bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kristallstrukturen und Schwingungsspektren zweier isomerer Oktadekawolframatodiarsenate, (NH4)6As2W18O62 ·nH2O/ Crystal Structures and Vibrational Spectra of Two Isomers of Octadecatungsto-diarsenate (NH4)6As2W18O62 · nH2O
Authors: Neubert Holger , Fuchs Joachim 
Published: March 2015

Abstract
Six possible structures of As2W18O62
6- are discussed, and an exact nomenclature is proposed. The structures of the isomeric title compounds (I and II) were determined by X-ray diffraction. I crystallizes in space group P I with lattice parameters a = 12.965(4), b = 14.803(5), c = 18.515(6) Å; a = 96.280(23)°, β = 91.420(25)°, γ = 115.320(25)°. The anion has the configuration first observed in K6P2W18O62 · 14H2O (Dawson-structure). II was not known until now. It crystallizes in the trigonal space group R3 with lattice parameters a - b - 37.857(32). c = 13.108( 13) Å; α = β = 90°, γ = 120°. The structure of this anion differs from the Dawson-structure by the 60° rotation of both polar groups of three WO6-octahedra (β-type), followed by the 60° rotation of one of the two new AsW9O31-units. Both rotations are about the 3-fold axis. The anion is centrosymm etric. Vibrational spectra and preparation of the isomers are described.
Nitrosyl- und Nitrokomplexe des Cobalts, 1. Mitteilung Kristallstruktur von Co(acac)2(NO) und seinen Oxidationsprodukten Co(acac)2(NO2)(H2O) und Co5(acac)8(μ3-OH)2(μ-N ,O–NO2)2/ Nitrosyl and Nitro Complexes of Cobalt, Part 1 Crystal Structure of Co(acac)2(NO) and its Oxidation Products Co(acac)2(NO2)(H:O) and Co5(acac)8(μ3-OH)2Cu- N,O-NO2)2
Authors: Englert Ullrich , Strähle Joachim 
Published: March 2015

Abstract
The compound Co(acac)2(NO) (1) crystallizes in the triclinic space group P1̄ with lattice constants« - 806.4(2), b = 1095.3(7), c - 776.4(3) pm, α = 105.62(4), β = 113.18(2), γ = 75.14(3)°, Z - 2. The Co atom exhibits a square pyramidal coordination with the chelating acac ligands in the basis and the NO group at the apex, the angle Co - N - O being 120.4°. 1 is very sensitive to oxygen and, with air in aqueous acetone, yields Co(acac)2(NO2)(H2O) (2). 2 crystallizes in the monoclinic space group P21/n with lattice constants a = 704.9(9), b = 1314.2(7). c - 1451.3(7) pm. β = 97.93(2)°, Z = 4. The structure of 2 is built up by octahedral complexes with the aquo and the nitro ligand in trans positions. A CH2Cl2 solution containing 1 and Co(acac)2 reacts with O2, to form CO5(acac)8(μ-OH )2(μ - N, O -NO;)2 (3) which precipitates on cooling to - 30°C and addition of hexane. 3 crystallizes in the monoclinic space group P2/n with a = 2227(1), b = 1128.9(7), c = 2293(2) pm, β = 104.79(3)°, Z - 4. The structure consists of pentanuclear complexes with C2 symmetry. Two Cortriangles sharing one corner are each bridged by one μ3 - OH -group. The NO2 ligand functions as a N,O-bonded bridging group. The acac ligands complete the coordination of the Co-atoms to distorted octahedra.
Darstellung und Reaktionen von 2-Alkoxy-1,3-bis-(trimethylsilyloxy)-2 H-isoindolen/ Preparation and Reactions of 2-Alkoxy-1,3-bis-(trimethylsilyloxy)-2H-isoindoles
Authors: Troll Theodor , Schmid Klaus , Rasch Ingrid 
Published: March 2015

Abstract
The electrochemical reductive silylation of N-alkoxyphthalimides leads to 2-alkoxy-1,3-bis- (trimethylsilyloxy)-isoindoles, which can be trapped by cycloaddition reactions with dienophiles like methyl acrylate and dimethyl acetylenic dicarboxylate. The unstable primary cycloadducts form naphthoquinones and dihydronaphthoquinones as monoxime derivatives. All oximes form syn and anti isomers.
Aminoalkylierung von Enhydrazinonen/ Aminoalkylation of Enhydrazinones
Authors: Möhrle Hans , Arz Petra 
Published: March 2015

Abstract
Enhydrazinones. prepared from dimedone and N,N-disubstituted hydrazines, react with formaldehyde and secondary amines to C-aminoalkyl-derivatives, pyrazolinium betaines and methylenebis( enhydrazinones). With better yields the C-Mannich products result from the reaction with methyleniminium salts. The enhydrazinones give with two moles of formaldehyde and primary amines the corresponding tetrahydropyrimidines.
Disodium 5-Cyanoisothiazoledithiolate as a Starting Material for Preparation of New Conductive Solids
Authors: Papavassiliou G. C. , Mousdis G. A. , Gionis V. , Zambounis J. S. , Yiannopoulos S. Y. 
Published: March 2015

Abstract
Starting from disodium 5-cyanoisothiazoledithiolate som e new substituted derivatives of the tetrathiafulvalene and some metal 1,2-dithiolenes with at least an isothiazolo-ring have been prepared. From these com pounds a number of conductive cation radical salts have been obtained.
1.6-Diaminohexan als Schablonenverbindung in der Synthese von Zeolith ZSM-5 / 1.6-Diaminohexane as Template in the Synthesis of Zeolite ZSM-5
Authors: Lermer H. , Unger K. K. 
Published: March 2015

Abstract
A mixture characterized by the molar ratios of H2O/SiO2 = 20, SiO2/Al2O3, = 120, Na2O/SiO2 = 0.3 and 1.6 diaminohexane (DAH) as template was reacted at 182 °C. Dependent on the reaction time, the ratio of OH- /SiO2 and DAH/SiO2 ZSM-5 was crystallised with α-quartz as by-product. The materials were characterized by X-ray diffraction, scanning electron microscopy, infrared spectroscopy, thermogravimetry and differential thermal gravimetry.
Sr3GaSb3 und Sr3InP3, zwei neue Zintlphasen mit komplexen Anionen / Sr3GaSb3 and Sr3InP3, Two New Zintl Phases with Complex Anions
Authors: Cordier Gerhard , Schäfer Herbert , Stelter Michael 
Published: March 2015

Abstract
The new compound Sr3GaSb3 crystallizes in the monoclinic system, space group P21/n (No. 14) with the lattice constants: a = 1176.2(4) pm, b = 1450.9(5) pm, c = 1174.9(4) pm, β = 110.0(1)°. In the structure distorted GaSb4 tetrahedra are connected by common corners, to give strands with groups of four tetrahedra as the repeating unit. The new compound Sr3InP, crystallizes in the orthorhombic system, space group Pnma (No. 62) with the lattice constants: a = 1280.9(5) pm, b = 433.0(2) pm, c =1386.6(5) pm. In the structure distorted InP4 tetrahedra are connected by common corners, to give strands with one tetrahedron as the repeating unit. Both compounds are Zintl phases.
Vibronische Kopplung und dynamisch verzerrte Strukturen in Hexahalogenotelluraten(IV): Ergebnisse aus Tieftemperatur-Röntgenbeugungsuntersuchungen (300—160 K) und aus FTIR-spektroskopischen Experimenten (300—5 K) [1] / Vibronic Coupling and Dynamically Distorted Structures in Hexahalogenotellurates(IV): Low Temperatur X-Ray Diffraction (300—160 K) and FTIR-Spectroscopic (300—5 K) Results [1]
Authors: Abriel Walter , Zehnder Ernst-Jürgen 
Published: March 2015

Abstract
From theoretical considerations a dynamically distorted octahedron as a result of vibronic coupling between the ground state and the first excited state should exist for 14 electron AX6E systems like TeX6
2- . A high symmetry crystal field yielding at least a center of symmetry for the Te position stabilizes this fluctuating structure, otherwise statical distortion will be observed. From X-ray diffraction experiments on antifluorite type compounds A2TeX6 (A = Rb. Cs: X = Cl, Br) the averaged structure (m3̅m symmetry) of the anions was found even at very low temperatures. The thermal parameters are not significantly different from those of similar SnX6
2 compounds. Distortions therefore are very small and are evident from FTIR spectroscopic meas­urements only. Here very broad T1u-deformation vibration bands are observed down to tempera­tures <10 K without splitting: Astatically distorted species could not be frozen out. In contrast to XeF6 for TeX6
2- the energy gap between the threefold, fourfold or sixfold minima of the potential surface (according to the symmetry of one component of the T1u-vibration) is very small and shifted to temperatures lower than reached with the devices used for these experiments.
Synthesis and Structural Systematics of First-Row Transition Metal Complexes with 2-[Bis(benzimidazol-2-ylmethyl)amino]ethanol
Authors: Takahashi Kazuhiro , Nishida Yuzo 
Published: March 2015

Abstract
A nickel(II) complex with (bbimae) (= 2-[bis(benzimidazol-2-ylmethyl)amino]ethanol), [Ni(bbimae)(NCS)2] · H2O (1) and an oxovanadium(IV) complex, [VO(bbimae)(NCS)2] · dma (dma = N.N-dimethylacetamide) (2) have been prepared and their crystal structures determined by X-ray diffraction. Crystal data for 1 at 293 K: a = 13.334(2). b = 17.048(2), c = 10.3829(9) Å, space group P212121, Z = 4, and dcalcd = 1.41 gcm-3. Crystal data for 2 at 293 K: a = 14.099(2). b = 14.998(4), c = 14.051(2) Å, β = 107.634(9)°, space group P21/c, Z = 4, and dcalcd = 1.36 gcm-3. In the nickel(II) complex, (bbimae) functions as a tetradentate ligand, and the geometry around Ni(II) ion is best described as distorted octahedral. The structure is very similar to those of the correspond­ing Co(II) and Mn(II) complexes. In the case of 2, which is also distorted octahedral, (bbimae) is a tridentate ligand without the coordination of the alcohol group. The M-N (benzimidazole) distances are in the range of 1.95-2.18 Å, and also observed for other first-row transition metal complexes with (bbimae). and differ in the order V(IV) < Mn(II) > Co(II) > Ni(II) > Cu(II). consistent with effective ionic radii of the metal ions. Comparison of the structural parameters of these complexes with those of the metal ions in biological systems has supported the usefulness of the tripod-like ligands to synthesis model compounds for biological systems.
Chemie an starren Grenzflächen, 8. [1] Kinetik der Heterogenumsetzung kovalent über Spacer an Aerosil gebundener Aminogruppen (Aminoaerosil) mit homogen gelösten Isothiocyanaten / Chemistry on Rigid Interfaces, 8 . [1] Kinetics of Suspensions of Aminoaerosil (Aerosil Covalently Linked with 3-Aminopropylgroups) with Isothiocyanates in Homogeneous Solution
Authors: Horner L. , Roth W. 
Published: March 2015

Abstract
In aminoaerosil, the products of the reaction of γ-aminopropyltriethoxysilane with aerosil. an intraparticular interaction of the basic amino groups with the acidic silanol groups is observed. This behaviour was established a) by adsorption experiments using n-butylamine on aerosil. resp. aminoaerosil of different support density, and b) by microcalorimetric determination of the adsorption energy of acetonitrile using aerosil and aminoaerosils of different support density as substrates.
Aminoaerosils react with isothiocyanates according to (I) with formation of covalently linked thiourea groups. Fig. 3 and Fig. 5 (with trimethylamino) show the time-turnover curves of aminoaerosils of different support density with phenylisothiocyanate. The influence of the tem­perature on the thiourea formation is demonstrated in Table III. Depending on the polarity and the size of the ligands R. the isothiocyanates react with different reaction rates with aminoaerosil (Fig. 6). Aminoaerosils with different coverage density, but with an equal molarity of amino groups and varying specific surfaces, react non-uniformly with phenylisothiocyanate (Table IV).
The comparison of the reaction of phenylisothiocyanates a) with heterogeneously by suspended aminoaerosil and b) with n-butylamine in homogeneous solution, both with equal molar amounts of NH2, shows characteristic differences (Fig. 8).
The amount of the covalently linked NH2-groups in aminoaerosils can be determined using Sanger’s reagent.
Purification and Partial Characterization of Rat Liver Lipoxygenase
Authors: Macias Pedro , Pinto M. Carmen 
Published: March 2015

Abstract
Lipoxygenase was purified from rat liver cytosolic fraction by a method involving two successive chromatographic steps on Sephacryl S-200 and Phenyl Sepharose CL-4B. The enzyme has a molecular weight of 96 Kdal and it seems to be composed of two identical subunits. Chromatofocusing of the enzyme revealed a single band of activity at pi 6.3. The enzyme activity of the purified fraction showed maximum activity at pH 7.0 with a Km for linoleic acid of 1.4 μM and is competitively inhibited by the specific lipoxygenase inhibitor nordihydroguaiaretic acid. The purified enzyme shows absorption and fluorescence spectra similar to those of lipoxygenase from other sources. However, the molecular weight of lipoxygenase purified from liver is found to be different from that of the enzyme from polymorphonuclear leukocytes. It is suggested that there are different isoenzymes of lipoxygenases in mammals.
The Structure of the Tetraphenyldithioimidodiphosphinate Ion
Authors: Cea-Olivares Raymundo , Nöth Heinrich 
Published: March 2015

Abstract
The potassium 18-crown-6 ether salt of the title anion has been prepared. It crystallizes in the monoclinic system, space group C2/c, with four molecules in the unit cell. The anion possesses a crystallographically imposed C2 symmetry. The PN bond length of the anion is shorter and the PS bond longer than in the neutral molecule [Ph2P(S)]2NH , while the PNP bond angles are essentially the same.
Anwendung der 15N-NMR-Spektroskopie zur Charakterisierung reaktiver, koordinativ ungesättigter Zinn-, Bleiund Phosphor-Stickstoff-Verbindungen / Application of 15N-NMR Spectroscopy to the Characterization of Reactive, Coordinatively Unsaturated Tin-, Lead- and Phosphorus-Nitrogen Compounds
Authors: Stader Carin , Wrackmeyer Bernd 
Published: March 2015

Abstract
The basic INEPT pulse sequence proved most useful for recording 15N NMR spectra at natural abundance of bis(amino)stannvlenes (1). -plumbylenes (2) and of imino-amino-λ2-phosphanes (3), where the nitrogen atoms carry bulky substituents like Me3Si-, t-Bu-, 2.4.4-trimethyl-2- pentyl-groups (t-Oct-groups) or are part of the 2.2.6.6-tetramethylpiperidinyl group. The sensitiv­ity of this technique is proved by the observation of 117/119Sn or 207Pb satellites owing to spin-spin coupling constants 1J(117/119Sn15N) and 1J(117/119Pb15N), respectively. NMR data of bis[bis(trimethylsilyl)methyl]tin (4) are reported in order to corroborate the arguments for the interpretation of the δ(15N) and 1J(119Sn15N) data. The 15N NMR data of the λ2-phosphanes (3) indicate a bonding situation similar to that in triazenes.
Synthese einer chiralen Thienamycin-Vorstufe / Synthesis of a Chiral Thienamycine Intermediate
Authors: Martin Hubert , Herrmann Rudolf , Ugi Ivar 
Published: March 2015

Abstract
A key intermediate of Kametani’s total synthesis of racemic thienamycine has now been prepared in chiral form via a 1.3-dipolar cycloadduct of a chiral nitrone and benzyl crotonate.
μ-Nitridokomplexe von Wolfram(V) / μ-Nitrido Complexes of Tungsten(V)
Authors: Fenske Dieter , Godemeyer Thomas , Dehnicke Kurt 
Published: March 2015

Abstract
W2NCl7 has been prepared by the reaction of tungsten pentachloride with the bromide of Millon's base, [Hg2N]Br, in boiling CCl4. The product forms a dark brown, moisture sensitive crystal powder (μeff = 0.7 B.M. at 21 °C). With phosphoryl chloride, the complex W2NCl7·2 POCl3 is formed. The reaction with chlorine leads to the mixed-valenced W(V)/W(VI) complex W2NCl8 (μeff = 0.5 B.M. at 22 °C), which reacts with tetraphenylphosphonium chloride in CH2Cl2 to form (PPh4)2[W2NCl10] ·2CH2Cl2. The reactions of W2NCl7 with PPh4Cl in molar ratios in CH2Cl2 solution lead to several complexes; one of them was identified bv X-ray diffraction methods to be (PPh4)2[W3Cl9(μ3-N)(0)(μ2-NCl)]2 ·1,5 CH2Cl2, which forms black crystals. The compound crystallizes monoclinically in the space group P21/n with two formula units per unit cell (7318 observed, independent reflexions, R = 0.083). The lattice dimensions are (20 °C): a = 994.4; b = 2673; c = 1518.2 pm; β = 101.00°. The compound consists of PPh4
⊕ cations and centrosymmetric anions [W3Cl9(μ3-N)(O)(μ2-NCl)]2
2⊕. The tungsten atoms form a scalene triangle with WW bond lengths of 282 and 278 pm, respectively. The hypothenuse of this triangle is a nearly linear W - N -W bridge with WN distances of 199 and 182 pm. One of the WW edges is bridged by a μ-NCI group with WN bond lengths of 196 und 189 pm. respectively.
Lineare Oligophosphaalkane, XX [1]: Alkalimetall-und Trimethylsilylderivate PH-funktioneller Methylenbisphosphane / Linear Oligophosphaalkanes, XX [1]: Alkali Metal and Trimethylsilyl Derivatives of PH-Functional Methylenebisphosphanes
Authors: Gol Franjo , Hasselkuß Gerd , Knüppel Peter C. , Stelzer Othmar 
Published: March 2015

Abstract
The synthesis of the trimethylsilyl derivatives of the PH-functional methylenebisphosphanes, R2-n(Me3 Si)nP-CH2 -PR(SiMe3) (R = Me, iPr, tBu, Ph, 2.4.6-Me3C6H2 ; n = 0.1) is reported. In the Li-phosphides R2-nLinP - CH2 - PLiR used as reactive intermediates, a monomer-oligomer association equilibrium causes a rapid Li-exchange as indicated by the solvent and temperature dependent 31P{1H} and 7Li NMR spectrum of (iPr)2 P-CH2 -P(iPr)Li in various solvents (Et2O, THF and MTHF) in the temperature range from 30 to -110 °C. For the syntheses of the Me-and Ph-substituted PH-functional methylenebisphosphanes R2P-CH2 -PRH and RHP-CH2 -PRH (R = Me, Ph) the chlorophosphane CKP -CH2 -PCl2 is used as a starting material. Bifunctional substituents (Ph -N̍-N̍ -Ph and Me -N̍-CO-N̍-Me) are employed for the first time as protecting groups to block one or two PCl-functions in Cl2P-CH2-PCI2,. Cleavage of the PN-bonds in the five membered ring systems

(R = Me, Ph) with HCl affords the P-substituted methylenebis-chlorophosphanes RClP-CH2 - PClR in satisfactory yields.
The compounds have been characterized by 1H, 13 C{1H} and 31P{1H} NMR spectroscopy. With-in homologous substitution series of methylenebisphosphanes, e.g. R2P-CH2-PR2-nHnthe coupling constants 2J(PP) seem to reflect conformational changes at the PCP-skeleton.
Synthese und Kristallstruktur von t-Butyloxyzinn(II)chlorid / Synthesis and Crystal Structure of t-Butyloxytin(II) Chloride
Authors: Zybill Chr. , G. Müller G. 
Published: March 2015

Abstract
t-Butyloxytin(II) chloride (1) is prepared from SnCl2 and KO-z-Bu at -60 °C in tetrahydrofuran. Above -30 °C a reversible dismutation into SnCl2 and [(t-BuO)2Sn] is observed in THF. For this process Δ G = +38 kJ/mol is estimated from NMR data. Compound 1 is a centrosymmetric dimer in the solid state with bridging O atoms (Sn-O 2.153(2)/2.156(2) Å, O-Sn-O 73.0(1)°, Sn-O-Sn 107.0(1)°). Due to the acute intraring bond angles at Sn. the O···O distance across the four-membered ring is relatively short (2.563(3) Å). The dimers are very loosely connected to chains by bridging THF molecules.
Synthese und Eigenschaften einiger Silylethinylsilane; Molekülstruktur von Tetrakis(trimethylsilylethinyl)silan / Synthesis and Properties of Some Silylethynylsilane; Molecular Structure of Tetrakis(trimethylsilylethynyl)silane
Authors: Schmidbaur Hubert , Ebenhöch Jan 
Published: March 2015

Abstract
Trimethylsilylethine (1) has been prepared from C2H2, sodium and Me3SiCl in anisole. The product can be converted into a Grignard reagent Me3SiC≡CMgCl using iPrMgCl. This reagent yields the compounds Me3SiC≡CSiH3, (Me3SiC≡C)2SiH2, (Me3SiC≡C)3SiH, and (Me3SiC≡C)4Si (2-5) when treated with equivalent amounts of H3SiBr, H2SiBr2, HSiCl3, or SiCl4. respectively. The new silanes have been characterized by NMR data. The crystal structure of (Me3SiC≡C)4Si has been determined by single crystal X-ray diffraction. It shows the expected tetrahedral geometry at he central silicon atom with four linear SiC≡CSi linkages.
Synthese, Eigenschaften und Struktur neuer 1,1-Diphosphonsäuren / Synthesis, Properties and Structure of New 1,1-Diphosphonic Acids
Authors: Blum Helmut 
Published: March 2015

Abstract
The synthesis of 3-tert-alkyl-3-oxo-1-arninopropane-1,1-diphosphonic acids and of 3-tert-alkyl-3-oxo-prop-1-ene-1,1-diphosphonic acids as two new groups of metal complexing agents and their chemical properties are described. Evidence is given for their suggested structures. In addition, the first known example of a diphosphonic acid with a cyano group attached to the geminal carbon atom was prepared from 3-oxo-1-aminoalkane-1,1-diphosphonic acids and 3-terr-alkyl-3-oxo-1-hydroxypropane-1,1-diphosphonic acids from 3-oxo-1-aminopropane-1,1-diphosphonic acids.
Struktur und Schwingungsspektrum des Kaliumundecawolframats Kg6H4W11O38· 11H2O / Structure and Vibrational Spectrum of the Potassium Undecatungstate K6H4WnO38 -11 H2O
Authors: Lehmann Thomas , Fuchs Joachim 
Published: March 2015

Abstract
The title compound crystallizes in the triclinic space group P1̅ with lattice parameters a = 13.129 Å, b = 14.156 Å, c = 14.843 Å and α= 88.34°, β = 74.43°, γ = 70.86°. The polyanion evidently is the predominant species in pseudometatungstate phases the exact composition of which has not previously been determined.
Die Kristallstrukturen von Ph3PNPh, [Ph3PN(H)Ph][AuI2] und von 2,3-Bis(triphenylphosphoranimino)maleinsäure-N-methylimid / The Crystal Structures of Ph3PNPh, [Ph3PN(H)Ph][AuI2] and of 2,3-Bis(triphenylphosphoranimino)maleic Acid-N-methylimide
Authors: Böhm Eberhard , Dehnicke Kurt , Beck Johannes , Hiller Wolfgang , Strähle Joachim , Maurer Andreas , Fenske Dieter 
Published: March 2015

[Ph3PN(H)Ph][AuI2] (2) is formed by the reaction of AuI with N-Phenyl-iminotriphenylphosphorane, Ph3PNPh in a toluene suspension. 2,3-Bis(triphenylphosphinimino)maleic acid-N-methylimide (3) has been prepared by the Staudinger reaction of 2,3-bis(azido)maleic acid-N-methylimide with PPh3 in THF solution in the form of red crystals. Crystal structure determinations of three iminophosphoranes were carried out by X-ray methods.
Ph3PNPh (1): space group P21/c, Z = 4, 2176 independent observed reflexions, R = 0.057. Lattice dimensions (-30 °C): a = 1126.4, b = 1148.6, c = 1476.0 pm; β = 97.21°. The compound forms monomeric molecules with P=N = 160.2 pm and an PNC angle of 130.4°.
[Ph3PN(H)Ph][AuI2] (2): space group P1̄, Z = 2, 1780 independent observed reflexions, R = 0.057. Lattice dimensions (18 °C); a = 824.9, b = 1022, c = 1476.2 pm; α = 89.23°, β = 87.41°, γ = 85.65°. The compound consists of ions [Ph3PN(H)Ph]⊕ with P=N = 162.4 pm and PNC = 129.3°, and anions [AuI2]⊖ with Au-I = 261.9 and 259.3 pm, IAuI = 176.8°.
(Ph3P)2N2C4O2 (NMe) (3): space group P1̄, Z = 2, 4972 independent observed reflexions, R = 0.050. Lattice dimensions (-90 °C): a = 904.7, b = 993.8, c = 2017.4 pm; α = 101.55°, β = 96.39°, γ = 105.81°. The compound forms monomeric molecules with syn-conformation of the two NPPh3 groups. Bond lengths: P=N = 157.1; 155.3 pm, bond angles: PNC = 133°; 136°
Darstellung und Kristallstruktur von [(NH3)5Rh(H7O4)Rh(NH3)5](S2O6)2,5 · H2O (1). Ein gemischtes Aquopentamminrhodium(III)-hydroxopentamminrhodium(III)- dithionat mit einer neuartigen μ-H7O4-Struktureinheit / Preparation and Crystal Structure of [(NH3)5Rh(H7O4)Rh(NH3)5](S2O6)2,5 · H2O (1). A Mixed Aquopentaamminerhodium(III)-hydroxopentaamminerhodium(III) Dithionate with a Novel μ-H7O4 Structural Unit
Authors: Frank Walter , Stetzer Thomas , Heck Ludwig 
Published: March 2015

The title compound 1 can be obtained from an aqueous solution of aquopentaammine rhodium(III) dithionate and hydroxopentaammine rhodium(III) dithionate. The crystal structure has been determined from single crystal X-ray diffraction data and refined to R = 0.035 for 4390 unique reflections. Crystal data: monoclinic, space group P21/c, a = 1300.9(5) pm. b = 1472.3(6) pm. c = 1478.8(9) pm, β = 106.20(4)°, Z = 4.
In the crystal dinuclear rhodium cations with point group symmetry 1 (C1) are found. A central μ-H3O2-bridge is formed by strong hydrogen bonding between aquo and hydroxo ligands; this bridge is additionally coordinated by two molecules of water. The entire bridging system is therefore H7O4
-(H3O2
- · 2 H2O). O-O distances characterizing the strength of the three hydrogen bonds within this new kind of structural unit are O(H2O-Rh 1)-O(HO-Rh2): 248 pm. O(H2O-Rh 1)-O(H2Oa): 273 pm, O(HO-Rh2)-O(H2Ob): 287 pm. The hydrogen atoms involved in these bridges have been located. The small difference in the Rh 1-O(H2O) - (205.4(3) pm) and Rh2-O(OH)- (204.3(3) pm) distances indicates that the entire H7O4
-- moiety serves as a μ-bridging unit between Rh 1 and Rh 2