A novel closo-type metallaundecaborane, [1,1-(PPh3)2-2,5-(OEt)2-1-RuB10H8], and its relationship to the ‘isocloso’ series of metallaborane clusters

The new ruthenaundecaborane [(PPh₃)₂RuB₁₀H₈ (OEt)₂] may be considered as an eleven-vertex member of a previously unrecognised series of metallaboranes which are formally derived by the single capping of an arachno-type (rather than a nido-type) cluster geometry with a metal centre which can be thought of as contributing four orbitals to the cluster bonding schemes.     

Formation and Structure of an Anionic Ruthenaborane Compound:[Et4N][(PPh3)2ClRuB12H12]

在研究RuCl2(PPh3)3 和 closo-B10H102- 在乙醇中的反应时,意外分离得到一个阴离子型的钌硼烷化合物[Et4N][(PPh3)2ClRuB12H12], 并且经过红外光谱和单晶X射线衍射分析确证. 在其结构中,闭式B12H122-配体与Ru(II)中心通过三个B-H-Ru三中心-二电子键结合. 分析原因应是在通过文献方法制备闭式B10H102-时的少量副产物闭式B12H122-在反应体系中与RuCl2(PPh3)3反应而生成了标题化合物. 根据硼烷簇合物的电子计数规则, 标题化合物也可以看成是含有2n (n为簇顶点数)个骨架电子的pileo型簇合物, 具有加帽(capped)的闭式多面体骨架构型. 这是第一个阴离子型的含有闭式B12H122- 的钌化合物.     

Preparation and properties of dinitrogen complexes of molybdenum and tungsten with trimethylphosphine as coligand : III. Synthesis and properties of cis-[W(N2)2(PMe3)4], trans-[W(C2H4)2(PMe3)4] and [M(N2)(PMe3)5] (M = Mo,W). The crystal and molecular structure of [Mo(N2)(PMe3)5]

The reduction of [WCl₄(PMe₃)₃] with dispersed sodium, under dinitrogen, gives cis-[W(N₂)₂(PMe₃)₄], while under ethylene trans-[W(C₂H₄)₂(PMe₃)₄] is obtained. The ethylene complex can also be prepared by displacement of the dinitrogen molecules in cis-[W(N₂)₂(PMe₃)₄] by ethylene at room temperature and pressure. Interaction of cis-[M(N₂)₂(PMe₃)₄] complexes (M = Mo, W), with PMe₃, under helium or argon, yields [M(N₂)(PMe₃)₅]. The molybdenum complex crystallizes in the orthorhombic space group Pnma, with a 22.063(6), b 12.106(4), c 9.745(4) Å. The Mo—P distance trans to the dinitrogen ligand (2.483(7) Å) is slightly longer than the average of the other four Mo—P bonds (2.460(5) Å).     

Synthesis of (2S,3S)-[3-(2)H1]-4-methyleneglutamic acid and (2S,3R)-[2,3-(2)H2]-4-methyleneglutamic acid

(2S,3S)-[3-(2)H1]-4-Methyleneglutamic acid 1a and (2S,3R)-[2,3-(2)H2]-4-methyleneglutamic acid 1b have been synthesised for use in biosynthetic and metabolic studies.     

Syntheses and crystal structures of the closo-borate M[B8H9] (M = [PPh4]+ and [N(n-Bu4)]+)

Protonation of M(2)[B(8)H(8)] with HCl or NEt(3)·HCl resulted in M[B(8)H(9)] (M = [PPh(4)](+) or [N(n-Bu(4))](+)). The monoanion was isolated and characterized by (1)H, (1)H{(11)B}, (11)B, and (11)B{(1)H} NMR spectroscopy. The "protonated" form [B(8)H(9)](-) showed a dynamic behavior in solution, which was analyzed by NMR spectroscopy and compared with theoretical calculations. The structures of [B(8)H(9)](-) as well as [B(8)H(8)](2-) were determined by single-crystal X-ray diffraction.     

Neue Phosphido-verbrückte Mehrkernkomplexe des Ag,Cd und Zn Die Kristallstrukturen von [Ag4(PPh2)4(PMe3)4], [Ag6(PPh2)6(PtBu3)2] und [M4Cl4(PPh2)4(PnPr3)2] (M = Zn,Cd)

New Phosphido-bridged Multinuclear Complexes of Ag, Cd and Zn. The Crystal Structures of [Ag₄(PPh₂)₄(PMe₃)₄], [Ag₆(PPh₂)₆(P^tBu₃)₂] and [M₄Cl₄(PPh₂)₄(PⁿPr₃)₂] (M = Zn, Cd) AgCl reacts with Ph₂PSiMe₃ in the presence of a tertiary Phosphine PMe₃ or P^tBu₃ to form the multinuclear complexes [Ag₄(PPh₂)₄(PMe₃)₄] ( 1 ) and [Ag₆(PPh₂)₆(P^tBu₃)₂] ( 2 ). In analogy to that MCl₂ reacts with Ph₂PSiMe₃ in the presence of PⁿPr₃ to form the two multinuclear complexes [M₄Cl₄(PPh₂)₄(PⁿPr₃)₂] (M = Zn ( 3 ), Cd ( 4 )). The structures were characterized by X-ray single crystal structure analysis ( 1 : space group Pna2₁ (Nr. 33), Z = 4, a = 1 313.8(11) pm, b = 1 511.1(6) pm, c = 4 126.0(18) pm, 2 : space group P–1 (Nr. 2), Z = 2, a = 1 559.0(4) pm, b = 1 885.9(7) pm, c = 2 112.4(8) pm, α = 104.93(3)°, β = 94.48(3)°, γ = 104.41(3)°; 3 : space group C2/c (Nr. 15), Z = 4, a = 2 228.6(6) pm, b = 1 847.6(6) pm, c = 1 827.3(6) pm, β = 110.86(2); 4 : space group C2/c (Nr. 15), Z = 4, a = 1 894.2(9) pm, b = 1 867.9(7) pm, c = 2 264.8(6) pm, β = 111.77(3)°). 3 and 4 may be considered as intermediates on the route towards polymeric [M(PPh₂)₂]_n (M = Zn, Cd).     

New 11-vertex osmacarborane 1,1-(PPh3)2-1-H-3-O(CH2)4-isonido-1,2,4-OsC2B8H9

Russian Chemical Bulletin - Hydride-containing 1,1-(PPh3)2-1-H-3-O(CH2)4-isonido-1,2,4-OsC2B8H9 osmacarborane bearing a charge-compensated ligand was synthesized via a reaction of the deprotonated...