The First Molybdenum Oxo‐iodide Cluster – [Mo4OI12]2–

Reaction of Mo(CO)₆ with Bu₄NI and I₂ in diglyme yielded a new butterfly Mo^III cluster [Mo₄OI₁₂]^2–. The structure of tetraphenylphosphonium salt was determined by X‐ray single crystal diffraction. Ph₄P⁺ and Bu₄N⁺ salts were further characterized by elemental analysis, mass spectrometry, energy‐dispersive X‐ray (EDX), IR, Raman, and UV/Vis spectroscopy and CVA studies. The cluster anion has a butterfly array of molybdenum atoms and can be represented as [Mo₄(μ₄‐O)(μ₃‐I)₂(μ₂‐I₄)I₆]^2–.     

Site‐Specific Substitution Preferences in the Solid Solutions Li12Si7–xGex,Li12–yNaySi7, Na7LiSi8–zGez,and Li3NaSi6–vGev

The mixed silicide‐germanides Li₁₂Si_7–xGe_x, Na₇LiSi_8–zGe_z, and Li₃NaSi_6–vGe_v which could serve as potential precursors for Si_1–xGe_x materials were synthesized and characterized by X‐ray diffraction methods. The full solid solution series Li₁₂Si_7–xGe_x (0 ≤ x ≤ 7) is easily accessible from the elements and features preferential occupation of the more negatively charged crystallographic tetrel positions by Ge, which is the more electronegative element. In case of Na₇LiSi_8–zGe_z a broad solid solution range of 1.3 ≤ x ≤ 8 is available but the ternary silicide Na₇LiSi₈ could not be obtained by the tested methods of synthesis. The solubility of Ge in Li₃NaSi_6–vGe_v is highly limited to a maximum of v ≈ 0.5, and again the formally more negatively charged tetrel positions are preferred by Ge. Additionally, the two crystallographic Li positions in Li₁₂Si₇ with unusually large displacement parameters can be partially substituted by Na in Li_12–yNa_ySi₇ with 0 ≤ y ≤ 0.6. The statistical mixing of Li and Na in this solid solution contrasts the typical ordering of Li and Na in most ternary tetrelides.     

Na3RuD7 – Synthese und Struktur

Na₃RuD₇ – Synthesis and Structure Na₃RuD₇ was synthesized by the reaction of sodium deuteride with ruthenium powder under a hydrogen pressure of 6000 bar at 900 K. X‐ray investigations on powdered samples and elastic neutron diffraction experiments led to the atomic arrangement (space group: P4₂/mnm), which is characterized by isolated [RuD₇]‐anions. The coordination polyhedron formed by the seven deuterium ligands can be described as a distorted pentagonal bipyramide.     

Cyclic Tribismuthide as a Piano Stool Complex Ligand – Synthesis and Crystal Structure of (η3‐Bi3)M(CO)33– (M = Cr,Mo)

The reactions between K₅Bi₄, [(C₆H₆)Cr(CO)₃] or [(C₇H₈)Mo(CO)₃], and [2.2.2]crypt in liquid ammonia yielded the compounds [K([2.2.2]crypt)]₃(η³‐Bi₃)M(CO)₃ · 10NH₃ (M = Cr, Mo), which crystallize isostructurally in P2₁/n. Both contain an 18 valence electron piano‐stool complex with a η³‐coordinated Bi₃‐ring ligand. The Bi–Bi distances range from 2.9560(5) to 2.9867(3) Å and are slightly shorter than known Bi–Bi single bonds but longer than Bi–Bi double bonds. The newly found compounds complete the family of similar complexes with E₃‐ring ligands (E = P‐Bi).     

Ru–η6‐benzene–phosphine complex‐catalyzed transfer hydrogenation of ketones

Three Ru–η⁶‐benzene–phosphine complexes bearing tri‐(p‐methoxyphenyl)phosphine, triphenylphosphine and tri‐(p‐trifluoromethylphenyl)phosphine were synthesized and characterized by ³¹P{¹H} NMR, ¹H NMR, ¹³C{¹H} NMR and elemental analyses. Complex 1 was further identified by X‐ray crystallography. These complexes exhibit good to excellent activities for the transfer hydrogenation of ketones in refluxing 2‐propanol, and the highest turnover frequency (TOF) is up to 5940 h⁻¹. The effect of electronic factors of these complexes on the transfer hydrogenation of ketones reveals that the catalytic activity is promoted by electron‐donating phosphine and the catalyst stability is improved by electron‐withdrawing phosphine. Copyright © 2011 John Wiley & Sons, Ltd.     

Spectroscopical UV–Vis implications of an intramolecular η2–Mg coordination in bacteriochlorophyll–a from the Fenna–Matthews–Olson complex

Chlorophylls and their related compounds prominently feature a Mg²⁺ ion in the center of a porphyrine, with an intermolecular fifth coordination usually observed to place the ion out of the macrocyclic plane. Herein, we assess the role of a potential intramolecular η²–(C = C)Mg interaction and compare it to the intermolecular coordination from the Hystidine groupt to Mg²⁺ for Bacterichlorophyll–a (Bchl–a), the main photosynthetic pigment in the Fenna–Matthews–Olson complex present in green and purple bacteria. The influence of this fifth coordination on the UV‐Vis spectroscopy (CAM‐B3LYP/cc‐pVDZ), and the concomitant change in geometry around Mg in Bchl–a from planar to pyramidal is assessed by the quantum theory of atoms in molecules based non–covalent interactions scheme and through energetic analysis via natural bond orbital population methods at the M06‐2X/cc‐pVDZ and compared to the reference multi–hapto compound, magnesocene, Cp₂Mg.     

[Mo2(O2C–CH3)4 · 1/2 {(CH2)6N4} · 1/2 CH2Cl2] – ein Donor‐Akzeptor‐Komplex mit supramolekularer Struktur

[Mo₂(O₂C–CH₃)₄ · ¹/₂ {(CH₂)₆N₄} · ¹/₂ CH₂Cl₂] – a Donor‐Acceptor Complex with Supramolecular Structure Yellow single crystals of [Mo₂(O₂C–CH₃)₄ · ¹/₂ {(CH₂)₆N₄} · ¹/₂ CH₂Cl₂] ( 1 ) have been obtained by the reaction of the silylated phosphaneimine Me₃SiNPEt₃ with [Mo₂(O₂C–CH₃)₄] in dichloromethane solution. 1 forms a three‐dimensional network with linear N–Mo:Mo–N and tetrahedral (CH₂)₆N₄Mo₄ moieties, which is topologically related with the PtS type. Space group P4₂/nnm, Z = 4, lattice dimensions at –70 °C: a = b = 1121.7(1), c = 1395.0(3) pm, R₁ = 0.0413.