH][W₄O₃Cl₇(PEt₃)₃] was obtained and characterized by X-ray crystallography. At –155° the cell dimensions werea=b=c=20.392(3) Å,Z=8,d _calcd=2.36 g cm^–3 in the space group I23. The compound is a triethylphosphonium salt of the [W₄O₃Cl₇(PEt₃)₃]^– anion. The latter contains a tetrahedron of tungsten atoms with W–W=2.61 Å (ave) and may be viewed as a W₃(-Cl)₃Cl₃(PEt₃)₃ cluster capped by ad ⁰-[WO₃Cl]^– unit and this has proved useful in examining the bonding within the cluster by use of the M.O. calculational method of Fenske and Hall. The cluster anion has crystallographically imposed C_3v symmetry. Theoxo-groups bridge the tungsten atoms in a notably asymmetric manner W–O=1.87(2) Å and 2.04(2) Å with the shorter distances being involved with the capping [WO₃Cl]^– unit. The W–P bonds lie in the W₃(₃-Cl)₃ plane and the three terminal W–Cl bonds are trans to theoxo-bridges.     

The crystal structure of tetraphenylphosphonium tetracyanohydroxooxorhenium(V)

Summary The crystal structure of (PPh₄)₂[ReO(OH)(CN)₄]·5H₂O has been determined from three-dimensional x-ray diffraction data. The light brown crystals are monoclinic, space group P2₁/n, with cell dimensionsa=16.753(2),b=19.928(2),c=15.338(2) Å and =101,894(1)°,z=4, D_m=1.45(1) g cm^–3. The anisotropic refinement of the 6088 observed reflections converged to R=0.077.The [ReO(OH)(CN)₄]^2– ion has a distorted octahedral geometry. Bond distances: Re =1.70(1), Re–OH=1.90(1) and ReC_av=2.12(2) Å. The Re atom is displaced by 0.08 Å out of the plane formed by the four carbon atoms towards the terminal oxo ligand.     

Monomeric [Ni(2,2"-Bipy){(i-C4H9)2PS2}2] and [Ni(Pz)2{(i-C4H9)2PS2}2] and Polymeric [Ni(Pz){(i-C4H9)2PS2}2]nComplexes (Pz = Pyrazine): Synthesis,Structures, and Properties

Diamagnetic [Ni(i-Bu₂PS₂)₂] compound (I) in ethanol reacts with 2,2"-bipyridine or pyrazine to give the paramagnetic complexes [Ni(2,2"-Bipy)(i-Bu₂PS₂)₂] (II), [Ni(Pz)₂(i-Bu₂PS₂)₂] (III), and [Ni(Pz)(i-Bu₂PS₂)₂] _n (IV) (_eff= 2.91–3.12 _B). Single crystals of IIwere grown for X-ray diffraction study. The crystals are monoclinic, a= 14.669(3) Å, b= 19.693(4) Å, c= 12.155(2) Å, = 107.51(3)°, V= 3348(1) ų, Z= 4; _calcd= 1.257 g/cm³, space group P2₁/c. The structure is built from monomeric molecules. The coordination polyhedron of the Ni atom is a distorted octahedron formed by four S atoms of two bidentate chelating i-Bu₂PS^– ₂ligands and by two N atoms of bidentate cyclic 2,2"-Bipy. Preliminary data for complexes IIIand IVindicate that they also contain an octahedral NiN₂S₄fragment. The structures of complexes I(square planar) and ofII–IV(octahedral) were confirmed by data from electron spectroscopy. Electronic absorption spectra were used to determine the rankings of the i-Bu₂PS^– ₂ions and Pz on a spectrochemical scale.     

Diaqua[N,N-di(2-carboxyethyl)-o-anisidinato]copper(II) Dihydrate [Cu(o-Andp)(H2O)2] · 2H2O: Synthesis and Crystal Structure

Crystals of [Cu(o-Andp)(H₂O)₂] · 2H₂O (where o-Andp^2–is -anisidine-N,N-di-3-propionate) were synthesized and studied using X-ray diffraction analysis. The crystals are triclinic: a= 12.063(1) Å, b= 12.483(3) Å, c= 13.586(2) Å, = 91.29(1)°, = 111.67(1)°, = 104.00(1)°, V= 1830.5(5) ų, space group P , Z= 2, and R= 0.0528 for 5965 reflections with I2(I). The two crystallographically independent complexes are isostructural. The tetragonal–bipyramidal coordination of copper(III) involves three O atoms, the N atom of the tetradentate ligand o-Andp^2–, and two O atoms from water. The aminodipropionate group of the ligand (average Cu–O 1.939 Å and Cu–N 2.051 Å) and one of the coordinated water molecules (Cu–O(w) 1.991 Å) lie in the equatorial plane. The second water molecule (Cu–O(w) 2.32 Å) and the methoxy O atom of o-Andp^2–(Cu–O 2.37 Å) are in the apical positions of the bipyramid.     

Kristallstruktur von Trisilber(I)amidosulfat Monohydrat,Ag3SO3N · H2O

An X-ray crystal structure analysis of yellow Ag₃SO₃N · H₂O was carried out at room temperature:M=435.69, monoclinic, P2₁/n,a=11.628 (5) Å,b=8.058 (4) Å,c=12.034 (5) Å, =86.49 (3)°,V=1125.5 ų,Z=8,d _x =5.142 Mgm^–3, MoK, =0.71069 Å (graphite monochromator), =10.5 mm^–1,R=5.44%,R _w =5.85% (877 reflections, 118 parameters). The structure contains Ag planes with Ag-Ag distances shorter than in metallic silver. The nitrogen atoms of the SO₃N anion are covalently bonded to 4Ag atoms of these Ag planes, thus assuming the extraordinary coordination number of 5. The five crystallographically independent Ag atoms forming the Ag planes have approximate linear N-Ag-N coordination. In addition, the structure contains two Ag atoms which are ionically coordinated to 4 resp. 5O atoms of SO₃N and water. The colour-structure correlation of Ag(I) compounds with colourless anions is discussed.

Herrn Prof. Dr. mult.V. Gutmann zum 65. Geburtstag gewidmet.