Zur Umsetzung von Kupfer(I)‐ und Kupfer(II)‐Salzen mit P(C6H4CH2NMe2‐2)3 ‐ die Festkörperstrukturen von {[P(C6H4CH2NMe2‐2)3]CuOClO3}ClO4, {[P(C6H4CH2NMe2‐2)3]Cu}ClO4, [P(C6H4CH2NMe2‐2)3]CuONO2 und [P(C6H4CH2NMe2‐2)2(C6H4CH2NMe2H+NO3‐‐2)]CuONO2

Reaction Behaviour of Copper(I) and Copper(II) Salts Towards P(C₆H₄CH₂NMe₂‐2)₃ ‐ the Solid‐State Structures of {[P(C₆H₄CH₂NMe₂‐2)₃]CuOClO₃}ClO₄, {[P(C₆H₄CH₂NMe₂‐2)₃]Cu}ClO₄, [P(C₆H₄CH₂NMe₂‐2)₃]CuONO₂ and [P(C₆H₄CH₂NMe₂‐2)₂(C₆H₄CH₂NMe₂H⁺NO₃^‐‐2)]CuONO₂ The reaction behaviour of P(C₆H₄CH₂NMe₂‐2)₃ ( 1 ) towards different copper(II) and copper(I) salts of the type CuX₂ ( 2a : X = BF₄, 2b : X = PF₆, 2c : X = ClO₄, 2d : X = NO₃, 2e : X = Cl, 2f : X = Br, 13 : X = O₂CMe) and CuX ( 5a : X = ClO₄, 5b : X = NO₃, 5c : X = Cl, 5d : X = Br) is discussed. Depending on X, the transition metal complexes [P(C₆H₄CH₂NMe₂‐2)₃Cu]X₂ ( 3a : X = BF₄, 3b : X = PF₆), {[P(C₆H₄CH₂NMe₂‐2)₃]CuX}X ( 4 : X = ClO₄, 11a : X = Cl, 11b : X = Br, 14 : X = O₂CMe), {[P(C₆H₄CH₂NMe₂‐2)₃]Cu}ClO₄ ( 6 ), [P(C₆H₄CH₂NMe₂‐2)₃]CuX ( 7a : X = Cl, 7b : X = Br, 10 : X = ONO₂), [P(C₆H₄CH₂NMe₂‐2)₂(C₆H₄CH₂NMe₂H⁺NO₃^‐‐2)]CuONO₂ ( 9 ) and [P(C₆H₄CH₂NMe₂‐2)₃]CuCl}CuCl₂ ( 12 ) are accessible. While in 3a , 3b and 6 the phosphane 1 preferentially acts as tetrapodale ligand, in all other species only the phosphorus atom and two of the three C₆H₄CH₂NMe₂ side‐arms are datively‐bound to the appropriate copper ion. In solution a dynamic behaviour of the latter species is observed. Due to the coordination ability of X in 3a , 3b and 6 non‐coordinating anions X^‐ are present. However, in 4 one of the two perchlorate ions forms a dative oxygen‐copper bond and the second perchlorate ion acts as counter ion to {[P(C₆H₄CH₂NMe₂‐2)₃]CuOClO₃}⁺. In 7 , 9 and 10 the fragments X (X = Cl, Br, ONO₂) form a σ‐bond with the copper(I) ion. The acetate moiety in 14 acts as chelating ligand as it could be shown by IR‐spectroscopic studies. All newly synthesised cationic and neutral copper(I) and copper(II) complexes are representing stable species. Redox processes are involved in the formation of 9 and 12 by reacting 1 with 2 . The solid‐state structures of 4 , 6 , 9 and 10 are reported. In the latter complexes the copper(II) ( 4 ) or copper(I) ion ( 6 , 9 , 10 ) possesses the coordination number 4. This is achieved by the formation of a phosphorus‐ and two nitrogen‐copper‐ ( 4 , 9 , 10 ) or three ( 6 ) nitrogen‐copper dative bonds and a coordinating ( 4 ) or σ‐binding ( 9 , 10 ) ligand X. In 6 all three nitrogen and the phosphorus atoms are coordinatively bound to copper, while X acts as non‐coordinating counter‐ion. Based on this, the respective copper ion occupies a distorted tetrahedral coordination sphere. While in 4 and 10 a free, neutral Me₂NCH₂ side‐arm is present, which rapidly exchanges in solution with the coordinatively‐bound Me₂NCH₂ fragments, this unit is protonated in 10 . NO₃^‐ acts as counter ion to the CH₂NMe₂H⁺ moiety. In all structural characterized complexes 6‐membered boat‐like CuPNC₃ cycles are present.     

Synthesis and characterization of novel chelated dimethylamino lithium alkoxides: molecular structures of [1‐LiOC(C6H11)2‐2‐NMe2C6H4]2 and [1‐LiOCPh2CH2‐2‐NMe2C6H4]2

From the reaction of 1‐HOCPh₂‐2‐NMe₂C₆H₄ ( 1 ), 1‐HOC(C₆H₁₁)₂‐2‐NMe₂C₆H₄ ( 2 ) and 1‐HOCPh₂CH₂‐2‐NMe₂C₆H₄ ( 3 ) with n‐BuLi in diethyl ether, the solvent‐free chelated dimethylamino lithium alkoxides [1‐LiOCPh₂‐2‐NMe₂C₆H₄]₂ ( 4 ), [1‐LiOC(C₆H₁₁)₂‐2‐NMe₂C₆H₄]₂ ( 5 ) and [1‐LiOCPh₂CH₂‐2‐NMe₂C₆H₄]₂ ( 6 ) were obtained. The lithium alkoxides 4 – 6 were characterized by ¹H, ⁷Li, and ¹³C NMR spectroscopy. Crystal structure determinations of 5 and 6 were carried out. Compounds 5 and 6 are examples of structurally characterized solvent‐free chelated dimethylamino lithium alkoxides and 6 is a rare example of this type containing a seven‐membered ring. Copyright © 2002 John Wiley & Sons, Ltd.     

The Homoleptic U(NCSe)84– Anion in (Pr4N)4U(NCSe)8·2CFCl3 and Th(NCSe)4(OP(NMe2)3)4·0.5CH3CN·0.5H2O: First Structurally Characterised Actinide Isoselenocyanates

The neutral thorium complex Th(NCSe)₄(OP(NMe₂)₃)₄ and homoleptic octa(isoselenocyanato)uranate anion U(NCSe)₈^4– in (Pr₄N)₄U(NCSe)₈·2CFCl₃ ( 1 ) were synthesised and structurally characterised. (Pr₄N)₄U(NCSe)₈·2CFCl₃ contains the U^IV anion U(NCSe)₈^4– and was characterised using IR spectroscopy and single‐crystal X‐ray diffraction. Th(NCSe)₄(OP(N(CH₃)₂)₃)₄·0.5CH₃CN·0.5H₂O ( 2 ) was characterised using IR and Raman spectroscopy, as well as ³¹P{¹H}, ¹⁵N{¹H}, ¹⁴N{¹H}, ¹³C{¹H}, ¹H and ⁷⁷Se NMR spectroscopy and structurally characterised using single‐crystal X‐ray diffraction. The U(NCSe)₈^4– anion and Th(NCSe)₄(OP(N(CH₃)₂)₃)₄·0.5CH₃CN·0.5H₂O complex are the first structurally characterised actinide‐isoselenocyanates. The crystal structures shows an approximate square antiprismatic arrangement of the ligands around the actinide(IV) atoms.     

Bipy,Phen und P(C6H4CH2NMe2‐2)3 in der Synthese kationischer Silber(I)‐Komplexe; die Festkörperstrukturen von [P(C6H4CH2NMe2‐2)3]AgOTf und [Ag(phen)2]OTf

Bipy, Phen, and P(C₆H₄CH₂NMe₂‐2)₃ in the Synthesis of Cationic Silver(I) Complexes; the Solid‐State Structures of [P(C₆H₄CH₂NMe₂‐2)₃]AgOTf and [Ag(phen)₂]OTf The reaction of [P(C₆H₄CH₂NMe₂‐2)₃]AgX ( 1a , X = OTf; 1b , X = OClO₃) with equimolar amounts of L^capL ( 2a , L^capL = 2, 2′‐bipyridine, bipy; 2b , L^capL = 4, 4′‐dimethyl‐2, 2′‐bipyridine, bipy′; 2c , L^capL = 1, 10‐phenanthroline, phen) leads to the formation of the cationic complexes {[P(C₆H₄CH₂NMe₂‐2)₃]Ag(L^capL)}⁺X^— (L^capL = bipy: 3a , X = OTf; 3b , X = ClO₄; L^capL = bipy′: 3c , X = OTf; 3d , X = ClO₄; L^capL = phen: 3e , X = OTf; 3f , X = ClO₄) in which the building blocks L^capL and P(C₆H₄CH₂NMe₂‐2)₃ act as bidentate chelating ligands and are datively‐bound to the silver atom. Spectroscopic studies reveal that on the NMR time‐scale the phosphane group is dynamic with exchanging the respective Me₂NCH₂ built‐in arms. While complex 3e is stable in the solid‐state, it appeared that solutions of 3e start to decompose upon precipitation of colloidal silver when they are heated or irradiated with light, respectively. Appropriate work‐up of the reaction mixture allows the isolation of the phosphane P(C₆H₄CH₂NMe₂‐2)₃ ( 5 ) along with [Ag(phen)₂]OTf ( 4 ). The solid‐state structures of neutral 1a and cationic 4 are reported. Mononuclear 1a crystallizes in the monoclinic space group P2₁/c with the cell parameters a = 16.7763(2), b = 14.7892(2), c = 25.44130(10)Å, β = 106.1260(10), V = 6063.83(11)ų and Z = 4 with 8132 observed unique reflections (R₁ = 0.0712), while 4 crystallizes in the monoclinic space group C2/c with the cell parameters a = 26.749(3), b = 7.1550(10), c = 26.077(3)Å, β = 113.503(2), V = 4576.8(10)ų and Z = 4 with 6209 observed unique reflections (R₁ = 0.0481). The unit cell of 1a consists of two independent molecules. In both molecules the silver atom possesses a distorted tetrahedral coordination sphere and a boat‐like conformation for the six‐membered AgPNCH₂C_2/phenyl cycles is found. In 4 , as typical for 1a , the silver atom possesses the coordination number 4. The two phen ligands are tilted by 40.63°. The OTf group is acting as non‐coordinating counter ion.     

Oxidative Reactions of the MoIV Dialkyl Complex [{(3‐CF3C6H4NCH2CH2)2NMe}Mo(CH2SiMe3)2]

The structure of [(CF₃N₂NMe)Mo(CH₂SiMe₃)₂] (in which (CF₃N₂NMe)^2? is [(3‐CF₃C₆H₄NCH₂CH₂)₂NMe]^2?) is approximately trigonal bipyramidal with one axial and one equatorial alkyl ligand. Heating of solutions of [(CF₃N₂NMe)Mo(CH₂SiMe₃)₂] in [D₆]benzene in the presence of five equivalents of 2‐butyne led to diamagnetic [(CF₃N₂NMe)Mo(CHSiMe₃)(η²‐MeC?CMe)], whose structure is approximately square pyramidal with the alkyne occupying the axial site. Addition of one equivalent of cyclohexene sulfide to [(CF₃N₂NMe)Mo(CH₂SiMe₃)₂] at room temperature produced the diamagnetic, dimeric molybdenum(IV) sulfido complex, [{(CF₃N₂NMe)MoS}₂]. This complex is composed of two approximately trigonal bipyramidal centers, each containing one axial and one equatorial sulfur atom. Oxidation of [(CF₃N₂NMe)Mo(CH₂SiMe₃)₂] with hexachloroethane resulted in formation of tetramethylsilane, HCl, and the sparingly soluble, red alkylidyne complex, [{(CF₃N₂NMe)Mo(CSiMe₃)Cl}₂]. This complex forms a dimer through bridging chlorides. The oxidation reactions of [(CF₃N₂NMe)Mo(CH₂SiMe₃)₂] with 2‐butyne, cyclohexene sulfide, or C₂Cl₆ are all proposed to proceed by α‐hydrogen abstraction in the Mo^VI species to yield (initially) the Mo?CHSiMe₃ species and tetramethylsilane.     

Four‐ and Five‐Coordinate Gallium Complexes Stabilized by Bidentate 2‐(Dimethylaminomethyl)Pyrrole Ligand: Molecular Structures of Ga[NC4H3(CH2NMe2)‐2]3 and GaMe2[NC4H3(CH2NMe2)‐2]

Treatment of GaCl₃ with one equiv of Li[NC₄H₃(CH₂NMe₂)‐2] (n = 1, 2, 3) in diethyl ether at ?78 °C yields GaCl_3‐n[NC₄H₃(CH₂NMe₂)‐2]_n (n = 1, 1 ; n = 2, 2 ; n = 3, 3 ). Compound 1 reacts with two equiv of RLi to afford GaR₂[NC₄H₃(CH₂NMe₂)‐2] ( 4a, R=Me; 4b, R=Bu ) via transmetallation. Reacting 2 with one equiv of RLi in diethyl ether, 3 and 4 are formed via ligand redistribution. Variable temperature ¹H NMR spectroscopic experiments reveal that the five‐coordinate gallium compound 3 is fluxional and results in a coalescence temperature at 5 °C, at which ΔG^≠ is calculated at ca. 10.4 Kcal/mole. All the new compounds have been characterized by ¹H and ¹³C NMR spectroscopy and the structures of compounds 3 and 4a have also been determined by X‐ray crystallography.     

Synthese monomerer Silber(I)‐Halogenid‐Komplexe mit T‐förmigem Bau – Kristallstrukturanalyse von [P(C6H4CH2NMe2‐2)3]AgBr

Synthesis of Monomeric T‐Shaped Silver(I) Halide Complexes – Crystal Structure Analysis of [P(C₆H₄CH₂NMe₂‐2)₃]AgBr Treatment of the tetrapodal phosphane P(C₆H₄CH₂NMe₂‐2)₃ ( 1 ) with equimolar amounts of the silver(I) halides AgX ( 2 a : X = Cl, 2 b : X = Br) produces in tetrahydrofuran at 25 °C the monomeric silver(I) complexes [P(C₆H₄CH₂NMe₂‐2)₃]AgX with planar coordination at the Ag atoms ( 3 a : X = Cl, 3 b : X = Br) in excellent yields. From complex 3 b a single X‐ray crystal structure analysis was carried out. Mononuclear 3 b crystallizes in the monoclinic space group P2₁/c with the cell parameters a = 14.504(6), b = 11.034(3), c = 17.604(5) Å, β = 102.86(4)°; V = 2746.6(16) ų; Z = 4; 2953 observed unique reflections, R₁ = 0.0805. Complex 3 b consists of monomeric sub‐units with a planar T‐shaped arrangement formed by the atoms Ag1, N1, P1 as well as Br1, whereby the P1–Ag1–Br1 array is almost linear orientated.     

Reactivity of the inversely polarized phosphaalkenes RP=C(NMe2)2 (R = tBu, Me3Si, H) towards arylcarbene complexes [(CO)5M=C(oEt)Ar] (Ar= Ph, M = Cr, W; Ar = 2-MeC6H4, 2-MeOC6H4, M = W)

The reaction of the arylated Fischer carbene complexes [(CO)5M=C(OEt)Ar] (Ar=Ph; M = Cr, W; 2-MeC6H4; 2-MeOC6H; M = W) with the phosphaalkenes RP=C(NMe2), (R=tBu, SiMe3) afforded the novel phosphaalkene complexes [[RP=C(OEt)Ar]M(CO)5] in addition to the compounds [(RP=C(NMe2)2]M(CO)5]. Only in the case of the R = SiMe3 (E/Z) mixtures of the metathesis products were obtained. The bis(dimethylamino)methylene unit of the phosphaalkene precursor was incorporated in olefins of the type (Me2N)2C=C(OEt)(Ar). Treatment of [(CO)5W=C(OEt)(2-MeOC6H4)] with HP=C(NMe2)2 gave rise to the formation of an E/Z mixture of [[(Me2N)2CH-P=C(OEt)(2-MeOC6H4)]W(CO)5] the organophosphorus ligand of which formally results from a combination of the carbene ligand and the phosphanediyl [P-CH(NMe2)2]. The reactions reported here strongly depend on an inverse distribution of alpha-electron density in the phosphaalkene precursors (Pdelta Cdelta+), which renders these molecules powerfu] nucleophiles.     

Formation of Methane versus Benzene in the Reactions of (C5Me5)2Th(CH3)2 with [CH3PPh3]X (X=Cl,Br, I) Yielding Thorium‐Carbene or Thorium‐Ylide Complexes

The reaction of (C₅Me₅)₂Th(CH₃)₂ with the phosphonium salts [CH₃PPh₃]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C₅Me₅)₂Th[CHPPh₃]X, rare terminal phosphorano‐stabilized carbenes with thorium. These complexes feature the shortest thorium–carbon bonds (≈2.30 Å) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X=Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C₅Me₅)₂Th[κ²‐(C,C′)‐(CH₂)(CH₂)PPh₂]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH₃PPh₃]X, X=Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene.