Monomeric lithium triazapentadienyl complexes

Treatment of 1,3,5-triazapentadienes [N{(C3F7)C(Mes)N}2]H and [N{(C3F7)C(Dipp)N}2]H (where Mes = 2,4,6-Me3C6H2; Dipp = 2,6-Pr(i)2C6H3) with n-BuLi in hexane, followed by the crystallization from hexane-THF mixture afforded the corresponding lithium 1,3,5-triazapentadienyl complexes as their THF solvates. X-Ray crystallographic analyses revealed that [N{(C3F7)C(Mes)N}2]Li(THF)2 and [N{(C3F7)C(Dipp)N}2]Li(THF) are monomeric in the solid state. [N{(C3F7)C(Mes)N}2]Li(THF)2 has a four-coordinate lithium center with a distorted tetrahedral geometry, and features a boat-shaped C2N3Li metallacycle. [N{(C3F7)C(Dipp)N}2]Li(THF) has a three-coordinate lithium atom and a planar, U-shaped C2N3 ligand backbone. The synthesis, solid-state structure, and 1H and 19F NMR spectroscopic details of [N{(C3F7)C(Mes)N}2]H are also reported.     

Synthesis and redox behaviour of the chalcogenocarbonyl dianions [(E)C(PPh(2)S)(2)](2-): formation and structures of chalcogen-chalcogen bonded dimers and a novel selone

The lithium salts of the chalcogenocarbonyl dianions [(E)C(PPh₂S)₂]^2? (E=S ( 4 b ), Se ( 4 c )) were produced through the reactions between Li₂[C(PPh₂S)₂] and elemental chalcogens in the presence of tetramethylethylenediamine (TMEDA). The solid‐state structure of {[Li(TMEDA)]₂[(Se)C(PPh₂S)₂]}—[{Li(TMEDA)}₂ 4 c ]—was shown to be bicyclic with the Li⁺ cations bis‐S,Se‐chelated by the dianionic ligand. One‐electron oxidation of the dianions 4 b and 4 c with iodine afforded the diamagnetic complexes {[Li(TMEDA)]₂[(SPh₂P)₂CEEC(PPh₂S)₂]} ([Li(TMEDA)]₂ 7 b (E=S), [Li(TMEDA)]₂ 7 c (E=Se)), which are formally dimers of the radical anions [(E)C(PPh₂S)₂]^{? .} (E=S ( 5 b ), Se ( 5 c )) with elongated central E? E bonds. Two‐electron oxidation of the selenium‐containing dianion 4 c with I₂ yielded the LiI adduct of a neutral selone {[Li(TMEDA)][I(Se)C(PPh₂S)₂]}—[{LiI(TMEDA)} 6 c ]—whereas the analogous reaction with 4 b resulted in the formation of 7 b followed by protonation to give {[Li(TMEDA)][(SPh₂P)₂CSS(H)C(PPh₂S)₂]}—[Li(TMEDA)] 8 b . Attempts to identify the transient radicals 5 b and 5 c by EPR spectroscopy in conjunction with DFT calculations of the electronic structures of these paramagnetic species and their dimers are also described. The crystal structures of [{Li(TMEDA)}₂ 4 c ], [{LiI(TMEDA)} 6 c ] ? C₇H₈, [Li(TMEDA)]₂ 7 b? (CH₂Cl₂)_0.33, [Li(THF)₂]₂ 7 b , [Li(TMEDA)]₂ 7 c , [Li(TMEDA)] 8 b? (CH₂Cl₂)₂ and [Li([12]crown‐4)₂] 8 b were determined and salient structural features are discussed.     

Phosphonium-borate zwitterions, anionic phosphines, and dianionic phosphonium-dialkoxides via tetrahydrofuran ring-opening reactions

Sterically demanding secondary phosphines and phosphides react with (THF)B(C(6)F(5))(3) (THF = tetrahydrofuran) to give the THF ring-opened compounds [R(2)PHC(4)H(8)OB(C(6)F(5))(3)] and [Mes(2)PC(4)H(8)OB(C(6)F(5))(3)Li(THF)(2)] (Mes = C(6)H(2)Me-2,4,6). These reactions also occur consecutively to give the double THF ring-opened compounds [Mes(2)P(C(4)H(8)OB(C(6)F(5))(3))(2)][Li(THF)(4)] and [t-Bu(2)P(C(4)H(8)OB(C(6)F(5))(3))(2)Li].     

Silyl‐Phosphino‐Carbene Complexes of Uranium(IV)

Unprecedented silyl‐phosphino‐carbene complexes of uranium(IV) are presented, where before all covalent actinide–carbon double bonds were stabilised by phosphorus(V) substituents or restricted to matrix isolation experiments. Conversion of [U(BIPM^TMS)(Cl)(μ‐Cl)₂Li(THF)₂] ( 1 , BIPM^TMS=C(PPh₂NSiMe₃)₂) into [U(BIPM^TMS)(Cl){CH(Ph)(SiMe₃)}] ( 2 ), and addition of [Li{CH(SiMe₃)(PPh₂)}(THF)]/Me₂NCH₂CH₂NMe₂ (TMEDA) gave [U{C(SiMe₃)(PPh₂)}(BIPM^TMS)(μ‐Cl)Li(TMEDA)(μ‐TMEDA)_0.5]₂ ( 3 ) by α‐hydrogen abstraction. Addition of 2,2,2‐cryptand or two equivalents of 4‐N,N‐dimethylaminopyridine (DMAP) to 3 gave [U{C(SiMe₃)(PPh₂)}(BIPM^TMS)(Cl)][Li(2,2,2‐cryptand)] ( 4 ) or [U{C(SiMe₃)(PPh₂)}(BIPM^TMS)(DMAP)₂] ( 5 ). The characterisation data for 3 – 5 suggest that whilst there is evidence for 3‐centre P?C?U π‐bonding character, the U=C double bond component is dominant in each case. These U=C bonds are the closest to a true uranium alkylidene yet outside of matrix isolation experiments.     

Synthesis, NMR characterisation and X-ray structures of mixed chalcogenido PNP ligands containing tellurium: crystal structures of SeiPr2PNP(H)iPr2 and [NaN(EPiPr2)2]infinity (E = Se, Te)

Reaction of HN(PiPr2)2 with one equivalent of selenium in hexane at room temperature yields the monoselenide as the P-H tautomer Se=PiPr2-N=P(H)iPr2 (2b). Deprotonation of 2b with n butyllithium in the presence of TMEDA at -78 degrees C followed by addition of tellurium produces the air-sensitive, mixed chalcogenido complex [(TMEDA)Li(SePiPr2)(TePiPr2)N] (8Li) in >97% purity after recrystallisation. Similarly, deprotonation of Te=PiPr2-N=P(H)iPr2 (2c), followed by addition of sulfur, gives the sulfur analogue [(TMEDA)Li(SPiPr2)(TePiPr2)N] (7Li) in >99% purity. The symmetrical complexes [(TMEDA)Li(SePiPr2)2N] (4Li) and [(TMEDA)Li(TePiPr2)2N] (5Li) are produced by similar methods. Compounds 2b, 4Li, 5Li, 7Li and 8Li were characterised in solution by multinuclear (1H, 31P, 77Se and 125Te) NMR spectroscopy and their solid-state structures were determined by X-ray crystallography. The X-ray crystal structures of the polymeric chains [NaN(EPiPr2)2]infinity (4Na, E = Se and 5Na, E = Te) are also reported.     

The formation of mesitylphosphine and dimesitylphosphine in the reaction of organonickel σ-complex [NiBr(Mes)(bpy)] (Mes = 2,4,6-trimethylphenyl,bpy = 2,2′-bipyridine) with phosphine PH3

Abstract

The reactivity of the previously reported organonickel σ-complex [NiBr(Mes)(bpy)], where Mes = 2,4,6-trimethylphenyl, bpy = 2,2′-bipyridine, toward phosphine PH₃ was investigated. The reaction leads to primary mesitylphosphine MesPH₂ as the main product and dimesitylphosphine Mes₂PH as secondary product with the nickel complex as transmetalating agent. The formed MesPH₂ reacts with an excess of the complex giving Mes₂PH as the major product.     

Structural diversity in solvated lithium aryloxides. Syntheses, characterization, and structures of [Li(OAr)(THF)x]n and [Li(OAr)(py)x]2 complexes where OAr = OC6H5, OC6H4(2-Me), OC6H3(2,6-(Me))2, OC6H4(2-Pr(i)), OC6H3(2,6-Pr(i)))2, OC6h4(2-Bu(t)), OC6H3(2,6-Bu(t)))2

A series of sterically varied aryl alcohols H-OAr [OAr = OC6H5 (OPh), OC6H4(2-Me) (oMP), OC6H3(2,6-(Me))2 (DMP), OC6H4(2-Pr(i)) (oPP), OC6H3(2,6-(Pr(i)))2 (DIP), OC6H4(2-Bu(t)) (oBP), OC6H3(2,6-(Bu(t)))2 (DBP); Me = CH3, Pr(i) = CHMe2, and Bu(t) = CMe3] were reacted with LiN(SiMe3)2 in a Lewis basic solvent [tetrahydrofuran (THF) or pyridine (py)] to generate the appropriate "Li(OAr)(solv)x". In the presence of THF, the OPh derivative was previously identified as the hexagonal prismatic complex [Li(OPh)(THF)]6; however, the structure isolated from the above route proved to be the tetranuclear species [Li(OPh)(THF)]4 (1). The other "Li(OAr)(THF)x" products isolated were characterized by single-crystal X-ray diffraction as [Li(OAr)(THF)]4 [OAr = oMP (2), DMP (3), oPP (4)], [Li(DIP)(THF)]3 (5), [Li(oBP)(THF)2]2, (6), and [Li(DBP)(THF)]2, (7). The tetranuclear species (1-4) consist of symmetric cubes of alternating tetrahedral Li and pyramidal O atoms, with terminal THF solvent molecules bound to each metal center. The trinuclear species 5 consists of a six-membered ring of alternating trigonal planar Li and bridging O atoms, with one THF solvent molecule bound to each metal center. Compound 6 possesses two Li atoms that adopt tetrahedral geometries involving two bridging oBP and two terminal THF ligands. The structure of 7 was identical to the previously reported [Li(DBP)(THF)]2 species, but different unit cell parameters were observed. Compound 7 varies from 6 in that only one solvent molecule is bound to each Li metal center of 7 because of the steric bulk of the DBP ligand. In contrast to the structurally diverse THF adducts, when py was used as the solvent, the appropriate "Li(OAr)(py)x" complexes were isolated as [Li(OAr)(py)2]2 (OAr = OPh (8), oMP (9), DMP (10), oPP (11), DIP (12), oBP (13)) and [Li(DBP)(py)]2 (14). Compounds 8-13 adopt a dinuclear, edge-shared tetrahedral complex. For 14, because of the steric crowding of the DBP ligand, only one py is coordinated, yielding a dinuclear fused trigonal planar arrangement. Two additional structure types were also characterized for the DIP ligand: [Li(DIP)(H-DIP)(py)]2 (12b) and [Li2(DIP)2(py)3] (12c). Multinuclear (6,7Li and 13C) solid-state MAS NMR spectroscopic studies indicate that the bulk powder possesses several Li environments for "transitional ligands" of the THF complexes; however, the py adducts possess only one Li environment, which is consistent with the solid-state structures. Solution NMR studies indicate that "transitional" compounds of the THF precursors display multiple species in solution whereas the py adducts display only one lithium environment.     

Different transmetallation behaviour of [M(P4HR4)] salts toward rhodium(I) and copper(I) (M = Na, K; R = Ph, Mes; Mes = 2,4,6-Me3C6H2)

[K(2)(P(4)Mes(4))] (1) or [Na(2)(THF)(4)(P(4)Mes(4))] (2) (Mes = 2,4,6-Me(3)C(6)H(2)) reacts with one equivalent of HCl and subsequently with 0.5 equivalents of [{RhCl(cod)}(2)] (cod = 1,5-cyclooctadiene) to give a mixture of rhodium complexes, from which [Rh(P(4)HMes(4))(cod)] (3) and the secondary product [Rh(2)(micro-P(2)HMes(2))(mu-PHMes)(cod)(2)] (4) were isolated and characterised by X-ray diffraction studies. Alternatively, the reaction of [K(2)(P(4)Ph(4))] (5) or [Na(2)(THF)(5)(P(4)Ph(4))] (6) with one equivalent of HCl and subsequently with one equivalent of [CuCl(PCyp(3))(2)] (Cyp = cyclo-C(5)H(9)) gave the complex [Cu(4)(P(4)Ph(4))(2)(PH(2)Ph)(2)(PCyp(3))(2)] (7), presumably via disproportionation of the monoanion (P(4)HPh(4))(-).     

Solution behavior and structural properties of Cu(I) complexes featuring m-terphenyl isocyanides

The synthesis of the m-terphenyl isocyanide ligand CNAr (Mes2) (Mes = 2,4,6-Me 3C 6H 2) is described. Isocyanide CNAr (Mes2) readily functions as a sterically encumbering supporting unit for several Cu(I) halide and pseudo halide fragments, fostering in some cases rare structural motifs. Combination of equimolar quantities of CNAr (Mes2) and CuX (X = Cl, Br and I) in tetrahydrofuran (THF) solution results in the formation of the bridging halide complexes (mu-X) 2[Cu(THF)(CNAr (Mes2))] 2. Addition of CNAr (Mes2) to cuprous chloride in a 2:1 molar ratio generates the complex ClCu(CNAr (Mes2)) 2 in a straightforward manner. Single-crystal X-ray diffraction has revealed ClCu(CNAr (Mes2)) 2 to exist as a three-coordinate monomer in the solid state. As determined by solution (1)H NMR and FTIR spectroscopic studies, monomer ClCu(CNAr (Mes2)) 2 resists tight binding of a third CNAr (Mes2) unit, resulting in rapid isocyanide exchange. Contrastingly, addition of 3 equiv of CNAr (Mes2) to cuprous iodide readily affords the tris-isocyanide species, ICu(CNAr (Mes2)) 3, as determined by X-ray diffraction. Similar coordination behavior is observed in the tris-isocyanide salt [(THF)Cu(CNAr (Mes2)) 3]OTf (OTf = O 3SCF 3), which is generated upon treatment of (C 6H 6)[Cu(OTf)] 2 with 6 equiv of CNAr (Mes2) in THF. The disparate coordination behavior of the [CuCl] fragment relative to both [CuI] and [CuOTf] is rationalized in terms of structure and Lewis acidity of the Cu-containing fragments. The putative triflate species [Cu(CNAr (Mes2)) 3]OTf itself serves as a good Lewis acid and is found to weakly bind C 6H 6 in an eta (1)- C manner in the solid-state. Density Functional Theory is used to describe the bonding and energetics of the eta (1)- C Cu-C 6H 6 interaction.     

Synthese,Struktur und magnetische Eigenschaften von [CrCl(μ-Cl)(TMEDA)]2

Synthesis, Structure, and Magnetic Properties of [CrCl(-μCl)(TMEDA)]₂ The title complex [CrCl(μ-Cl)(TMEDA)]₂ ( 1 ) is obtained in an equimolar reaction of CrCl₂(THF) with TMEDA in high yield. 1 crystallises in the monoclinic space group P2₁/c with a = 843.2(2), b = 1 109.(2), c = 1 147.4(3) pm, β = 102.99(2)° and Z = 2. The molecular structure of 1 contains two, slightly distorted quadratic pyramidal CrL₅-subunits, which are linked via two unsymmetrical Cl-bridges. The μ-Cl-functions take the apical position of one and a basal position of the second CrL₅-unit, wherein the apical Cr–Cl bond (277.6(1) pm) is destinctly longer than the basal Cr–Cl bond (240.6(1) pm). The terminal Cr–Cl bond is still shorter (237.5(1) pm). The Cr…Cr distance is far beyond any bonding interaction. This is confirmed by means of magnetic susceptibility measurements, which show four unpaired electrons per Cr centre; however, a small antiferromagnetic coupling of J/k = ?7.3 K can be calculated. This coupling is suggested to be originated by a 90°-σ-superexchange via the asymmetric μ-Cl functions.     

Reaktionen von Nitrilen mit tBuAsLi2

Reactions of Nitriles with ^tBuAsLi₂ ^tBuAsLi₂ reacts with the α‐acidic nitrile malonicaciddinitrile in THF/TMEDA under deprotonation and formation of the coordination polymer [{Li(TMEDA}{HC(CN)₂}]_n ( 1 ). The more base‐stable PhCN gives with ^tBuAsLi₂ under aromatization the salt [Li(Diglyme)₂][Li(TMEDA){As[NC(Ph)NC(Ph)]}₂] ( 2 ), containing a diazaarsolide. 1 and 2 were characterized by NMR and vibrational spectroscopy, mass spectrometry and X‐ray analyses. According to that, 1 contains in the solid state infinite helical chains of cations and anions, running along [010]. 2 consists of distorted octahedrally coordinated Li⁺ ion, [Li(diglyme)₂]⁺, and the complex anion [Li(TMEDA){As[NC(Ph)NC(Ph)]}₂]^‐ with a distorted tetrahedrally environment of the Li⁺ ion.     

Co-complexes of ortho-dilithiated thiophenol or 2-trimethylsilylthiophenol with lithiated TMEDA molecules: synthesis, crystal structures and theoretical studies (TMEDA = N,N,N',N'-tetramethylethylenediamine)

When an excess of nBuLi was used in the ortho-dilithiation of thiophenol or 2-trimethylsilylthiophenol in the presence of TMEDA (TMEDA = N,N,N',N'-tetramethylethylenediamine), deprotonation of TMEDA occurred and crystals of [Li3{(2-S-C6H4)(CH2MeNCH2CH2NMe2)(TMEDA)}]2 (1) or [Li4{(2-S-3-SiMe3-C6H3)(CH2MeNCH2CH2NMe2)2(TMEDA)}] (2) were obtained. Molecular orbital calculations on gas-phase 1 and 2 at the DFT B3LYP/6-31G(d) level reproduce the experimental structures fairly well. In spite of the short Li...Li distances, total electron density representations do not support the existence of Li...Li interactions.     

Komplexchemie P-reicher Phosphane und Silylphosphane. XI [1]. Bildung,Reaktionen und Strukturen von Chromcarbonylkomplexen aus Reaktionen von Li(THF)2[η2-(tBu2P)2P] mit Cr(CO)5 · THF und Cr(CO)4 · NBD

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. XI. Formation, Reactions, and Structures of Chromium Carbonyl Complexes from Reactions of Li(THF)₂[η₂-(^tBu₂P)₂P] with Cr(CO)₅ · THF and Cr(CO)₄ · NBD Reactions of Li(THF)₂[η²-(^tBu₂P)₂P] 1 with Cr(CO)₅ · THF yield Li(THF)₂Et₂O[Cr(CO)₄{η²-(^tBu₂P)₂P}η¹-Cr(CO)₅] 2 and the compounds [Cr(CO)₄{η²-(^tBu₂P)₂PH}] 3 , [Cr(CO)₅{η¹-(^tBu₂P)₂PH}] 4 , (^tBu₂P)₂PH 5 and ^tBu₂PH · Cr(CO)₅ 6 . The formation of 3, 4, 5 and 6 is due to byproducts coming from the synthesis of 1. 2 reacts with CH₃COOH under formation of 3 . After addition of 12-crown-4 1 with NBD · Cr(CO)₄ in THF forms Li(12-crown-4)₂[Cr(CO)₄-{η²-(^tBu₂P)₂P}] 7 (yellow crystals). 7 reacts with CH₃COOH to 3 – which regenerates 7 with LiBu – with Cr(CO)₅THF to compound 2 , with NBD · Cr(CO)₄ in THF to 2 and 3 (ratio 1 : 1). With EtBr, 7 forms [Cr(CO)₄{η²-(^tBu₂P)₂PEt}] 8 , and [Cr(CO)₄{η²-(^tBu₂P)₂PBr}] 9 with BrCH₂? CH₂Br. The compounds were characterized by means of ¹H, ¹³C, ³¹P, ⁷Li NMR spectroscopy, IR spectroscopy, elementary analysis, mass spectra, and 2, 3 and 4 additionally by means of X-ray diffraction analysis. 2 crystallizes in the space group P1 with 2 formula units in the elementary cell; a = 10.137(9), b = 15.295(12), c = 15.897(14) Å; α = 101.82(7), β = 91.65(7), γ = 98.99(7)°; 3 crystallizes in the space group P2_t/n with 4 molecules in the elementary unit; a = 11.914(6), b = 15.217(10), c = 14.534(10) Å; α = 90, β = 103.56(5), γ = 90°. 4 : space group P1 with 2 molecules in the elementary unit; a = 8.844(4), b = 12.291(6), c = 14.411(7) Å, α = 66.55(2), β = 89.27(2), γ = 71.44(2)°.     

Deprotonation of a Seemingly Hydridic Diborane(6) To Build a B−B Bond

Deprotonation of the doubly arylene‐bridged diborane(6) derivative 1 H₂ with (Me₃Si)₃CLi or (Me₃Si)₂NK gives the B−B σ‐bonded species M[ 1 H] in essentially quantitative yields (THF, room temperature; M=Li, K, arylene=4,4′‐di‐tert‐butyl‐2,2′‐biphenylylene). With nBuLi as the base, the yield of Li[ 1 H] drops to 20 % and the 1,1‐bis(9‐borafluorenyl)butane Li[ 2 H] is formed as a side product (30 %). In addition to the 1,1‐butanediyl fragment, the two boron atoms of Li[ 2 H] are linked by a μ‐H bridge. In the closely related molecule Li[ 3 H], the corresponding μ‐H atom can be abstracted with (Me₃Si)₃CLi to afford the B−B‐bonded conjugated base Li₂[ 3 ] (THF, 150 °C; 15 %). Li[ 1 H] and Li[ 2 H] were characterized by NMR spectroscopy and X‐ray crystallography.     

Low-valent chemistry of cobalt amide. Synthesis and structural characterization of cobalt(II) amido, aryloxide, and thiolate compounds

The binuclear cobalt(II) amide complex [(CoL2)2-(TMEDA)] (1) [L = N(Si(t)BuMe2)(2-C5H3N-6-Me); TMEDA = Me2NCH2CH2NMe2] has been synthesized by the reaction of anhydrous CoCl2 with 2 equiv of [Li(L)(TMEDA)]. X-ray crystallography revealed that complex 1 consists of two [CoL2] units linked by one TMEDA ligand molecule, which binds in an unusual N,N'-bridging mode. Protolysis of 1 with the bulky phenol Ar(Me)OH (Ar(Me) = 2,6-(t)Bu2-4-MeC6H2) and thiophenol ArSH (Ar = 2,4,6-(t)Bu3C6H2) gives the neutral monomeric cobalt(II) bis(aryloxide) [Co(OAr(Me))2(TMEDA)] (2) and dithiolate [Co(SAr)2(TMEDA)] (3), respectively. Complexes 1-3 have been characterized by mass spectrometry, microanalysis, magnetic moment, and melting-point measurements, in addition to X-ray crystallography.     

Lithiation of tris(alkyl- and arylamido)orthophosphates EP[N(H)R]3 (E = O,S, Se): imido substituent effects and P=E bond cleavage

In the solid state, OP[N(H)Me](3) (1a) and OP[N(H)(t)Bu](3) (1b) have hydrogen-bonded structures that exhibit three-dimensional and one-dimensional arrays, respectively. The lithiation of 1b with 1 equiv of (n)BuLi generates the trimeric monolithiated complex (THF)[LiOP(N(t)Bu)[N(H)(t)Bu](2)](3) (4), whereas reaction with an excess of (n)BuLi produces the dimeric dilithium complex [(THF)(2)Li(2)OP(N(t)Bu)(2)[N(H)(t)Bu]](2) (5). Complex 4 contains a Li(2)O(2) ring in an open-ladder structure, whereas 5 embraces a central Li(2)O(2) ring in a closed-ladder arrangement. Investigations of the lithiation of tris(alkyl or arylamido)thiophosphates, SP[N(H)R](3) (2a, R = (i)Pr; 2b, R = (t)Bu; 2c, R = p-tol) with (n)BuLi reveal interesting imido substituent effects. For the alkyl derivatives, only mono- or dilithiation is observed. In the case of R = (t)Bu, lithiation is accompanied by P-S bond cleavage to give the dilithiated cyclodiphosph(V/V)azane [(THF)(2)Li(2)[((t)BuN)(2)P(micro-N(t)Bu)(2)P(N(t)Bu)(2)]] (9). Trilithiation occurs for the triaryl derivatives EP[N(H)Ar](3) (E = S, Ar = p-tolyl; E = Se, Ar = Ph), as demonstrated by the preparation of [(THF)(4)Li(3)[SP(Np-tol)(3)]](2) (10) and [(THF)(4)Li(3)[SeP(NPh)(3)]](2) (11), which are accompanied by the formation of small amounts of 10.[LiOH(THF)](2) and 11.Li(2)Se(2)(THF)(2), respectively.     

Structural and magnetic studies of the tris(cyclopentadienyl)manganese(II) "paddle-wheel" anions [Cp(3-n)(MeCp)(n)Mn](-) (n=0-3, MeCp=C(5)H(4)CH(3), Cp=C(5)H(5))

The ion-contact complexes [{(eta(5)-Cp)(2)Mn(eta(2):eta(5)-Cp)K}(3)]x0.5 THF (1x0.5 THF) and [{(eta(2)-Cp)(2)(eta(2);eta(5)-MeCp)MnK(thf)}]x2 THF (2x2 THF) and ion-separated complexes [Mg(thf)(6)][(eta(2)-Cp)(3)Mn](2) (3), [Mg(thf)(6)][(eta(2)-Cp)(eta(2)-MeCp)(2)Mn)](2)x0.5 THF (4x0.5 THF), [Mg(thf)(6)][(eta(2)-MeCp)(3)Mn)](2)x0.5 THF (5x0.5 THF) and [Li([12]crown-4)](5)[(eta-Cp)(3)Mn](5) (6) (Cp=C(5)H(5), CpMe=C(5)H(4)CH(3)), have been prepared and structurally characterised. The effects of varying the Cp and CpMe ligands in complexes 1-5 have been probed by variable-temperature magnetic susceptibility measurements and EPR spectroscopic studies.     

Alkali Metal Bis(o-anisyl)phosphides: Characterization of MP(C(6)H(4)OMe-o)(2) (M = Li, Na) and Crystal Structure of a Sodium Secondary Organophosphide

Lithium bis(o-anisyl)phosphide (1)may be prepared by reaction of n-BuLi with bis(o-anisyl)phosphine in THF or toluene; sodium bis(o-anisyl)phosphide (2) is prepared by reaction of sodium with tris(o-anisyl)phosphine in liquid ammonia/THF; both compounds are isolated as unsolvated solids. 1 decomposes quantitatively in THF to give tetrakis(o-anisyl)diphosphine (4); 2 decomposes in THF to give a mixture containing 4 and bis(o-anisyl)phosphine. Addition of diglyme to 2 gives [Na{&mgr;-P(C(6)H(4)OMe-o)(2)}(MeO(CH(2)CH(2)O)(2)Me)](2) (2a), which has been characterized by single-crystal X-ray diffraction. Each Na atom in 2a is 6-coordinate, being bonded to two P atoms, three diglyme O atoms, and one O atom from an o-anisyl group. Crystal data: monoclinic, P2(1)/n, a = 14.549(4) ?, b = 18.555(6) ?, c = 15.846(4) ?, beta = 91.07(2) degrees, Z = 4, final R = 0.041, R(w) = 0.053.     

Divalent lanthanide complexes supported by the bridged bis(amidinates) L Me3SiN(Ph)CN(CH2)3NC(Ph)NSiMe3]: synthesis, molecular structures and one-electron-transfer reactions

Metathesis reactions of YbI(2) with Li(2)L (L = Me(3)SiN(Ph)CN(CH(2))(3)NC(Ph)NSiMe(3)) in THF at a molar ratio of 1:1 and 1:2 both afforded the Yb(II) iodide complex [{YbI(DME)(2)}(2)(μ(2)-L)] (1), which was structurally characterized to be a dinuclear Yb(II) complex with a bridged L ligand. Treatment of EuI(2) with Li(2)L did not afford the analogous [{EuI(DME)(2)}(2)(μ(2)-L)], or another isolable Eu(II) complex, but the hexanuclear heterobimetallic cluster [{Li(DME)(3)}(+)](2)[{(EuI)(2)(μ(2)-I)(2)(μ(3)-L)(2)(Li)(4)}(μ(6)-O)](2-) (2) was isolated as a byproduct in a trace yield. The rational synthesis of cluster 2 could be realized by the reaction of EuI(2) with Li(2)L and H(2)O in a molar ratio of 1:1.5:0.5. The reduction reaction of LLnCl(THF)(2) (Ln = Yb and Eu) with Na/K alloy in THF gave the corresponding Ln(II) complexes [Yb(3)(μ(2)-L)(3)] (3) and [Eu(μ(2)-L)(THF)](2) (4) in good yields. An X-ray crystal structure analysis revealed that each L in complex 3 might adopt a chelating ligand bonding to one Yb atom and each Yb atom coordinates to an additional amidinate group of the other L and acts as a bridging link to assemble a macrocyclic structure. Complex 4 is a dimer in which the two monomers [Eu(μ(2)-L)(THF)] are connected by two μ(2)-amidinate groups from the two L ligands. Complex 3 reacted with CyN═C═NCy and diazabutadienes [2,6-(i)Pr(2)C(6)H(3)N═CRCR═NC(6)H(3)(i)Pr(2)-2,6] (R═H, CH(3)) (DAD) as a one-electron reducing agent to afford the corresponding Yb(III) derivatives: the complex with an oxalamidinate ligand [LYb{(NCy)(2)CC(NCy)(2)}YbL] (5) and the complexes containing a diazabutadiene radical anion [LYb((i)Pr(2)C(6)H(3)NCRCRNC(6)H(3)(i)Pr(2))] (R = H (6), R = CH(3) (7)). Complexes 5-7 were confirmed by an X-ray structure determination.     

Synthese und Kristallstrukturen von [Li(thf)4]2[Bi4I14(thf)2], [Li(thf)4]4[Bi5I19] und (Ph4P)4[Bi6I22]

Synthesis and Crystal Structure of [Li(thf)₄]₂[Bi₄I₁₄(thf)₂], [Li(thf)₄]₄[Bi₅I₁₉], and (Ph₄P)₄[Bi₆I₂₂] Solutions of BiI₃ in THF or methanol react with MI (M = Li, Na) to form polynuclear iodo complexes of bismuth. The syntheses and results of X-ray structure analyses of compounds [Li(thf)₄]₂[Bi₄I₁₄(thf)₂], [Li(thf)₄]₄[Bi₅I₁₉], [Na(thf)₆]₄[Bi₆I₂₂] and (Ph₄P)₄[Bi₆I₂₂] are described. The anions of these compounds consist of edge-sharing BiI₆ and BiI₅(thf) octahedra. The Bi atoms lie in a plane and are coordinated by bridging and terminal I atoms and by THF ligands in a distorted octahedral fashion. [Li(thf)₄]₂[Bi₄I₁₄(thf)₂]: Space group P1 (No. 2), a = 1 159.9(6), b = 1 364.6(7), c = 1 426.5(7) pm, α = 114.05(3), β = 90.01(3), γ = 100.62(3)°. [Li(thf)₄]₄[Bi₅I₁₉]: Space group P2₁/n (No. 14), a = 1 653.0(9), b = 4 350(4), c = 1 836.3(13) pm, β = 114.70(4)°. [Na(thf)₆]₄[Bi₆I₂₂]: Space group P2₁/n (No. 14), a = 1 636.4(3), b = 2 926.7(7), c = 1 845.8(4) pm, β = 111.42(2)°. (Ph₄P)₄[Bi₆I₂₂]: Space group P1 (No. 2), a = 1 368.6(7), b = 1 508.1(9), c = 1 684.9(8) pm, α = 98.28(4), β = 95.13(4), γ = 109.48(4)°.