The reactions of 2-[(dimethylamino)methyl]phenylcopper and -lithium tetramer with cuprous and cupric halides

2-[(Dimethylamino)methyl]phenylcopper tetramer (R₄Cu₄) forms a red $\text{1}\text{1}$ complex (RCu - CuBr)_n with cuprous bromide. The $\text{1}\text{1}$ interaction of 2-[(dimethylamino)methyl]phenylcopper with cupric halides results in the formation of the dimer RR, the 2-halo-substituted benzylamine R—Halide and minor amounts of N,N-dimethylbenzylamine RH. The formation of these products can be explained on the basis of an intramolecular electron-transfer redox reaction taking place in innersphere activated complexes of the type R₄Cu₃Cu - - - X - - - Cu^IIX(Cu^IIX₂)_n-1. The course of the metathesis reaction of 2-[(dimethylamino)methyl]phenyllithium with cuprous bromide depends on the order of addition of the reactants. Reversed addition (RLi to CuBr) results in the formation of an inseparable mixture of complexes of the type (RCu)_x- (CuBr)_y. Upon addition of CuBr to RLi the uncomplexed organocopper compound R₄Cu₄ is formed.     

Group IB organometallic chemistry: XXIX. Synthetic and structural aspects of polynuclear arylcopperlithium compounds Ar4Cu2Li2 (“arylcuprates”) and interaggregate exchange phenomena in Ar4Cu4/Ar4Li4/Ar4Cu2Li2 systems

The thermally stable arylmetal-IB-lithium compounds (2-Me₂NCHZC₆H₄)₄M₂Li₂ (M = Cu, Ag or Au; Z = H or Me) and (2-Me₂NC₆H₄)₄M₂Li₂ have been prepared by a $\text{2}\text{1}$ molar reaction of the aryllithium compounds with the corresponding metal-IB halide (Cu or Ag) or metal-lB halide phosphine complex (BrAuPPh₃). These tetranuclear complexes were also made by an interaggregate exchange reaction of the pure arylmetal-IB clusters with the aryllithium compound.The structure of these compounds in solution consists of aryl groups bridging one metal-lB and one lithium atom of a trans M₂Li₂ core. The four built-in ligands coordinate to lithium resulting in two-coordination at M and four-coordination at Li. These conclusions were based on ¹H and ¹³C NMR spectroscopic data (J(AgC(1)), J(LiC(1)) of solutions of these tetranuclear compounds as well as on the ¹⁹⁷Au Mössbauer data of solid (2-Me₂NC₆H₄)₄Au₂Li₂ (IS 5.65 mm/s and QS 12.01 mm/s).The interaggregate exchange between the tetranuclear species is discussed in terms of an associative mechanism involving formation of an octanuclear intermediate in which the aryl groups can migrate via (3c-2e)edge-(2c-2e)corner(3c-2e)edge movements without M₂Ar bond cleavage.Some aspects of the organic reactions in which organocuprates are involved as intermediates are discussed in terms of the novel structural information.     

The crystal structure,equilibrium and spectroscopic studies of bis(dialkyldithiocarbamate) copper(II) complexes [Cu2(R2dtc)4] (dtc=dithiocarbamate)

Four copper(II) complexes of bis(dialkyldithiocarbamate) [Cd(R₂dtc)₂] (R=Me, Et, Pr, i-Pr; dtc=dithiocarbamate) have been prepared and characterized by elemental analysis, IR and ESR spectra studies. Their equilibrium constants (K), determined by a UV–vis spectrometry in EtOH, were influenced by the alkyl groups in the following order: i-Pr>n-Pr≈Et>Me. The single crystal structures of complex [Cu₂(R₂dtc)₄] have been determined using X-ray diffraction methods. The compounds [Cu₂(Et₂dtc)₄] and [Cu₂(Pr₂dtc)₄] are built of centrosymmetric neutral dimeric [Cu₂(R₂dtc)₄] entities. The copper atom lies in a distorted square–pyramidal environment. The four equatorial donors are two bidentate chelate sulfur atoms from two dtc ligands. One of the sulfur atoms from the third dtc ligand acts as a bridging ligand occupying the apical position of the symmetry-related copper atom in the dimer structure, which is viewed as two edge-sharing distorted square–pyramids. The structure of [Cu₂(i-Pr₂dtc)₄] is square planar with an exactly planar CuS₄ unit and nearly planar NCS₂ moieties. The Cu–S distances shows small decreases along the series n-Pr>Et>i-Pr, the biggest change being for the diisopropyl complex. The alkyl substituents at the nitrogen atom affect their coordination number and Cu⋯Cu distance. In the solid, [Cu₂(n-Pr₂dtc)₄] has the shortest Cu⋯Cu distance and [Cu(i-Pr₂dtc)₂] has the longest one.     

Cluster condensation reactions. The synthesis and crystal and molecular structure of Os6(CO)14(μ2-PPh2)2(μ3-S)3(μ4-S)

Thermal degradation of the cluster compound Os₃(CO)₈(PPh₂H)(μ₃-S)₂ (I) at 125°C leads to decarbonylation and formation of the new ligand bridged hexanuclear cluster Os₆(CO)₁₄(μ-PPh₂)₂(μ₃-S)₃(μ₄-S) (II) in 11% yield. Space Group: P$\text{1}$, No. 2, a 10.427(5), b 13.552(3), c 17.919(3) Å, α 84.87(2), β 75.41(3), γ 78.43(3)°, V 2399(2) ųZ = 2, _?calc 2.82 g cm^?3. The structure was solved by the heavy atom method and refined (3223 reflections) to the final residuals R = 0.042 and R_w = 0.036. The molecule consists of two sulfido bridged open triosmium clusters which are linked by a bridging sulfido ligand and a bridging diphenylphosphino ligand.     

A Novel Octahedral Hexasilver（I） Cluster： Ag[SSCN（n—C4H9）2]6

The first crystal structural report of a AgDTC complex (DTC-dialkyldithiocarbamate,R=n-butyl)presented in this paper shows that it is a hexanuclear species.The structural arrangement for the DDP(dialkyldithiophosphate)ligands is different from that of Cu6(DDP)6,but is the same as that of Ag6-[SSP(O-i-Pr)2]6.     

Novel Copper(I) Clusters with 2‐(Diphenylphosphanyl)anilide Ligands. Synthesis and Crystal Structures of [Cu6X2(NHR)4] (X = Cl,Br, I; R = C6H4‐2‐PPh2)

Treatment of copper(I) halides CuX (X = Cl, Br, I) with lithium 2‐(diphenylphosphanyl)anilide [Li(HL)] in THF led to the formation of hexanuclear copper(I) complexes [Cu₆X₂(HL)₄] [X = Cl ( 1 ), Br ( 2 ), I ( 3 )]. In compounds 1 – 3 , the copper atoms are in a distorted octahedral arrangement and the amide ligands adopt a μ₃‐κP,κ²N bridging mode. Additionally there are two μ₂‐bridging halide ligands. Each of the [Cu₆X₂(HL)₄] clusters comprises two copper atoms, which are surrounded by two amide nitrogen atoms in an almost linear coordination [Cu–N: 186.2(3)–188.0(3) pm] and four copper atoms, which are connected to an amide N atom, a P atom, and a halogen atom in a distorted trigonal planar fashion [Cu–N: 199.6(3)–202.3(3) pm)].     

Group IB organometallic chemistry: XXXV. Crystal and molecular structure of [Cu4(4-MeC6H4)-MeC-C(C6H4NMe2-2)2(C6H4NMe2-2)2], a tetranuclear organocopper compound containing bridging alkenyl and aryl groups

The crystal and molecular structure of the title compound has been determined by a single crystal X-ray diffraction study using standard Patterson and Fourier methods. The structure was refined by a block-diagonal least-square procedure to a finalR value of 0.16 for 3454 reflections. Crystals are monoclinic, space groupP2₁/c, witha 14.007(5), b 12.224(5), c 28.358(8)A?, β 99.60(1)°, andZ - 4.The molecule consists of a central rhombus-type core of copper atoms to which the alkenyl and aryl groups are bound in a bridging fashion (two electron-three center bonding). The two alkenyl and the two aryl groups each occupy adjoining edges of the Cu₄ core. The dimethylamino groups of the alkenyl ligand coordinate to copper, whereas those of the bridging aryl ligand are free. As a result the copper core is made up of copper atoms which are alternatingly two- and three-coordinate.The structure is discussed in terms of structural information now available for organocopper compounds. The geometry of the Cu₂C (bridge) moiety in organocopper cluster compounds as expected varies little with the nature of the bridging one-electron organo ligand (alkyl, alkenyl, alkynyl or aryl).     

Group ib organometallic chemistry : XXXIV. Thermal behaviour and chemical reactivity of tetranuclear Me2N-substituted diarypropenylcopper-copper anion (Vi2Cu4X2) and mixed diarylpropenyl/organocopper (Vi2Cu4R2) compounds

Thermal decomposition of configurationally pure 1,2-diarylpropenylcopper compounds Z-Vi₂CU₄Br₂ and Z-Vi₂Cu₄R₂ [Vi  (2-Me₂NC₆H₄)CC(Me)-(C₆H₄Me-4), R  2-Me₂NC₆H₄ or 4-MeC₆H₄CC] predominantly results in the formation of ViH. In contrast, only dimers (ViVi) were formed on thermolysis of (Z-ViCu₂OTf)_η which is a further illustration of the influence of the counter anion on the reactivity of organocopper cluster compounds. However, in both cases partial inversion of configuration, giving mixtures of isomers, was observed. The thermolysis of (Z-ViCu₂OTf)_η is discussed in terms of OTf-enhanced intraaggregate electron-transfer processes. The formation of incipient vinyl cations which are η²-coordinated to the copper cluster can explain the observed isomerization.Also in the hydrolysis reaction of Z-Vi₂Cu₄Br₂ mixtures of isomeric ViH compounds were obtained, the E/Z ratio being dependent on the type of reagent used. Mixtures of isomeric ViX compounds (X  Br, Cl, I) were formed in the reaction of Z-Vi₂Cu₄Br₂ with I₂ and CuCl₂. An explanation for the occurrence of isomerization is presented.Dimers (ViVi) were almost absent in the product mixture resulting from the reaction of Z-Vi₂Cu₄Br₂ with CuCl₂. In contrast, ViVi is obtained in about 50% yield from the reaction of ViLi with CuCl₂ which is in accord with earlier observations for the reaction of aryllithium compounds with cupric halides.Highly selective E-ViBr formation was observed in the reaction of E-ViLi with AgBr. This reaction probably proceeds via a thermally unstable Z-ViAg₂Br intermediate.     

Bis(dimethylmetall(III)glyoximato)metallate(II) (metall(III) = Al,Ga, In,metall(II) = Ni,Pd, Pt,Cu)

When the trimethyl derivatives of aluminium, gallium and indium react with glyoximato metallates, (R₂C₂N₂(O)OH)₂Met^II (R = H, CH₃; Met^II = Ni, Pd, Pt, Cu), in a $\text{2}\text{1}$ molar ratio, 2 mol of methane are evolved and monomeric bis(dimethylmetal(III)glyoximato)metallates(II) (metal(III) = Al, Ga, In) are formed in high yields. The vibrational and NMR spectra of the new complexes were measured and were partly resolved. The X-ray structure determinations of two of these compounds show non-planar structures of approximate C_2h and C₂ symmetry, respectively, with weak metal(III)?metal(II) π-interactions.     

Etude structurale de derives du fer carbonyle: II. Structure cristalline et moleculaire d'un complexe du fer carbonyle avec la 2-mercapto-pyridine,C5H4N(CO)6Fe2-μ4-S-Fe2(CO)6SC5H4N

The crystal and molecular structure of a complex prepared by reaction between Fe₃(CO)₁₂ and 2-mercaptopyridine and of formula C₅H₄N(CO)₆Fe₂-μ₄-S-Fe₂(CO)₆SC₅H₄N has been determined by a single-crystal X-ray study. The compound crystallises in the monoclinic space group $\text{P}\text{2}{}_1\text{n}$, with Z = 4. Data were collected on a NONIUS CAD-4 automatic diffractometer. The structure was solved both by the heavy-atom method and direct methods and refined to R and R″ values of 0.041 and 0.038 for 2089 independent reflections. The molecule contains four Fe(CO)₃ groups with two ironiron bonds bridged in a different way, and a sulphur atom tetrahedrally coordinated to the four iron atoms.     

Preferential energy transfer from N2(A) to specific energy levels of Cu atoms

Emission spectra resulting from reaction of “clean” N₂(A³ Σ_u⁺) with copper atoms were studied using a flowing afterglow apparatus. The population distribution of the Cu states was calculated from the spectrum; it indicates that Cu atoms are excited by nearly resonant energy transfer processes. N₂(A,v') + Cu(²S_{$\text{1}\text{2}$}) → N₂(X, v) + Cu^* , and that the transfer is most efficient for N₂(A,v') → N₂(X,v) transitions with large Franck-Condon factors. The preferential energy transfer results in population inversion between some of the Cu states.     

The behaviour of copper and thallium hexafluoromolybdates(V) in acetonitrile

Copper(I), copper(II), and thallium(III) hexafluoromolybdates(V), prepared by the oxidation of the metals in acetonitrile with molybdenum hexafluoride (A. Prescott, D.W.A.Sharp, and J.M. Winfield, $\text{J. Chem. Soc., Dalton Trans.}$, 1975, 963) have been investigated by cyclic voltametry. Half wave potentials, E_{$\text{1}\text{2}$} V vs. Ag^p+/Ag were obtained using a evacuable cell equipped with anexternal Ag^p+/Ag electrode, enabling strict anerobic conditions to be maintained. A number of reversible or quasi-reversible electron transfer processes have been observed, enabling comparison with synthetic work to be made. Results for Cu^I and Cu^II hexafluoromolybdates(V) are in accord with preparative experience. MoF₆. Mo^VI/Mo^VE_{$\text{1}\text{2}$} +1.600V, oxidises Cu metal to Cu^II in MeCN, and Cu^II is reduced by Cu^O to Cu^I , Cu^lI/Cu^IE_{$\text{1}\text{2}$} = +0.750 or +0.710V for Cu^I and Cu^II solutes respectively, Cu^I/Cu^OE$\text{1}\text{2}$ = ?0.720V not reversible. A wave at E_{$\text{1}\text{2}$} = ?0.350V is assigned to Mo^V/Mo^IV by analogy with Ag^I hexafluoromolybdate (D.W.A. Sharp, unpublished work). E_{$\text{1}\text{2}$} data for I₂ in MeCN, I₂/I₃^- = 0.280, I₃^?/I^? = -0.116V, suggest that reduction of MoF₆^? by I is not likely, in contrast to the situation in SO₂ (A.J. Edwards and R.D. Peacock, $\text{Chem. Ind.}$, 1960, 1441). Reduction of MoF₆^? by Cu^o in MeCN should be feasible, but appears to be very slow. Pure Tλ^III hexafluoromolybdate(V) is obtained from Tλ^o and MoF₆ only when the mole ratio MoF₆:Tλ>5:1. Smaller ratios produce yellow solids in which Mo:Tλ is $\text{ca}$. 2:1. Tλ^III is a stronger oxidising agent than Cu^II in MeCN, as oxidation of Cu^I by Tλ^III is rapid and quantitative. However a reversible electron transfer wave assignable to Tλ^III/Tλ^I is not observed in the expected fange +1.600 to +0.710V possibly because of solute-electrode interactions.     

The mechanism of ascorbic acid oxidation by Cu(II)-poly-4-vinylpyridine complexes

The mechanism of ascorbic acid (DH₂) oxidation with molecular oxygen catalysed by the polynuclear complex of Cu²⁺ with poly-4-vinylpyridine (PVP), partially quaternized by dimethylsulphate, has been studied. The half-conversion time of the reaction of DH₂ with Cu(II) PVP under anaerobic conditions is independent of [Cu²⁺]. At pH 3.5, t_0.5 (sec) = 0.8 + 5 × 10^?4 [DH₂]. The formation of an intermediate cupric-ascorbate complex is suggested (K_c ≈ 10⁴ M^?1). Free radicals of ascorbic acid are detected by the ESR-method combined with a flow technique. The small steady-state concentration of radicals indicates that their decay occurs inside the macromolecular complex. The rate constant of the PVP Cu(II) DH^? ternary complex dissociation is ≈0.4 sec^?1 (pH 3.5). The reaction of Cu(I) PVP with O₂ is not accompanied by formation of O₂^? outside the macromolecule bulk. The rate constant of this reaction is 1.3 ± 0.15) × 10² M^?1 sec^?1 (pH 3.5). The cyclic mechanism of the catalytic reaction is suggested to include interchange of the redox state of copper-ions. About $\text{2}\text{3}$ of the total copper ion exists in the form Cu(I) PVP during the reaction at pH 3.5. The rate of DH₂ oxidation under these conditions is limited by the rate of Cu(I) PVP reaction with O₂. At pH 4.5 the overall reaction rate is limited by the rate of interaction of Cu(II) PVP with DH^?.     

Substitution in barium-fluoride apatite: The crystal structures of Ba10(PO4)6F2, Ba6La2Na2(PO4)6F2 and Ba4Nd3Na3(PO4)6F2

The crystal structures of the apatites Ba₁₀(PO₄)₆F₂(I), Ba₆La₂Na₂(PO₄)₆F₂(II) and Ba₄Nd₃Na₃(PO₄)₆F₂ (III) have been determined by single-crystal X-ray diffraction. All three compounds crystallize in a hexagonal apatite-like structure. The unit cells and space groups are: I, a = 10.153(2), c = 7.733(1)Å, $\text{P6}{}_3\text{m}\text{; a = 9.9392(4), c = 7.4419(5)}$Å, $\text{P}\text{6}$; III, a = 9.786(2), c = 7.281(1)Å, $\text{P}\text{3}$. The structures were refined by normal full-matrix crystallographic least squares techniques. The final values of the refinement indicators R_w and R are: I, R_w = 0.026, R = 0.027, 613 observed reflections; II, R_w = 0.081, R = 0.074, 579 observed reflections; III, R_w = 0.062, R = 0.044, 1262 observed reflections.In I, the Ba(1) atoms located in columns on threefold axes, are coordinated to nine oxygen atoms; the Ba(2) sites form triangles about the F site and are coordinated to six oxygen atoms and one fluoride ion. The fluoride ions are statistically displaced ～0.25 Å from the Ba(2) triangles. This displacement of the F ions is analogous to the displacement of OH ion in Ca₁₀(PO₄)₆(OH)₂.The structures of II and III contain disordered cations. In II there is disorder between La and Na in the column cation sites as well as triangle sites. In III, Nd and Na ions are ordered in the column sites, but there is disorder among Ba and the remaining Nd and Na ions in the triangle sites to give an average site population of $\text{2}\text{3}\text{Ba}\text{,}\text{1}\text{6}\text{Nd}\text{,}\text{1}\text{6}\text{Na}$. The coordination of the rare earth ions and Na ions in the ordered column sites are nine and six oxygens, respectively, in accord with the greater charge of the rare earth ions as compared with Na. The F ions in both II and III suffer from considerable disorder in position, and their locations are not precisely known.     

Münzmetallcluster mit verbrückenden Imido‐ und Amidoliganden: [{Li(dme)3}4][Cu18(NPh)11] und [Ag6(NHPh)4(PnPr3)6Cl2]

Copper and Silver Clusters with Bridging Imido and Amido Ligands From the reactions of copper and silver chloride with tertiary phosphines and lithiated aniline the compounds [{Li(dme)₃}₄][Cu₁₈(NPh)₁₁] ( 1 ) and [Ag₆(NHPh)₄(PⁿPr₃)₆Cl₂] ( 2 ) were obtained. The structure of the anion in 1 is closely related to the structures of the reported clusters [Cu₁₂(NPh)₈]^4– [1] and [Cu₂₄(NPh)₁₄]^4– [2]: 1 represents the third phenyl imido bridged copper cluster which contains parallel Cu₃‐ and Cu₆‐planes. The dimeric compound 2 consists of two Ag₃ units with bridging phenyl amido ligands. Two chloride and six phosphine ligands complete the ligand sphere and shield the metal core effectively.     

The crystal structure of Cu4(PO4)2O

Cu₄(PO₄)₂O crystallizes in the space group $\text{P}\text{1}$ with a = 7.5393(8) Å, b = 8.1021(9) Å, c = 6.2764(8) Å, α = 113.65(1)°, β = 98.42(1)° and γ = 74.19(1)°. The structure was refined by full-matrix least-squares techniques using automatic diffractometer data to R = 0.046 (R_w = 0.056). Four unique copper atoms are in six, five-, and four-coordinated polyhedra which are linked together to form a three-dimensional network. The structure is best described in terms of a cubic close-packed array of oxygen atoms with one-tenth of the possible anion sites vacant.     

Synthesis and properties of some 2-(dimethylamino)methyl-substituted arylcopper compounds

The synthesis and isolation of 2-[(dimethylamino)methyl]phenylcopper and its 5-methyl, 5-methoxy, 5-chloro and 3-chloro derivatives are described. These hydrocarbon-soluble arylcopper compounds are appreciably more thermally stable than phenylcopper (e.g. 2-[(dimethylamino)methyl]phenylcopper decomposes only at 175–185°). They also show improved hydrolytic and oxidative stability.Lithiation of 1-methoxy-4-[(dimethylamino)methyl]naphthalene with butyllithium occurs at the 5-position. Metathesis of 1-methoxy-4-[(dimethylamino)methyl]-5-lithionaphthalene with cuprous bromide affords the corresponding organocopper compound.