Darstellung von μ-Hydrido-μ-diphenylphosphido-bis(tetracarbonylrhenium) · 1/2 Xylol und Molekülstruktur des Derivates Re2(CO)6(PPh3)2(μ-H)(μ-PPh2) (Ph = C6H5)

Preparation of μ-Hydrido-μ-diphenylphosphido-bis(tetracarbonylrhenium) · 1/2 Xylene and Molecular Structure of the Derivative Re₂(CO)₆(PPh₃)₂(μ-H)(μ-PPh₂) (Ph = C₆H₅) The reaction of dirhenium decacarbonyl with diphenylphosphine in xylene solution gave at 190–200°C in a glas tube crystals of Re₂(CO)₈(μ-H)(μ-PPh₂) · 1/2 C₈H₁₀. The obtained adduct was reacted in the same solvent with an excess of triphenylphosphine to the derivative Re₂(CO)₆(PPh₃)₂(μ-H)(μ-PPh₂). Both diamagnetic dirhenium compounds with μ-H atom and μ-PPh₂ group were characterized by ¹H and ³¹P spectroscopic measurements. The molecular structure of the derivative was acertained by a single crystal X-ray analysis. Its result showed a three-membered Re₂(μ-P) ring as central molecular fragment. At these Re central atoms were attached two PPh₃ ligands in an unprefered cis-arrangement due to sterical reasons. A thermodynamic transinfluence of the (μ-P)? Re bond favoured the found positions of the PPh₃ ligands.     

Synthese und Kristallstrukturen der Phosphanimin-Komplexe [Cu(μ-HNPEt3)]4(O3S–CF3)4 und [Pt2Me6(μ-I)2(μ-HNPMe3)]

Synthesis and Crystal Structures of the Phosphaneimine Complexes [Cu(μ-HNPEt₃)]₄(O₃S–CF₃)₄ and [Pt₂Me₆(μ-I)₂(μ-HNPMe₃)] The title compounds have been prepared by the reaction of copper(I)triflate with [NiBr(NPEt₃)]₄ in CH₂Cl₂ suspension in the presence of water, and by the reaction of [PtMe₃I]₄ with Me₃SiNPMe₃ in boiling toluene in the presence of cesium fluoride, respectively. According to the crystal structure determinations the cation of the copper complex forms tetrameric units [Cu(HNPEt₃)]₄⁴⁺ with S₄ symmetry with Cu–N bond lengths of 191.6 and 192.1 pm. In the platinum complex the platinum atoms are linked by two μ-I bridging atoms as well as by the μ-N atom of the HNPMe₃ ligand with Pt–N bond lengths of 228.1 and 229.5 pm.     

Synthese und Molekülstruktur von [Li(THF)4][{(CO)4Mo}2(μ-PPh2)(μ-PPh2PPh2)]: Die erste Verbindung mit einem 1,3-Dimetalla-cyclopentaphosphan-Gerüst

Synthesis and Molecular Structure of [Li(THF)₄][{(CO)₄Mo}₂(μ-PPh₂)(μ-PPh₂PPh₂)]: The First Compound with an 1,3-Dimetalla-cyclopentaphosphane Ring [Mo(CO)₄(NBD)] (NBD = norbornadiene) reacts with LiPPh₂ and PPh₂PPh₂ in THF at –80 °C to give [Li(THF)₄][{(CO)₄Mo}₂(μ-PPh₂)(μ-PPh₂PPh₂)] ( 1 ). 1 exhibits an A₂X coupling pattern in the ³¹P NMR spectrum. A crystal structure determination showed the presence of bridging phosphanido (PPh₂) and diphosphane ligands (PPh₂PPh₂). The central Mo₂P₃ five-membered ring adopts a half-chair conformation and thus resembles an inorganic cyclopentane.     

“Cage‐like” Carboxyl Bridged Octaphenyltetraantimony Compounds (SbPh2)4(μ‐O)4(μ‐OH)2(μ‐O2CR)2: Synthesis and Structural Characterization

The metal‐directed self‐assembly of biphenylantimony trichloride and homocarboxylic acids LH [L = 2‐CHO‐C₆H₄COO^– ( 1 ), 2, 3‐2F‐C₆H₄COO^– ( 2 ), 4‐CF₃–C₆H₄COO^– ( 3 )] provided three novel tetranuclear organoantimony(V) complexes, which were characterized by elemental analysis, FT‐IR, ¹H, and ¹³C NMR spectroscopy as well as melting point, and X‐ray single crystal analysis. In the molecular structure, four hexacoordinate antimony atoms are linked into a [Sb₂(μ‐O)₂]₂(μ‐O)₂ “cage” architecture by oxo‐bridges which are terminally bridged by two carboxyl groups.