Volume 68, Issue 12

The magnesium-rich intermetallic phases RE 3 RuMg 7 (RE=Y, Nd, Dy, Ho) have been synthesized from the elements in sealed niobium ampoules and subsequently characterized by powder X-ray diffraction. The structure of the dysprosium compound was refined on the basis of single-crystal X-ray diffractometer data: Ti 6 Sn 5 type, P6 3 =mmc, a=1019.1(2), c=606.76(9) pm, wR2=0.0159, 439 F 2 values, 19 variables. The Mg3 site shows a small degree of Mg3=Dy mixing, leading to the composition Dy 3:03 RuMg 6:97 for the investigated crystal. The striking structural motifs in the Dy 3 RuMg 7 structure are rows of face-sharing Ru@Dy 6 octahedra and corner-sharing Mg2@Mg 8 Dy 4 icosahedra. The rows of octahedra form a hexagonal rod-packing, and each rod is enrolled by six rows of the condensed icosahedra. Temperature-dependent magnetic susceptibility measurements of Dy 3 RuMg 7 show Curie-Weiss behavior with an experimental magnetic moment of 10.66(1) µ B per Dy atom. Antiferromagnetic ordering is detected at T N =27.5(5) K. The 5 K isotherm shows a metamagnetic transition at a critical field of H C =40 kOe Graphical Abstract Magnesium-rich Intermetallics RE 3 RuMg 7 (RE=Y, Nd, Dy, Ho) – Rows of Condensed Ru@RE 6/2 Octahedra in Magnesium Matrices

X-Ray-pure samples of the solid solutions (Ce 1-x La x )RuSn were obtained up to x=0.5. Powder diffraction data show the CeRuSn-type superstructure up to x ≈ 0:3 and the CeCoAl-type subcell for higher lanthanum contents. The structure of a single crystal with x=0.5 was refined on the basis of single-crystal X-ray diffractometer data: CeCoAl type, C2=m, a=1160.8(2), b=477.6(1), c=511.6(1) pm, β = 102:97(2)°, wR=0.0510, 444 F 2 values, 20 variables. Magnetic investigations were performed for all samples up to a lanthanum content of x=0.4. No cooperative phenomena could be observed, and all samples show Curie-Weiss behavior above a certain temperature. The cerium valence is about 3.32(2) for all samples of the solid solution. Hence, La 3+ has to replace Ce 3+ as well as Ce 4+ in a particular quantity. The electrical resistivity measurements confirm the suppression of the magnetic ordering and the structural transition upon replacement of cerium by lanthanum. 119 Sn Mössbauer spectra of samples with x=0.2 and 0.5 are indicative of single tin sites with isomer shifts of δ =1.86(1)mm s-1 for x=0.2 and δ =1.88(1)mm s-1 for x=0.5. Both signals are subject to significant quadrupole splitting, a consequence of the low site symmetry. Results of XANES measurements are perfectly in line with the cerium valences determined by susceptibility measurements and yield a constant value of 3.16(1) for all investigated compounds Graphical Abstract The Solid Solutions (Ce 1-x La x )RuSn

Attempts to crystallize the sodium chromium alum, NaCr(SO4)2(H2O)12, from water=methanol solutions at temperatures around 281 K yielded crystals of the title compound instead. Their monoclinic structure can be described as a centered rectangular array of linear { 1 ∞ }[Na(SO 4 ) 2 ] 3- rods aligned parallel to [001] with vicinal rods held together by columns of isolated [Cr(H 2 O) 6 ] 3+ complexes. The structure forms channels parallel to [001] which are occupied by methanol and water molecules with atomic site occupancy factors of 1/5 and less. Various attempts to crystallize the compound or the sodium chromium alum from purely aqueous solutions remained unsuccessful Graphical Abstract In Search of the True Structure of the Sodium Chromium Alum II: Crystal Growth and Structure of the Double Salt NaCr(SO 4 ) 2 (H 2 O) 6 ·(CH 3 OH) 0.6(2) · (H 2 O) 1.5(5)

The new sulfido antimonates(III) (Rb=Cs) 3 SbS 3 were prepared from the alkali metal sulfides Rb 2 S=Cs 2 S 2 and elemental antimony and sulfur or Sb 2 S 3 at reaction temperatures of about 700 °C. The known isotypic potassium compound was similarily synthesized from the elements. The structures of the light-yellow crystals were refined using single-crystal X-ray data. Both compounds are isotypic to the respective Na salt forming the Na 3 AsS 3 structure type (cubic, space group P2 1 3, K/Rb/Cs: a = 947:21(7)=982:28(5)=1025:92(5) pm, Z = 4, R1 = 0:0159=0:0560=0:0582). The Ψ - tetrahedral SbS 3- 3 anions with Sb-S bond lengths of 242 pm are arranged in a cubic face centered packing, in which the three crystallographically different A + cations occupy the tetrahedral and octahedral voids, overall exhibiting a distorted octahedral sulfur coordination. The chemical bonding and the characteristics of the stereochemically active lone electron pair have been investigated by means of FP-LAPW band structure calculations. Needle-shaped crystals of the monohydrate of the antimony(V) salt Cs 3 SbS 4 · H 2 O were obtained from a suspension of Sb 2 O 3 , CsOH and elemental sulfur. Cs 3 SbS 4 · H2O crystallizes in a new structure type (monoclinic, space group P2 1 /c, a = 987:17(10), b = 994:83(7), c = 1600:46(14) pm, β = 126:895(8)°, Z = 4, R1 = 0:0234). As expected, the Sb-S distances (233.1 - 234.7 pm) in the nearly ideally tetrahedral anion SbS 3- 4 are considerably shorter than in the antimonates(III) but match the bond lengths in the anhydrous sulfido antimonate(V) Cs 3 SbS 4 . Due to their similar fcc-like anion packing and the stereochemically active lone electron pair of Sb in the antimonates(III), the whole series of compounds A 3 Sb III,V S 3/4 shows a uniform structure relation, which is elucidated using crystallographic group-subgroup relations Graphical Abstract Neue Sulfido-Antimonate der schweren Alkalimetalle: Synthese, Kristallstruktur und chemische Bindung von (K=Rb=Cs) 3 SbS 3 und Cs 3 SbS 4 · H 2 O / New Sulfido Antimonates of the Heavy Alkali Metals: Synthesis, Crystal Structure and Chemical Bonding of (K=Rb=Cs) 3 SbS 3 and Cs 3 SbS 4 · H 2 O

Several 3,6-disubstituted 1,2,4,5-tetrazines were synthesized by nucleophilic substitution using 3,6-bis-(3,5-dimethyl-pyrazol-1-yl)-1,2,4,5-tetrazine and 3,6-dichloro-1,2,4,5-tetrazine as electrophiles. All new compounds were characterized by 1 H NMR, 13 C NMR and vibrational spectroscopy, mass spectrometry and elemental analysis (C,H,N). For analysis of the thermostability, differential scanning calorimetry (DSC) was used. Especially, the symmetrically bis-3,5-diamino-1,2,4- triazolyl-substituted derivative shows a very high thermal stability up to 370 °C. Therefore its energetic properties were determined and compared with thoses of hexanitrostilbene (HNS). The crystal structures of 3,6-bishydrazino-1,2,4,5-tetrazine, 3,6-dichloro-1,2,4,5-tetrazine and 3-amino-6-(3,5- diamino-1,2,4-triazol-1-yl)-1,2,4,5-tetrazine dihydrate have been determined by low-temperature X-ray diffraction Graphical Abstract Thermally Stable 3,6-Disubstituted 1,2,4,5-Tetrazines

A tri(gold)boride of the formula B[AuP(o-Tol) 3 ] 3 (2) is generated in the reaction of the silylated phosphine borane Cy 3 PBH 2 SiMe 3 with the tri(gold)oxonium tetrafluoroborate [(o-Tol) 3 PAu] 3 O+ BF 4 - and isolated as its stable 1 : 1 complex with tricyclohexylphosphine: Cy 3 PB[AuP(o-Tol) 3 ] 3 . The composition of the product has been confirmed by elemental analyses and mass spectrometry. Solution NMR data of 2 indicate a molecular structure with C 3ν symmetry which has been confirmed by MP2 calculations for the model system H 3 PB(AuPH 3 ) 3 . The compound is a rare case of a trimetallated boride which is isolobal with the simple phosphineborane Cy 3 PBH 3 . With reagents bearing less bulky substituents (R3 = i Pr 3 , MePh 2 , Ph 3 ), the reactions proceed to salts with the tetra-aurated cations [Cy 3 PB(AuPR 3 ) 4 ] + Graphical Abstract Synthesis of a Tri(gold)boride Complex (Cy 3 P)B[AuP(o-Tol) 3 ] 3

The synthesis of a Zn(II) complex of bispicen, the tetradentate ligand N,N′-bis(2-pyridylmethyl)- ethylenediamine, of composition [Zn(bispicen)Cl(H 2 O)] 2 [ZnCl 4 ] is reported. Its crystal and molecular structure was determined by single-crystal X-ray diffraction methods. It crystallizes in the monoclinic space group C2=c with Z =4 molecules per unit cell. The Zn(II) cation in the [Zn(bispicen)Cl(H 2 O)] + complex is in a distorted octahedral environment, coordinated to a neutral bispicen molecule acting as a tetradentate ligand through its two amine nitrogen atoms, at cis positions, and its two pyridyl N atoms, at trans positions. The six-fold coordination is completed by a chloride ion and a water molecule. The tetrahedral [ZnCl 4 ] 2- counter-ion lies on a crystallographic twofold axis. The complex was further characterized by FTIR spectroscopy, and its vibrational behavior compared with that of the dihydrated tetrahydrochloride of free bispicen Graphical Abstract Synthesis and Characterization of a Zinc(II) Complex of Bispicen

A Cd(II) complex based on fluconazole and isophthalate ligands, {[Cd(HFlu)(IPA)(H 2 O)] · H 2 O} n (1), (HFlu=fluconazole; H 2 IPA=isophthalic acid) has been synthesized. Single-crystal X-ray analysis reveals that complex 1 has a 2D network structure including unusual triple hydrogen bonds between hydroxyl and triazolyl groups. The complex has also been characterized by IR, UV=Vis and fluorescence spectroscopy, elemental analysis, and thermogravimetry Graphical Abstract Synthesis, Structure and Properties of a 2D Cadmium(II) Coordination Polymer Based on Fluconazole and Isophthalate Ligands

Dark-green crystals of [Rb(12-crown-4) 2 ]I 5 were obtained by the reaction of stoichiometric amounts of RbI, I 2 and 12-crown-4 from an ethanol=methanol solution (monoclinic space group P2 1 =n with Z = 4, a = 8:9200(10), b = 24:069(2), c = 13:9950(10) Å and β = 91:984(9)°). The crystal structure contains one independent formula unit consisting of the polyiodide and the cation. The anionic part of the structure is an isolated, V-shaped pentaiodide I 5 - . The cation is a sandwich complex with two 12-crown-4-molecules surrounding the alkali metal atom Graphical Abstract Darstellung, strukturelle und spektroskopische Charakterisierung eines Pentaiodids [Rb(12-Krone-4) 2 ]I 5 / Preparation, Structural and Spectroscopic Characterization of a Pentaiodide [Rb(12-Crown-4) 2 ]I 5

1,2,5,6,9,10-Hexaalkoxyhexahelicenes 3 represent [3]star compounds with a helical core. A multistep synthetic concept for 3 is discussed, in which the final step 16→3 is a twofold oxidative photocyclization. The linearly conjugated compounds 16 contain stilbene and vinylnaphthalene units Graphical Abstract Preparation of 1,2,5,6,9,10-Hexaalkoxyhexahelicenes

The planned model calculations of normal modes of pseudo-trigonal-bipyramidal LaCp 3 (NCCH 3 ) 2 (Cp = η5-C 5 H 5 -) (1) adopting density functional theory (DFT), and using the molecular structure as suggested by X-ray investigations, did not converge. Alternatively, DFT calculations assuming molecular C 3h symmetry were performed. Unfortunately, these calculations did not reproduce the experimentally derived frequencies of the skeletal modes very well, including a wrong energetic sequence of the four previously unambiguously assigned (close lying) Raman-active ν(La-Cp) skeletal modes. The same presumably also holds for DFT calculations made for LaCp 3 · NCCH 3 (2) and base-free LaCp3 (3), assuming molecular C 3 and C 3h symmetry, respectively. In order to check whether the calculated incorrect sequence is produced by the five-membered Cp rings, a DFT calculation also has been performed for the hypothetical model complex [La(η 6 -C 6 H 6 ) 3 ] 3+ (4) of D3 symmetry. A closer examination of the vibronic sidebands of the hypersensitive absorption transition 4 I 9/2 → 4 G 5/2 of [LaCp 3 (NCCH 3 ) 2 :Nd 3+ ] (5) showed that first of all, totally symmetric intraligand and not skeletal vibrations are coupling as it was the case for [LaCp 3 (NCCH 3 ) 2 :Ln 3+ ] (Ln = Pr, Sm). Applying this result to the vibronic sidebands of some purely electronic crystal field (CF) transitions, which are hampered by strong binary combination vibrations, the energies of these CF levels could be determined. The CF state 1Γ8 of the ground multiplet 4 I 9/2 of [LaCp 3 (NCCH 3 ) 2 :Nd 3+ ], which previously could not be detected by absorption measurements, could be derived from the luminescence transition 4 F 3/2 → 4 I 9/2 . Considering these additional assignments, the goodness of the fit increased from 32.3 to 29.9 cm -1 for 61 assignments Graphical Abstract Zur Elektronenstruktur metallorganischer Komplexe der ƒ -Elemente, 81. Berechnung der Normalschwingungen von La(η 5 -C 5 H 5 ) 3 (NCCH 3 ) 2 auf der Basis der Dichtefunktionaltheorie sowie vibronische Kopplungen und Auffindung weiterer rein elektronischer Absorptions- und Lumineszenzüberg¨ange bei [La(η 5 -C 5 H 5 ) 3 (NCCH 3 ) 2 :Nd 3+ ] / Electronic Structures of Organometallic Complexes of f Elements, 81. Calculation of the Normal Modes of La(η 5 -C 5 H 5 ) 3 (NCCH 3 ) 2 on the Basis of Density Functional Theory as well as Vibronic Couplings and Identification of Further Purely Electronic Absorption and Luminescence Transitions of [La(η 5 -C 5 H 5 ) 3 (NCCH 3 ) 2 :Nd 3+ ]

The carbonyl complex [Os II (NH 3 ) 5 (CO)] 2+ undergoes a photolysis in aqueous solution which yields [Os VI (NH 3 ) 4 N] 3+ (Φ=10 -3 at λ irr =255 nm) and methanol. This photoreduction of CO to CH 3 OH represents a novel type of photoreactivity of metal carbonyl complexes and could be utilized for an artificial photosynthesis Graphical Abstract Photoreduction of CO to Methanol. The Photolysis of Aqueous Solutions of [Os(NH 3 ) 5 (CO)] 2+