Alternativ-Liganden. XXVI [1]. M(CO)4L-Komplexe (M  Cr,Mo, W) der Chelatliganden Me2ESiMe2(CH2)2E′Me2 (Me  CH3; E  P,As; E′  N,P, As)

Alternative Ligands. XXVI. M(CO)₄ L-Complexes (M ? Cr, Mo, W) of the Chelating Ligands Me₂ESiMe₂(CH₂)₂E′ Me₂ (Me ? CH₃; E ? P, As; E′ ? N, P, As) The reaction of M(CO)₄NBD (NBD = norbornadiene; M ? Cr, Mo, W) with the ligands Me₂ESiMe₂(CH₂)₂E′ Me₂ yields the chelate complexes (CO)₄M[Me₂ESiMe₂]) for E,E′ ? P, As, but not for E and /or E′ ? N. The NSi group is not suited for coordination because of strong (p-d)π-interaction. In the case of the ligands with E ? P or As and E′ ? N chelate complexes can be detected in the reaction mixture, but isolable products are complexes with two ligands coordinated via the E donor group. The new compounds are characterized by analytical and spectroscopic (IR, NMR, MS) investigations. The spectroscopic data are also used to deduce the coordinating properties of the ligands. X-ray diffraction studies of the molybdenum complexes (CO)₄Mo[Me₂ESiMe₂(CH₂)₂AsMe ₂] (E ? P, As) in accord with the observed coordination effects show only small differences between SiE and CE donor functions. Attempts to use the ligands Me₂ESiMe₂(CH₂)₂AsMe₂ (E ? P, As) for the preparation of Fe(CO)₃L complexes result in the fission of the SiE bonds and the formation of the binuclear systems Fe₂(CO)₆(EMe₂)₂ (E ? P, As) together with the disilane derivative [Me₂Si(CH₂)₂AsMe₂]₂.     

Synthese und Struktur von MII[AuF4]2 (MII  Cd,Hg)

Synthesis and Structure of M^II[AuF₄]₂ (M^II ? Cd, Hg) Cd[AuF₄]₂ and the isotypic compound Hg[AuF₄]₂, both are yellow, crystallize tetragonal in the space-group P4/mcc-D (No. 124) with a = 575.0/575.6 pm, c = 1034.8/1042.3 pm and Z = 2. The single-crystals were obtained by solid-state reactions in goldtubes.     

Synthese,Strukturen und Reaktivität von [(2,4,6-Ph3C6H2)Te(μ2-O)X]2 (X  Br und I)

Synthesis, Structures, and Reactivity of [(2,4,6-Ph₃C₆H₂)Te(μ₂-O)X]₂ (X ? Br, I) [(2,4,6-Ph₃C₆H₂)Te]₂ reacts with iodine affording the aryltellurenic halide (2,4,6-Ph₃C₆H₂)TeI, which is oxidized by oxygen to yield [(2,4,6-Ph₃C₆H₂)Te(μ₂-O)I]₂. It crystallizes with two molecules of dichloromethane in the monoclinic space group P2₁/c with a unit cell of the dimensions a = 911.3(4); b = 1153.3(2); c = 2244.1(9) pm; β = 93.53(2)°, Z = 2). The analogues bromo compound [(2,4,6-Ph₃C₆H₂)Te(μ₂-O)Br]₂ is obtained by the reaction of [(2,4,6-Ph₃C₆H₂)Te(μ₂-O)I]₂ with NH₄Br. It crystallizes with two molecules of xylene in the monoclinic space group P2₁/n (a = 1067.5(5); b = 1018.4(4); c = 2486.5(8) pm; β = 101.71(2)°; Z = 2). Both compounds are built up by two (2,4,6-Ph₃C₆H₂)TeX units (X ? Br, I) which are linked by two oxgen bridges to form centrosymmetric molecules. The Te? O? Te angles are 102°. Distinct Te? O bond lengths have been found (191.4(2) and 208.6(2) pm in [(2,4,6-Ph₃C₆H₂)Te(μ₂-O)I]₂ and 189.8(4)/208.4(5 pm in the bromo compound).     

Synthese,Struktur und Reaktivität von Bis(dialkylamino)diphosphanen

Synthesis, Structure, and Reactivity of Bis(dialkylamino)diphosphines Starting with the aminochlorophosphines ⁱPr₂N? PCl₂ 1 and (ⁱPr₂N)₂P? Cl 2 , the synthesis of some new functionalized aminophosphines (ⁱPr₂N)₂P? SiMe₃ 3a , (ⁱPr₂N)₂P? SnMe₃ 3b , (ⁱPr₂N)(DMP)P? Cl 4 , ⁱPr₂N? P(SiMe₃)₂ 5 and ⁱPr₂N? P(SiMe₃)Cl 6 is reported. Reactions of 2 with different phosphides yield the aminodiphosphines (ⁱPr₂N)₂P? P(SiMe₃)₂ 7a , (ⁱPr₂N)₂P? P(SiMe₂^tBu)₂ 7b , (ⁱPr₂N)₂P? PPh₂ 8 and (ⁱPr₂N)₂P? PH₂ 9 . The phosphines 3a/b react with halogenophosphines to the aminohalogenodiphosphines (ⁱPr₂N)₂P? PCl₂ 10 , (ⁱPr₂N)₂P? P^tBuCl 11 and (ⁱPr₂N)₂P? P(NⁱPr₂)Cl 12 . The ambivalente aminophosphine 6 gives the aminotrichlorodiphosphine Cl(ⁱPr₂N)P? PCl₂ 13 after condensation with PCl₃, while the reactions with the corresponding lithiumphosphides yield the aminosilyldiphosphines (ⁱPr₂N)(SiMe₃)P? P(SiMe₃)₂ 14a and (ⁱPr₂N)(SiMe₃)P? P(SiMe₂^tBu)₂ 14b . The aminochlorophosphines 2/4 are reductively coupled with magnesium leading to the symmetrically substituted tetraaminodiphosphines (ⁱPr₂N)₂P? P(ⁱPr₂N)₂ 15a and DMP(ⁱPr₂N)P? P(ⁱPr₂N)DMP 15b . The functionalized aminosilyldiphosphine 7a is treated with methanol to yield the diphosphine (ⁱPr₂N)₂P? PH(SiMe₃) 16 and gives the lithium phosphinophosphide (ⁱPr₂N)₂P? PLi(SiMe₃) 17 after metallation with n-BuLi. The compounds are characterized by their NMR and mass spectra and the ³¹P-NMR values of the diphosphines are discussed according to their substituents. The crystal structures of 7b, 8 and 15b showing significantly differing conformations are presented.     

Lewis-Säure-Base-Reaktionen von Goldtrihalogeniden mit Bismuttrihalogeniden – Synthese und Kristallstrukturen von AuBiX6 (X  Cl,Br)

Lewis-Acid-Base-Reactions of Gold Trihalides with Bismuth Trihalides – Synthesis and Structures of AuBiX₆ (X ? CI, Br) Gold trihalides AuX₃ (X ? Cl, Br) react with bismuth trihalides in sealed glass ampoules to the 1 : 1 adducts AuBiX₆ (X ? Cl, Br). AuBiCl₆ is obtained by a chemical transport reaction at 220°C, whereas AuBiBr₆ was synthesized by solvothermal reaction in SiBr₄ at 150°C. Both compounds crystallize triclinic, space group P1 , Z = 4. AuBiCl₆; a = 698.3(4) pm; b = 1009.3(5) pm; c = 1381(1) pm; α = 104.98(5)°; β = 94.73(5)°; γ = 110.06(3)°; V = 867(1) · 10⁶ pm³. AuBiBr₆: a = 735.7(4) pm; b = 1055.7(5) pm; c = 1445(1) pm; α =104.88(5)°; β = 94.25(5)°; γ = 110.18(4)°; V =1001(1) ·10⁶pm³. The structures are build formally of square-planar [AuX₄]^? and chains of edge-connected ([BiX_4/2]⁺)_n units. Since each Bi ion is surrounded by eight halogenide ions in a square-antiprismatic form, the structure can alternatively be described as consisting of chains of edge sharing ([BiX₄X_4/2]^3?)_n antiprisms connected by Au³⁺ ions.     

Alternativ-Liganden. III. Koordinatives verhalten von chelatliganden des typs me2XSi(Me2)CH2XMe2 (X  N und/oder P: Me  CH3)

Co-ordinative Properties of Chelating Ligands of the Type Me₂XSi(Me₂)CH₂XMe₂ (X ? N and/or P; Me ? CH₃) The reactions of the ligands L ? Me₂XSi(Me₂)CH₂XMe₂ (X ? N and/or P; Me ? CH₃) with M(CO)₆ and M(CO)₄norbor (norbor ? norbornadiene) (M ? Cr, Mo), respectively, yield derivatives of the types M(CO)₅L, M(CO)₄L, and M(CO)₄L₂, respectively. M(CO)₅L compounds are formed from the hexacarbonyls with Me₂NSiMe₂CH₂PMe₂, whereas the ligand Me₂NSiMe₂CH₂NMe₂ does not afford analogous derivatives under the same conditions. Even on substitution of the diene-ligand in M(CO)₄norbor by Me₂NSiMe₂CH₂PMe₂ the chelate complexes M(CO)₄NMe₂SiMe₂CH₂PMe₂ are not obtained, but the cis-disubstituted products M(CO)₄[PMe₂CH₂SiMe₂NMe₂]₂ with phosphorus acting as donor atom are produced. The ligands Me₂PSiMe₂CH₂XMe₂(X ? N, P) give the chelate complexes M(CO)₄PMe₂SiMe₂CH₂XMe₂ in high yields. The new compounds were identified by analytical and spectroscopic (PMR, IR, mass spectra) methods.     

Synthese und Reaktivität von Diphenylphosphanyltrimethylsilylamin Ph2PN(H)SiMe3

Synthesis and Reactivity of the Diphenylphosphanyltrimethylsilylamine Ph₂PN(H)SiMe₃ The trimethylsilyliminotriphenylphosphoran Ph₃P=NSiMe₃ ( 1 ) reacts with sodium in THF under cleavage of one P–C_phenyl bond leading to the P^III‐species [(THF)₃Na(Ph₂PNSiMe₃)] ( 2 ). Reaction with NH₄Br or hydrolysis with water gives the diphenylphosphanyltrimethylsilylamine Ph₂PN(H)SiMe₃ ( 3 ) and in low yields the oxidized byproduct [(THF)Na(OOPPh₂)]_n ( 4 ) that can be synthesised directly in high yields in the reaction of Ph₂POOH and NaH in THF. 3 was reacted with an equimolar amount of Zn{N(SiMe₃)₂}₂ to give [(Me₃Si)₂NZnPh₂PNSiMe₃]₂ ( 5 ). 3 reacts with caesium under phosphorus‐phosphorus bond formation in a reductive substituent coupling reaction to give [(THF)Cs₂{Ph(NSiMe₃)P}₂]_n ( 6 ) where phosphorus(III) is reduced to phosphorus(II). Phosphorus‐phosphorus bond formation to give (Ph₂PNSiMe₃)₂ ( 7 ) where the phosphorus(III) centres are oxidized to P^IV is observed in the reaction of 3 with n‐BuLi and bismuthtrichloride.     

Silaheterocyklen. III. Erzeugung und Reaktivität von Di-tbutyl-Neopentylsilaethen,BuSiCHCH2But

Silaheterocycles. III. Synthesis and Reactivity of Di-^tbutylneopentylsilaethene, Bu Si?CHCH₂Bu^t The three di-^tbutylvinylsilanes BuSi(X)CH?CH₂ (X = H 5 , X = F 9 , X = Cl 22 ) are prepared by the reaction of their SiCl precursors with vinyl lithium. In the treatment with LiBu^t the first step is the generation of the α-lithio compound BuSi(X)CH(Li)CH₂Bu^t, the following reactions are governed by the nature of the substituent X and the reaction conditions (solvent, concentration, temperature). For X = H 2,3-LiH elimination leads to BuSi(H)CH?CHBu^t ( 7 ), with X = F or Cl Si?C formation by 1,2-LiX elimination competes with intermolecular Si-C-coupling producing BuSi(H)CH(SiBuCH?CHBu^t)CH₂Bu^t ( 13 ) as the main product. BuSi?CHCH₂Bu^t ( 1 ) probably coordinates to LiBu^t and reacts to yield BuSiCH?CHBu^t ( 3 ) and 7 , forms tetrabutyl-dineopentyl-1,3-disilacyclobutane 2 by cyclodimerization and 13 by addition of BuSi(X)CH(Li)CH₂Bu^t.