Phosphaniminato-Komplexe Seltener Erden. Synthese und Kristallstrukturen von [M2(C5H5)3(NPPh3)3] · 3 C7H8 mit M = Y,Dy und Er. Magnetische Eigenschaften von [Dy2(C5H5)3(NPPh3)3] · 3 C7H8

Phosphoraneiminato Complexes of Rare Earths Elements. Syntheses and Crystal Structures of [M₂(C₅H₅)₃(NPPh₃)₃] · 3 C₇H₈ mit M = Y, Dy, and Er. Magnetic Properties of [Dy₂(C₅H₅)₃(NPPh₃)₃] · 3 C₇H₈ The title compounds have been prepared by reactions of the cyclopentadienidchlorides [M(C₅H₅)₂Cl]₂ with LiNPPh₃ in boiling toluene, and they were characterized by crystal structure determinations. All three compounds crystallize isotypicly with one another within the orthorhombic space group Pbca with Z = 8. Two of the three phosphoraneiminato groups link the metal atoms via μ₂-N atoms to almost planar M₂N₂ four-membered rings. The third NPPh₃^– group is terminally bonded. The magnetic susceptibility of [Dy₂(C₅H₅)₃(NPPh₃)₃] · 3 C₇H₈ has been determined (SQUID magnetometer) in the temperature range 1.7 K–300 K at magnetic fields between 0.01 T and 5 T. Calculations based on a cubic ligand field model lead to a satisfactory simulation with reasonable ligand field parameters. The inclusion of isotropic intramolecular exchange interactions in the model does not improve the fit, so that in the framework of the applied model no hints to a spin-spin coupling within the dinuclear units are obtained.     

Darstellung und Kristallstrukturen von Silber(I)-Gemischtligandkomplexen mit Bibenzimidazol und Triphenylphosphan: [Ag(PPh3)2(bbimH2)](COOCH3) · 2 CH2Cl2 und [{Ag(PPh3)2}2(μ-bbim)] · 4 CH2Cl2

Preparation and Crystal Structures of Silver(I) Mixed Ligand Complexes with Bibenzimidazole and Triphenylphosphane: [Ag(PPh₃)₂(bbimH₂)](COOCH₃) · 2 CH₂Cl₂ and [{Ag(PPh₃)₂}₂(μ-bbim)] · 4 CH₂Cl₂ The title compounds are obtained from silver acetate, 2,2′-bibenzimidazole and PPh₃. They are characterized by their IR, ¹H-NMR, ³¹P-NMR spectra and crystal structure determinations. [Ag(PPh₃)₂(bbimH₂)](COOCH₃) · 2 CH₂Cl₂: Reaction in CH₂Cl₂. Space group C2/c, Z = 4, 3129 observed unique reflections, R = 0.033. Lattice parameters at 203 K: a = 1450.8; b = 1556.2; c = 2316.4 pm; β = 99.69°. The crystal structure is built up by monomeric molecules with distorted tetrahedral coordination of the silver atom (AgP₂N₂) and bibenzimidazole as a bidentate ligand. The acetate ion is linked to the NH-groups of the bibenzimidazole by hydrogen bonds. [{Ag(PPh₃)₂}₂(μ-bbim)] · 4 CH₂Cl₂: Reaction in fused PPh₃ at 180 °C. Space group P 1, Z = 1. 9227 observed unique reflections, R = 0.051. Lattice parameters at 203 K: a = 1276.5; b = 1352.1; c = 1408.1 pm; α = 96.97; β = 115.87; γ = 96.84°. The crystal structure is built up by centrosymmetric molecules with distorted tetrahedral coordination of the silver atoms (AgN₂P₂) and bibenzimidazolate(2–) as tetradentate bridging ligand.     

Zweikernige Antimon(V)-Komplexe mit Diphenylphosphato-Brückenliganden

Binuclear Antimony(V) Complexes with Bridging Diphenylphosphato Ligands The binuclear antimony(V) complexes Cl₃Sb(O)[(C₆H₅O)₂PO₂]₂SbCl₃ ( 1 ), Cl₃Sb(O)[(C₆H₅O)₂PO₂](OCH₃)SbCl₃ ( 2 ), Cl₃Sb(O)[(C₆H₅O)₂PO₂](OH)SbCl₃ ( 3 ) and Cl₄Sb[(C₆H₅O)₂PO₂]₂SbCl₄ ( 4 ) are prepared by reaction of diphenylphosphoric acid with antimony(V) chloride, water and methanol in different molar ratios. The progress of the reactions was controlled by the ³¹P-NMR signals. 1 crystallizes triclinic in the space group P1 with a = 918.8, b = 1312.9, c = 1395.8 pm, α = 91.91, β = 101.36, γ = 95.90° and Z = 2. 2 to 4 crystallize in monoclinic space groups: 2 : C2/c, a = 2753.4, b = 1156.1, c = 1476.7 pm, β = 98.01° and Z = 8; 3 : P2₁/c, a = 1234.8, b = 1471.8, c = 1263.4 pm, β = 107.15° and Z = 4; 4 : P2₁/n, a = 1943.8, b = 940.8, c = 2015.6 pm, β = 109.87° and Z = 4 resp. The NMR spectra are discussed and some IR data are communicated.     

Zur Reaktion von tert-Butyl-phosphaalkin mit Molybdänkomplexen

Reaction of tert -Butyl-phosphaalkyne with Molybdenum Complexes The reaction of tBuC≡P with [(CH₃CN)₃Mo(CO)₃] leads to the complex [Mo(CO)₄〈Mo(CO)₂(η⁴-P₃CtBu){η⁴-P₂(CtBu)₂}〉] 1 as well as to the alkyne complexes [Mo(CO)₄〈{P₃(CtBu)₂}{Mo(CO)₂(CtBu)}{η³-P₂(CtBu)₂}〉] 2 and [Mo(CtBu){η⁴-P₂(CtBu)₂(CO)}{η⁵-P₃(CtBu)₂}] 3 . All compounds are characterized by X-ray structural analysis, by NMR- and IR spectroscopy and by mass spectrometry. In complex 1 a 1,3-diphosphacyclobutadiene and a 1,2,4-triphosphacyclobutadiene are connected by two molybdenum carbonyl centres. In 2 a 1,3-diphosphacyclobutadiene is π- and a novel 1,2,4-triphospholyl ligand is σ-bonded at two Mo centres. A characteristic feature of 3 besides a π co-ordinated 1,2,4-triphospholyl ligand is a 3,4-diphosphacyclopentadienone as ligand, formed via CO insertion during the cyclodimerisation of two phosphaalkynes.     

Synthese und Kristallstrukturen der Zink-Amido-Komplexe [Zn(NPh2)2]2 und [Zn(NPh2)2(THF)2]

Synthesis and Crystal Structures of the Zinc Amido Complexes [Zn(NPh₂)₂]₂ and [Zn(NPh₂)₂(THF)₂] Zinc diphenylamide is prepared from Zn[N(SiMe₃)₂]₂ and diphenylamine by transamination reaction. The compound is characterized by a crystal structure analysis. According to it [Zn(NPh₂)₂]₂ forms centrosymmetric dimeric molecules with Zn–N distances of 185.9 pm for the terminally bonded NPh₂^– ligand and Zn–N distances of 204.0 and 202.6 pm in the four-membered ring. From tetrahydrofuran solutions [Zn(NPh₂)₂(THF)₂] crystallizes as monomeric molecular complex with Zn–N bond lengths of 192.2 pm in average.     

Synthese,Struktur und Photolyse von Isocyanatokomplexen des Rheniums

Synthesis, Structure, and Photolysis of Isocyanato Complexes of Rhenium The Re^III isocyanato complex Re(NCO)₃(PMe₂Ph)₃ yields from the reaction of ReCl₃(PMe₂Ph)₃ with an excess of NaOCN in EtOH. It crystallizes in the triclinic space group P 1 with a = 991.8(6), b = 1180.7(6), c = 1348.8(5) pm, α = 89.85(1)°, β = 94.12(1), γ = 111.56(1)°, Z = 2. In the mononuclear complex with an octahedral coordination of the Re atoms the phosphine and isocyanato ligands exhibit a meridional arrangement. By using a deficient amount of NaOCN the mono isocyanato complex Re(NCO)Cl₂(PMe₂Ph)₃ is formed, and part of the educt is transformed to its isomer [(Me₂PhP)₃Re(μ-Cl)₃Re(PMe₂Ph)₃]Cl₃. The mono isocyanato complex forms monoclinic crystals with the space group P2₁/n and a = 1467.5(7), b = 1310.6(7), c = 1603.2(8) pm, β = 112.08(1)°, Z = 4. The isocyanato ligand is in trans position to a Cl atom, and the phosphine ligands are coordinated in a meridional arrangement. [(Me₂PhP)₃Re(μ-Cl)₃Re(PMe₂Ph)₃]Cl₃ · 2 EtOH crystallizes in the hexagonal space group P6₃/m with a = 1332.6(2), c = 2300.1(7) pm, Z = 2. The dinuclear complex cation occupies with its center a special position with the symmetry C_3h. Photolysis of Re(NCO)Cl₂(PMe₂Ph)₃ results in the cleavage of the isocyanato ligand with release of CO and formation of the nitrido complex ReNCl₂(PMe₂Ph)₃. The reaction of ReNCl₂(PMe₂Ph)₃ with NaOCN affords the complex ReN(NCO)₂(PMe₂Ph)₃. It crystallizes in the space group P2₁/n with a = 943.0(3), b = 2635.2(4), c = 1212.6(5) pm, β = 109.88(1)°, Z = 4. In this nitrido complex, like in the educt, the phosphine ligands form a meridional arrangement. The nitrido ligand is in trans position to an isocyanato group. The distance Re≡N is 165.9(6) pm.     

Amidoliganden zum Aufbau von mehrkernigen Lanthanoidkomplexen

Amido Ligands for the Synthesis of Polynuclear Lanthanoid Complexes By 1 : 1 reaction of LnBr₃ with NaNHPh in THF the Rare-Earth Complexes [Ln₂Br₄(μ₂-NHPh)₂(thf)₅] (Ln = Sm ( 1 ), Ln = Gd ( 2 )) with two bridging anilido ligands are obtained. In the system LnBr₃/NaNHPh/(Me₂SiO)₃ the tetranuclear compounds [Ln₄(μ₄-O)(NHPh)₃(OSiMe₂NPh)₆Na₅(thf)₇] · THF (Ln = Gd ( 3 ), Ln = Yb ( 4 )) can be built up. They have a central μ₄-oxygene atom in the Ln₄-tetrahedron. It has an oxa-dimethylsilyl-N-phenylamido ligand over all edges and an anilido ligand on three vertexes. By this reaction small amount of [Na₄(thf)₆Yb₂(OSiMe₂NPhSiMe₂O)₂(OSiMe₂NPh)₂(NHPh)₂] ( 5 ) with a O- and N-bridged Yb–Na polyhedron and N-phenyl-bis(dimethylsilanolato)-ligands coordinating μ₂-η² with its oxygen atoms are obtained. Reaction of Lanthanideshalides with LiNH^tBu leads to dimeric complexes. The formation of bridging oxasilylamido ligands is also observed. The compound [Li₂Ln(OSiMe₂N^tBu)₂(HN^tBu)(thf)]₂ (Ln=Sm ( 6 ), Gd ( 7 ) and Yb ( 8 )) contains now an O- and N-bridged Ln–Li polyhedron. (Crystal Data of 1–8 see ‘‘Inhaltsverzeichnis”︁”︁).     

N,N-Dimethylcarbamato-Komplexe von Kupfer und Zink

N,N -Dimethylcarbamato Complexes of Copper and Zinc Reactions of the 1 : 1 adduct of dimethylamine and carbon dioxide (dimcarb) with metallic copper and zinc, respectively, are reported. Dimcarb gives with copper in the presence of oxygen the N,N-dimethylcarbamato copper(II) complex [Cu(O₂CNMe₂)₂(HNMe₂)₂] ( 1 ). Zinc spontaneously dissolves in a dimcarb-acetonitrile mixture under generation of hydrogen and giving (H₂NMe₂)[Zn₂(O₂CNMe₂)₅] · MeCN ( 3 ). The rate of this reaction is strongly depending on the purity of the metal, high purity zinc doesn't react. But 3 can be prepared from it by electrosynthesis. The crystal structures of 1 and 3 were determined by X-ray analysis. In 1 the copper atom has a distorted octahedral coordination sphere in which the two carbamate ligands are chelating. In the homoleptic complex anion of 3 two zinc atoms are bridged by three carbamate ligands whereas the other two carbamate ligands are coordinated monodentately.     

Synthese und Kristallstrukturen der Nitrido‐Chloro‐Molybdate [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 und [Li(12‐Krone‐4)(NMoCl4)]2 · 2 CH2Cl2

Syntheses and Crystal Structures of the Nitrido‐chloro‐molybdates [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ and [Li(12‐Crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ Both the title compounds as well as [Li(12‐crown‐4)₂]⁺MoNCl₄^– were made from MoNCl₃ and the chlorides MgCl₂ and LiCl, respectively, in dichloromethane suspensions in the presence of tetrahydrofuran and 12‐crown‐4, respectively. They form orange‐red moisture‐sensitive crystals, which were characterized by their IR spectra and partly by crystal structure analyses. [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ ( 1 ): space group C2/m, Z = 2, lattice dimensions at –50 °C: a = 1736.6(1), b = 1194.8(1), c = 1293.5(2) pm; β = 90.87(1)°; R₁ = 0.037. In 1 the magnesium ion is coordinated octahedrally by the oxygen atoms of the four THF molecules and in trans‐position by the nitrogen atoms of the two [N≡MoCl₄(THF)]^– ions. [Li(12‐crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ ( 2 ): space group P 1, Z = 1, lattice dimensions at –70 °C: a = 930.4(1), b = 957.9(1), c = 1264.6(1) pm; α = 68.91(1)°, β = 81.38(1)°, γ = 63.84(1)°; R₁ = 0.0643. 2 forms a centrosymmetric ion ensemble in the dimeric cation of which, i. e. [Li(12‐crown‐4)]₂²⁺, the lithium ions on the one hand are connected to the four oxygen atoms each of the crown ether molecules in a way not yet known; and in addition, each of the lithium ions enters into a intermolecular Li–O bond with neighboring crown ether molecules under formation of a Li₂O₂ four‐membered ring. The two N≡MoCl₄^– counterions are loosely coordinated to one oxygen atom each of the crown ether molecules with Mo–O distances of 320.2 pm.     

The Influence of the Ligands Cp*(η5‐C5Me5) and Cp(η5‐C5H5) on the Stability and Reactivity of Titanocene and Zirconocene Complexes: Reactions of the Bis(trimethylsilyl)acetylene Permethylmetallocene Complexes (η5‐C5Me5)2M(η2‐Me3SiC2SiMe3), M = Ti,Zr, with H2O and CO2

The reactions of the bis(trimethylsilyl)acetylene permethylmetallocene complexes CpM(η²‐Me₃SiC₂SiMe₃) (M = Ti ( 1 ), M = Zr ( 2 )) with H₂O and CO₂ were studied and compared to those of the corresponding metallocene complexes Cp₂M(L)(η²‐Me₃SiC₂SiMe₃) (M = Ti ( 3 ), L = – ; M = Zr, L = THF ( 4 )) to understand the influence of the ligands Cp(η⁵‐C₅H₅) and Cp*(η⁵‐C₅Me₅) as well as the metals titanium and zirconium on the reaction pathways and the obtained products. In the reaction of the permethyltitanocene complex 1 with water the dihydroxy complex CpTi(OH)₂ ( 5 ) was formed. This product differs from the well‐known titanoxane Cp₂TiOTiCp₂ which was obtained by the reaction of the corresponding titanocene complex 3 with water. The reaction of the permethylzirconocene complex 2 with water gives the mononuclear alkenyl zirconocene hydroxide 6 . An analogous product was assumed as the first step in the reaction of the corresponding zirconocene complex 4 with water which ends up in a dinuclear zirconoxane. In the conversion of the permethylzirconocene complex 2 with carbon dioxide the mononuclear insertion product 7 was formed by coupling of carbon dioxide and the acetylene. In contrast, the corresponding zirconocene complex 4 affords, by an analogous reaction, a dinuclear complex. In additional experiments the known complex CpZr(η²‐PhC₂SiMe₃) ( 8 ) was prepared, starting from CpZrCl₂ and Mg in the presence of PhC≡CSiMe₃. This complex reacts with carbon dioxide resulting in a mixture of the regioisomeric zirconafuranones 9 a and 9 b . From these in the complex 9 a , having the SiMe₃ group in β‐position to the metal, the Zr–C bond was quickly hydrolyzed by water to give the complex CpZr(OH)OC(=O)–C(SiMe₃)=CHPh ( 10 a ) compared to complex ( 9 b ) which gives slowly the complex CpZr(OH)OC(=O)–CPh=CH(SiMe₃) ( 10 b ).