The New Fluoro‐tris(pentafluoroethyl)borate Anion [(C2F5)3BF]—, Unexpected Formation of [(C2F5)3BH]— as a By‐Product. Das neue Fluoro‐tris(pentafluoroethyl)borat Anion [(C2F5)3BF]—, unerwartete Bildung des Nebenprodukts [(C2F5)3BH]—

Dimethylamine‐tris(pentafluoroethyl)borane (C₂F₅)₃B · NHMe₂ ( 1 ) has been obtained from C₂F₅I, Br₂BNMe₂ and tris(diethylamino)phosphane in sulfolane. Alkylation using CH₃I/KOH yielded the trimethylamine‐tris(pentafluoroethyl)borane (C₂F₅)₃B · NMe₃ ( 2 ). Compound 2 reacts with NEt₃×3HF at 200—204 °C under replacement of the trimethylamine ligand to form the novel fluoro‐tris(pentafluoroethyl)borate anion [(C₂F₅)₃BF]^— ( 3 ) in good yield. Side products are the hydroxy‐tris(pentafluoroethyl)borate [(C₂F₅)₃BOH]^— ( 4 ) and the hydrido‐tris(pentafluoroethyl)borate [(C₂F₅)₃BH]^— ( 5 ).     

Fluoroborates by Cleavage of Trimethylamine‐bis(trifluoromethyl)boranes with NEt3 × 3 HF. Structures of C6F5(CF3)2B · NMe3, K[C6H5CH2(CF3)2BF], and K[C6H5(CF3)2BF]

Trimethylamine‐bis(trifluoromethyl)boranes R(CF₃)₂B · NMe₃ (R = cis/trans‐CF₃CF=CF ( 1/2 ), HC≡C ( 3 ), H₂C=CH ( 4 ), C₂H₅ ( 5 ), C₆H₅CH₂ ( 6 ), C₆F₅ ( 7 ), C₆H₅ ( 8 )) react with NEt₃ × 3 HF depending on the nature of R at 155–200 °C under replacement of the trimethylamine ligand to form the corresponding fluoro‐bis(trifluoromethyl)borates [R(CF₃)₂BF]^– ( 1 a/2 a – 8 a ). The structures of 7 , K[C₆H₅CH₂(CF₃)₂BF] ( K‐6 a ), and K[C₆H₅(CF₃)₂BF] ( K‐8 a ) have been investigated by single‐crystal X‐ray diffraction. In 7 the CF₃ groups make short repulsive contacts with NMe₃ and C₆F₅ entities – the B–CF₃ bonds being unusually long. The B–F bond lengths of K‐6 a and K‐8 a (1.446(3) and 1.452(2) Å, respectively) are long for a fluoroborate.     

Preparation and Structure of [Me3N(CF3)2BCCB(CF3)2NMe3]

Bis‐trimethylamine‐ethynyl‐di‐bis(trifluoromethyl)borane [Me₃N(CF₃)₂BCCB(CF₃)₂NMe₃] ( 1 ) has been prepared from trimethylamine‐ethynyl‐bis(trifluoromethyl)borane, [HCCB(CF₃)₂NMe₃], and dimethylamino‐bis(trifluoromethyl)borane, (CF₃)₂BNMe₂. The structure of 1 has been determined by x‐ray crystallography. In the solid state the molecule possesses crystallographic C_i symmetry. The acetylenic attachment to the boron atom is characterized by a short B–C bond length of 1.565(4) Å and an essentially linear B–C–C′ bond angle of 178.1(4)°.     

Umsetzung von C(NMe2)4 mit Ni(CO)4 – Synthesen und Strukturen von [C(NMe2)3][(CO)3NiC(O)NMe2], [C(NMe2)3]2[Ni5(CO)12] und [C(NMe2)3]3[Ni6(CO)12][O2CNMe2]

Reaction of C(NMe₂)₄ with Ni(CO)₄ – Syntheses and Structures of [C(NMe₂)₃][(CO)₃NiC(O)NMe₂], [C(NMe₂)₃]₂[Ni₅(CO)₁₂], and [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] The reaction of C(NMe₂)₄ with Ni(CO)₄ in THF produces the carbamoyl complex [C(NMe₂)₃][(CO)₃NiC(O)NMe₂] ( 1 ); side products are the purple cluster compound [C(NMe₂)₃]₂[Ni₅(CO)₁₂] · THF ( 2 · THF) and the red cocristallization product [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] ( 3 ). All compounds were studied by X‐ray diffraction analyses. The cations of 3 are all disordered but not those of 1 and 2 . The unit cell of 1 contains two crystallographically independent anions (I and II) which differ in the dihedral angle between the plane of the carbamoyl ligand and the plane defined by the atoms C_Carbamoyl–Ni–CO amounting 0° in the anion I and 18° in the anion II.     

[2+4] and [2+2] Cycloaddition Reactions of N‐Sulfinyl Carboxylic Acid Amides with (CF3)2BNMe2. Crystal Structure of cyclo‐(CF3)2B‐NMe2‐S(=O)‐N=C(p‐CH3C6H4)‐O

N‐sulfinylacylamides R‐C(=O)‐N=S=O react with (CF₃)₂BNMe₂ ( 1 ) to form, by [2+4] cycloaddition, six‐membered rings cyclo‐(CF₃)₂B‐NMe₂‐S(=O)‐N=C(R)‐O for R = Me ( 2 ), t‐Bu ( 3 ), C₆H₅ ( 4 ), and p‐CH₃C₆H₄ ( 5 ) while N‐sulfinylcarbamic acid esters R‐O‐C(=O)‐N=S=O react with 1 to yield mixtures of six‐membered (cyclo‐(CF₃)₂B‐NMe₂‐S(=O)‐N=C(OR)‐O) and four‐membered rings (cyclo‐(CF₃)₂B‐NMe₂‐S(=O)‐N(C=O)OR) for R = Me ( 6 and 9 ), Et ( 7 and 10 ), and C₆H₅ ( 8 and 11 ). The structure of 5 has been determined by X‐ray diffraction.     

Synthesen und Eigenschaften von Pentafluorethylkupfer(I)‐ und ‐(III)‐Verbindungen: Cu(C2F5) · D, [Cu(C2F5)2]– und (C2F5)2CuSC(S)N(C2H5)2

Syntheses and Properties of Pentafluoroethylcopper(I) and ‐copper(III) Compounds: CuC₂F₅ · D, [Cu(C₂F₅)₂]^–, and (C₂F₅)₂CuSC(S)N(C₂H₅)₂ The reactions of Cd(C₂F₅)₂ · D and Zn(C₂F₅)₂ · D (D = 2 CH₃CN, 2 DMF), respectively, with copper(I) halides in the presence of halides quantitatively yield the CuC₂F₅ compounds CuC₂F₅ · D and [Cu(C₂F₅)₂]^–. The CuC₂F₅ complexes are identified by NMR spectroscopy, while [Cu(C₂F₅)₂]^– is isolated as PNP salt (PNP = (C₆H₅)₃PNP(C₆H₅)₃⁺). Both compounds are excellent C₂F₅ group transfer reagents, even at low temperature. Oxidation of [Cu(C₂F₅)₂]^– with [(C₂H₅)₂NC(S)S]₂ yields the crystalline Cu(III) compound (C₂F₅)₂CuSC(S)N(C₂H₅)₂ (monoclinic, C2/c).     

Über die Reaktion von Cp2TiCl2 mit [C(NMe2)3][(CO)4FeC(O)NMe2] – Kristallstruktur von [C(NMe2)3]2[FeCl4]

Concerning the Reaction of Cp₂TiCl₂ with [C(NMe₂)₃][(CO)₄FeC(O)NMe₂] – Crystal Structure of [C(NMe₂)₃]₂[FeCl₄] The title compound forms by the reaction of Cp₂TiCl₂ with [C(NMe₂)₃][(CO)₄FeC(O)NMe₂] in THF solution. It crystallizes in the space group Pbcn with a = 1 566.6(3); b = 976.4(2); c = 1 580.4(4) pm; Z = 4; R = 3.8%. Each [FeCl₄]^2? in is surrounded by eight cations. Two cations each are connected with one Cl atom by relatively short H …? Cl contacts leading to a distortion of the tetrahedral geometry of the anion.     

Formation of Unusual Complexes from the Reaction of [C(NMe2)3][(CO)4Fe{C(O)NMe2}] with InMe3; Crystal Structures of [C(NMe2)3]3[Fe2(CO)6(μ‐CO){μ‐InFe(CO)4(μ‐O2CNMe2)InFe(CO)4}] and [C(NMe2)3]2[{(CO)4Fe}2In(O2CNMe2)]·THF

The carbamoyl complex [C(NMe₂)₃][(CO)₄Fe{C(O)NMe₂}] ( 1 ) reacts with InMe₃ under loss of the methyl groups to produce a variety of compounds from which only the anionic cluster complexes [C(NMe₂)₃]₃[Fe₂(CO)₆(μ‐CO){μ‐InFe(CO)₄(μ‐O₂CNMe₂)InFe(CO)₄}] ([C N ₃]₃[ 2 ]) and [C(NMe₂)₃]₂[{(CO)₄Fe}₂In(O₂CNMe₂)]·THF ([C N ₃]₂[ 3 ]·THF) could be crystallized and characterized by X‐ray analyses. The anion [ 2 ]^3? has a Fe₂(CO)₉‐like structure and both anions contain the carbaminato ligand either in a bridging or in a chelating function.     

Darstellung,Kristallstruktur und quantenchemische Berechnung von [C(NMe2)3]2[(CO)4FeInCl3]

Preparation, Structure, and Quantum Chemical Calculation of [C(NMe₂)₃]₂[(CO)₄FeInCl₃] The title compound ( 1 ) has been obtained as colorless crystals by reacting InCl₃ with [C(NMe₂)₃][(CO)₄FeC(O)NMe₂] in THF solution. The crystal structure determination (monoclinic, C2/c) shows the presence of separate ions with one disordered and one non disordered cation. In the dianion the CO groups of the trigonal bipyramidal coordinated iron atom and the Cl atoms of the tetrahedral coordinated indium atom form a staggered conformation with a relatively short In–Fe bond distance of 252 pm. Quantum Chemical DFT calculations of [CO)₄FeInCl₃]^2– show that the Fe–In bond has a strong ionic character and that it should be considered as an adduct of [Fe(CO)₄]^2– and InCl₃.     

Two Different Structural Motifs Observed for Dimeric Dialkylaluminum and Dialkylgallium Alkynides [R2E‐C≡C‐C6H5]2

The dialkylaluminum and dialkylgallium alkynides [R₂E‐C≡C‐R′]₂ (R = Me, CMe₃; E = Al, Ga; R′ = Ph) containing C≡C triple bonds attached to their central aluminum or gallium atoms are easily obtained by the reactions of dialkylelement chlorides with lithium alkynides or by treatment of the corresponding alkyne R‐C≡C‐H with dialkylaluminum or dialkylgallium hydrides. The first reaction is favored by the precipitation of LiCl, the second one by the formation of elemental hydrogen. All products form dimers in which the carbanionic carbon atoms of the alkynido groups adopt bridging positions, but, interestingly, different types of molecular structures were observed depending on the steric demand of the substituents terminally attached to the aluminum or gallium atoms. The small methyl substituents gave structures in which the aluminum or gallium atoms seemed to be side‐on coordinated by the C≡C triple bonds of almost linear E‐C≡C groups. In contrast, the more bulky tert‐butyl groups forced an arrangement in which the C≡C triple bonds were perpendicular to the E‐E axis of the molecules. Different bonding modes result, which were analyzed by quantum‐chemical calculations.     

Preparation and characterization of [Hg[P(C6F5)2]2], [Hg[(mu-P(C6F5)2)W(CO)5]2], and [Hg[(mu-P(CF3)2)W(CO)5]2] and the X-ray crystal structure of [Hg[(mu-P(C6F5)2)W(CO)5]2].2DMF

The thermally unstable compound [Hg[P(C(6)F(5))(2)](2)] was obtained from the reaction of mercury cyanide and bis(pentafluorophenyl)phosphane in DMF solution and characterized by multinuclear NMR spectroscopy. The thermally stable trinuclear compounds [Hg[(mu-P(CF(3))(2))W(CO)(5)](2)] and [Hg[(mu-P(C(6)F(5))(2))W(CO)(5)](2)] are isolated and completely characterized. The higher order NMR spectra exhibiting multinuclear satellite systems have been sufficiently analyzed. [Hg[(mu-P(CF(3))(2))W(CO)(5)](2)].2DMF crystallizes in the monoclinic space group C2/c with a = 2366.2(3) pm, b = 1046.9(1) pm, c = 104.0(1) pm, and beta = 104.01(1) degrees. Structural, NMR spectroscopic, and vibrational data prove a weak coordination of the two DMF molecules. Structural, vibrational, and NMR spectroscopic evidence is given for a successive weakening of the pi back-bonding effect of the W-P bond in the order [W(CO)(5)PH(R(f))(2)], [Hg[(mu-P(R(f))(2))W(CO)(5)](2)], and [W[P(R(f))(2)](CO)(5)](-) with R(f) = C(6)F(5) and CF(3). The pi back-bonding effect of the W-C bonds increases vice versa.     

Schwermetall-π-Komplexe. IX. Die Kettenpolymere [(1,2- (CH3)2C6H4BiCl3)2], [(1,3) (CH3)2C6H4BiCl3)2] und [(1,4- (CH3)2C6H4BiCl3)2]

Heavy Metal π-Complexes. IX. The Chain Polymers [(1,2- (CH₃)₂C₆H₄BiCl₃)₂], [(1,3- (CH₃)₂C₆H₄BiCl₃)₂] and [(1,4- (CH₃)₂C₆H₄BiCl₃)₂] In the crystal structures of the three solid state complexes (C₆H₄(CH₃)₂BiCl₃ (C₆H₄(CH₃)₂ = o-xylene: 1 , m-xylene: 2 , p-xylene: 3 ) quasi-dimeric units of almost undistorted, arene coordinated BiCl₃ fragments can be found that are further associated via additional Bi? Cl contacts to form one-dimensional polymeric chains. Whereas the chains of 2 and 3 are constituted by Bi₂Cl₂ four-membered rings only, further Cl-bridging in 1 leads to additional trigonal-bipyramidal arrangements with Bi atoms exhibiting coordination numbers of 3 + 3 + 1 and 3 + 2 + 1, respectively (prim. + sec. Cl contacts + arene). The arene-metal bonding is characterized by Bi-arene distances in the range from 297 – 306 pm, including ring slippages of 24 –41 pm and 73 pm with the Bi atoms being six and seven coordinated, respectively. The direction of this slipping with respect to the arene's methylation sites cannot be understood in terms of electronic influences but is shown to be caused by steric demands. The values IP₁ of the arenes prove to determine the colours of the complexes.