Group IB organometallic chemistry : XXXII. Arylcopper compounds ArnCun as intermediates in organometallic synthesis. Single-step synthesis and dynamic NMR spectroscopy of diorganotin dihalides Ar2-nRnSnX2 (Ar  2-Me2NCH2C6H4 or (S)-2-Me2NCHMeC6H4; n  0 or 1)

The selective, single-step synthesis of (2-Me₂NCHZC₆H₄)RSnX₂, in which Z  H or Me, R  Me or Ph and X  Cl or Br, starting from the tetranuclear copper cluster compound (2-Me₂NCHZC₆H₄)₄Cu₄ and RSnX₃ is described. Reaction of (2-Me₂NCH₂C₆H₄)₄Cu₄ with SnBr₄ in a 1/2 molar ratio afforded (2-Me₂NCH₂C₆H₄)₂SnBr₂ in almost quantitative yield.¹H NMR spectroscopic data of these novel compounds, which are monomeric in solution, indicate that: (i) intramolecular SnN coordination renders the Sn atom in (2-Me₂NCHZC₆H₄)RSnX₂ pentacoordinate, with the organo ligands residing in the equatorial plane of a trigonal bipyramidal structure, and the Sn atom in (2-Me₂NCH₂C₆H₄)₂SnBr₂ hexacoordinate, with trans organo groups and a cis arrangement for the Br and the N atoms; (ii) in pyridine the Sn atom in (2-Me₂NCHZC₆H₄)RSnX₂ becomes hexacoordinate by complex formation with the solvent but that intramolecular SnN coordination has been retained.The stereochemical lability of the pentacoordinate Sn center in the diorganotin dihalides (2-Me₂NCHZC₆H₄)RSnX₂, which contain a dissymmetrical equatorial plane, has been established on the basis of the dynamic NMR spectra of     

Aspects of transmetallation reactions of 2-Me2NCH2C6H4- and 2,6-(Me2NCH2)C6H3-Metal (Pd,Pt, Hg,Tl) complexes with metal carboxylates and low-valent metal (Pd,Pt) complexes

A study has been made of reactions involving organometallic compounds containing ortho-Me₂NCH₂ substituted aryl ligands. The single step syntheses of the new compounds [(2-Me₂NCH₂C₆H₄)₂TlCl], [ [{(S)-2-Me₂NCH(Me)C₆H₄}₂TlCl], [{(S)-2-Me₂NCH(Me)C₆H₄}TlCl₂], [{2,6-(Me₂NCH₂)₂C₆H₃}TlClBr] and [{2,6-(Me₂NCH₂)₂C₆H₃}HgCl] are described. Stable internal NTl coordination at low temperatures has been established for the C-chiral thallium compounds. Reactions of the other Tl and Hg compounds and of [(2-Me₂NCH₂C₆H₄)₂Hg] with Pd(O₂CMe)₂, and also of the reverse reaction of cis-[(2-Me₂NCH₂C₆H₄)₂Pd] with Hg(O₂CR)₂ or Tl(O₂CR)₃, gave transmetallation of one organo ligand and led to a single mono-organopalladium compound and corresponding by-products. Reaction of cis-[(₂-Me₂NCH₂C₆H₄)₂Pd] with Pd(O₂CR)₂ gave the dimeric compound [{(2-Me₂NCH₂C₆H₄)Pd(O₂CR)}₂]. cis-[(2-Me₂NCH₂C₆H₄)₂Pt] did not react with Pd(O₂CMe)₂, while reaction of trans-[(2-Me₂NCH₂C₆H₄)₂Pt] or cis-[(2-Me₂NC₆H₄CH₂)₂Pt] with Pd(O₂CMe)₂ resulted in decomposition. Upon heating, trans-[(2-Me₂NCH₂C₆H₄)₂Pt] was isomerized to cis-isomer. A redox reaction between [(2-Me₂NCH₂C₆H₄)₂Hg] and [Pt(COD)₂] (COD  1,5-cyclo-octadiene) and [Pd₂(DBA)₃] (DBA  dibenzylideneacetone) gave the cis-isomers of [(2-Me₂NCH₂C₆H₄)₂M] (M  Pd, Pt).The results are discussed in terms of influence of internal coordination of the CH₂NMe₂ group. It is concluded that although internal coordination of the CH₂NMe₂ ligand can stabilize metal—carbon bonds it cannot prevent cleavage of such bonds by electrophiles. In this respect, there is no difference in the behaviour of Hg(O₂CR)₂ and Tl(O₂CR)₃. The reactions are influenced by the metal—nitrogen bond strength, which follows the order PtN > PdN > HgN, TlN. The reactivity of Pt compounds is greatly influenced by their structure and type of ligand. It is proposed that cleavege of PdC bonds occurs mainly by a mechanism involving direct electrophilic attack at the carbon centre.     

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.     

Characteristic structural features of cyclopentadienyl derivatives of post-transition metals : II. Synthesis and structure of tris(triphenylphosphinegold)tetraphenylcyclopentadiene tetrafluoroborate

The trinuclear cationic complex [Ph₄C₅(AuPPh₃)₃⁺[BF₄]^- (I) obtained by interaction of C₅HPh₄AuPPh₃ or Ph₄C₅(AuPPh₃)₂ with [AuPPh₃⁺[BF₄]^- in THF was studied by X-ray diffraction. In the presence of benzene, triclinic crystals of the solvate [Ph₄C₅(AuPPh₃)₃]⁺[BF₄]^-· 2 C₆H₆ are formed, a = 12.845(6), b = 16.042(8), c = 22.642(11) Å, α = 86.62(4), β = 77.51(4), γ = 76.05(4)°, space group P$\text{1}$, Z = 2, 9494 reflections with I > 2σ (λ(Mo-K_α), θ/2θ scan, 2θ < 46°), with absorption correction R = 0.054. The complex represents a diaurated cation of tetraphenylcyclopentadienyl(triphenylphosphine)gold, containing a triangular Au₂C fragment (AuAu 2.820(1) Å) which is bonded to the third Au atom (AuAu 3.021(1) Å), coordinated to the cyclopentadienyl ligand by a bond intermediate between η¹(σ) and η³ (AuC 2.21(2), 2.60(2) and 2.71(2) Å).     

Arylmercury(II) compounds involving intramolecular coordination via 2-Me2NCH2- and chiral (S)-2-Me2NCHMe-ring substituents

Arylmercury compounds of the type Ar₂Hg and ArHgX (X = Cl, OAc) have been synthesized and characterized by ¹H and ¹³C NMR spectroscopy; the Ar group was either 2-Me₂NCH₂C₆H₄ or (S)-2-Me₂NCH(Me)C₆H₄, both of which contain N-donor ligands. The observation of anisochronous NMe resonances in (S)-2-Me₂NCH(Me)C₆H₄HgX (X = Cl, OAc) at low temperature indicates that in solution the mercury centre is three-coordinate as a result of stable intramolecular HgN coordination     

Triaryl-silyl, -germyl,and -stannyl radicals .MAr3 (M = Si,Ge, or Sn and Ar = 2,4,6-Me3C6H2) and .Ge(2,6-Me2C6H3)3: Synthesis and ESR studies

The triarylmetal-centred radicals ^.MAr₃ (M = Si, Ge, or Sn; Ar = 2,6-Me₂C₆H₃ or 2,4,6-Me₃C₆H₂) have been prepared from the appropriate triarylmetal chloride, MAr₃Cl, and an electron-rich olefin [R$\text{NCH}{}_2\text{CH}{}_2\text{NRC}$]₂ (R = Me or Et) under UV irradiation in toluene at low temperature. The triarylgermyl radicals are persistent (t$\text{1}\text{2}$ > 24 h, 20°C) whilst the analogous tin and silicon radicals are only stable under constant irradiation at temperatures below ?20°C; the ESR spectra of the germanium radicals and of ^.Si(2,4,6-Me³C₆H₂)₃ (which is the first triarylsilyl radical to be spectroscopically identified) show coincidental equivalence of all the proton couplings due to twisting of thearomatic rings into a “propeller” arrangement about the metal. The synthesis and characterisation of precursors to these radicals are also reported.     

Darstellung,Eigenschaften und Reaktionsverhalten von 2-(Dimethylaminomethyl)phenyl- und 8-(Dimethylamino)naphthylsubstituierten Lithiumhydridosilylamiden – Bildung von Silaniminen durch Lithiumhydrideliminierung

Preparation, Properties, and Reaction Behaviour of 2-(Dimethylaminomethyl)phenyl- and 8-(Dimethylamino)naphthylsubstituted Lithium Hydridosilylamides – Formation of Silanimines by Elimination of Lithium Hydride The hydridosilylamines Ar(R)Si(H)–NHR′ ( 2 a : Ar = 2-Me₂NCH₂C₆H₄, R = Me, R′ = CMe₃; 2 b : Ar = 2-Me₂NCH₂C₆H₄, R = Ph, R′ = CMe₃; 2 c : Ar = 2-Me₂NCH₂C₆H₄, R = Me, R′ = SiMe₃; 2 d : Ar = 8-Me₂NC₁₀H₆, R = Me, R′ = CMe₃; 2 e : Ar = 8-Me₂NC₁₀H₆, R = Ph, R′ = CMe₃; 2 f : Ar = 8-Me₂NC₁₀H₆, R = Me, R′ = SiMe₃) have been synthesized from the appropriate chlorosilanes Ar(R)SiHCl either by reaction with the stoichiometric amount of Me₃CNHLi ( 2 a , 2 b , 2 d , 2 e ) or by coammonolysis in liquid NH₃ with chlorotrimethylsilane in molar ratio 1 : 3 ( 2 c , 2 f ). Treatment of 2 a–2 f with n-butyllithium in equimolar ratio in n-hexane resulted in the lithiumhydridosilylamides Ar(R)Si(H)–N(Li)R′ 3 a–3 f . The frequencies of the Si–H stretching vibration and ²⁹Si–¹H coupling constants in the amides are smaller than in the analogous amines indicating a higher hydride character for the hydrogen atom of the Si–H group in the amides compared to the amines. Results of NMR spectroscopic studies point to the existence of a (Me₂)N → Si coordination bond in the 8-(dimethylamino)naphthyl-substituted amines and amides. The amides 3 a–3 c are stable under refluxing in m-xylene. At the same conditions 3 d and 3 e eliminate LiH and the silanimines 8-Me₂NC₁₀H₆(R)Si=NCMe₃ ( 4 d : R = Me, 4 e : R = Ph) are formed. The amides 3 a–3 d und 3 f react with chlorotrimethylsilane in THF to give the corresponding N-substitution products Ar(R)Si(H)–N(SiMe₃)R′ 6 a–6 d and 6 f in good yields. 4 d is formed as a byproduct in the reaction of 3 d with chlorotrimethylsilane. In n-hexane and m-xylene these amides are little reactive opposite to chlorotrimethylsilane. 6 a–6 d and 6 f are obtained in very small amounts. In the case of 3 d besides the N-substitution product 6 d the silanimine 4 d is obtained. In contrast to chlorotrimethylsilane the amides 3 a and 3 f react well with chlorodimethylsilane in m-xylene producing 2-Me₂NCH₂C₆H₄(H) SiMe–N(SiHMe₂)CMe₃ ( 7 a ) and 8-Me₂NC₁₀H₆(H)SiMe–N(SiHMe₂)SiMe₃ ( 7 f ).     

Theoretical investigation of structures,electronic spectra and nonlinear optical properties of gold-pentacene (Au2C22H14) complexes

Eight systems formed by adding two gold atoms to a pentacene (Au₂C₂₂H₁₄) were investigated by density functional theory. The structures, electronic spectra and second-order nonlinear optical properties of these eight systems were calculated and were compared with AuC₂₂H₁₄. The covalent bonds were observed in these eight systems (Au₂C₂₂H₁₄) studied, and the Au–C bond can be strengthened by increasing the number of Au atoms. Moreover, introduction of the second Au atoms further increases the possible transitions and obvious red shift, except for system 4. This indicates that the properties of electronic transition can be tuned through changing the number of Au atoms. Systems 1, 1′, 2 and 2′ possess moderate molecular second-order polarizabilities, and β_vec of System 1 is about six times larger than that of (AuC₂₂H₁₄). Thus, the position of Au atoms has also great influence on the second-order NLO response.     

The crystal structure of tris(triphenylphosphine)gold(I)-[dodecahydrido-6-thia-nido-decaborate(1—)]

The crystal structure of tris(triphenylphosphine)gold(I)[dodecahydrido-6-thia-nido-decaborate(1—)], [(C₆H₅)₃P]₃AuB₉H₁₂S, has been determined using X-ray techniques and counter data. The compound is a salt consisting of [(C₆H₅)₃P]₃Au⁺ cations and B₉H₁₂S^? anions. The cation is trigonal and nearly planar with AuP distances of 2.382(5) Å and PAuP anglés of 119.3(36)°. The B₉H₁₂S^? thiaborane anion is an open icosahedral fragment with the S atom in the 6 position, on the periphery of the decaborane polyhedron. The structure is the same as that found in solution for the isoelectronic B₁₀H₁₄^2? anion. Crystals are triclinic, space group P$\text{1}$, with a = 13.086(12), b = 19.635(32), c = 11.180(8) Å, α = 103.60(16), β = 72.10(9), and γ = 94.76(15)°. The structure was refined by least squares to a conventional R of 0.077.     

Intramolecular dynamics of 3c2e bonded aryl groups in polynuclear aryl-copper, -silver and -gold derivatives

Dynamic ¹H and ¹³C NMR studies reveal that the prochiral methylene group in 2-(Me₂NCH₂)C₆H₄-metal compounds R₄M₂Li₂ (M = Cu, Ag or Au) is an excellent probe for the monitoring of the configuration at C(1) in each of the 2-(Me₂NCH₂)C₆H₄MLi units. In this way the rotation of 3c2e bonded aryl groups around the C(1)?C(4) axis has been unambiguously establish for the first time. Chiral labelling of the 3c2e bonded group provides information concerning the stereochemistry of the R₄M₂Li₂ cluster.     

Structural chemistry of bimetallic hydride complexes of titanium and aluminium: I. Crystal and molecular structure of [(η5-C5H5)2,Ti(μ-H)2AlH2]2(CH3)2NCH2CH2N(CH3)2C6H6

The structure of a titanium aluminium hydride complex of composition [(C₅H₅)₂TiAlH₄]₂(CH₃)₂NC₂H₄N(CH₃)₂C₆H₆ has been determined by X-ray diffraction. The complex forms triclinic crystals with unit cell dimensions a = 8.406(2), b = 10.117(2), c = 11.269(3) Å; α = 112.01(2)°, β = 109.25(2)°, γ = 87.04(2)°, space group P$\text{1}$, Z = 2 and density d = 1.21 g/cm³. The structure was refined to give a discrepancy index R = 0.056. The crystals are composed of centrosymmetric molecules of (Cp₂TiAlH₄)₂TMEDA (Cp = η⁵-cyclopentadienyl) and molecules of crystal benzene. Two moieties of Cp₂TiH₂AlH₂ are linked by a tetramethylethylenediamine molecule (r_AlN 2.11 Å). The aluminium atom is bonded to a titanium atom by a double hydride bridge (r_AlH b = 1.8, 1.6 Å, r_TiH b = 1.6 Å), and has trigonal bipyramidal stereochemistry, [H₄N] (r_AlH t = 1.6 Å).     

1,1′-Disubstituierte Titanocen-dithiolen-Chelate des Typs (η5-Me3EC5H4)2Ti(S2C2R2) (E = C,Si, Ge)

1,1′-Disubstituted Titanocene Dithiolene Chelates of Type (η⁵-Me₃EC₅H₄)₂Ti(S₂C₂R₂) (E = C, Si, Ge) Reaction of the titanocene dichlorides (η⁵-Me₃EC₅H₄)₂TiCl₂ (E = C, 1a ; E = Si, 1b ; E = Ge, 1c ) with the 1,2-dithiolates (NaS)₂C₂H₂, (NaS)₂C₂(CN)₂ or (LiS)₂C₆H₃Me-4 gave the new titanocene dithiolene chelates (η⁵-Me₃EC₅H₄)₂Ti(S₂C₂H₂) ( 2a–c ), (η⁵-Me₃EC₅H₄)₂Ti[S₂C₂(CN)₂] ( 3a–c ) and (η⁵-Me₃EC₅H₄)₂Ti(S₂C₆H₃Me-4) ( 4a–c ). These have been characterized by ¹H NMR, IR, and mass spectroscopy, and have been compared with the unsubstituted η⁵-C₅H₅ analogues 2d, 3d and 4d . Activation energies for the chelate ring inversion in solution of 2a–c, 3a–d and 4a–c have been estimated by temperature-dependent ¹H NMR spectroscopy.     

Synthese und Struktur von K[Au(AuCl)(AuPPh3)8)](PF6)2

Synthesis and Structure of K[Au(AuCl)(AuPPh₃)₈)](PF₆)₂ Photolysis of a mixture of Ph₃PAuCl and Ph₃PAuN₃ (1 : 3) in toluene/THF yields in the presence of Na₂[(C₅H₅)V(CO)₃] the new cluster cation [Au(AuCl)(AuPPh₃)₈]⁺. It crystallizes from CH₂Cl₂ after addition of KPF₆ as K[Au(AuCl)(AuPPh₃)₈](PF₆)₂ · 4 CH₂Cl₂. The compound forms a tetragonal structure with the space group P4/n and a = 2552.6(3), c = 1401.1(1) pm, Z = 2. The cluster cations with a spheroidal topology are built up of a centered Au₈ crown whose central gold atom in addition binds a AuCl group. The cluster occupies with its center and AuCl group a fourfold axis of the space group. The radial bonds between the central and the peripheral Au atoms are in the range of 263.7 to 268.4 pm, while the distances between the peripheral atoms are longer with 291.7 to 350.9 pm.     

Syntheses of some mixed AuOs and PtOs clusters and the X-ray structure of [Os4H2(CO)12(AuPPh3)2]

Some reactions of [Os₄H₃(CO)₁₂AuPR₃] (R = Et, Ph) resulting in the formation of [Os₄H₂(CO)₁₂(AuPR₃)₂] are presented. A single-crystal X-ray structure of [Os₄H₂(CO)₁₂(AuPPh₃)₂] is reported and reveals a novel Ph₃PAuAuPPh₃ unit asymmetrically bridging one edge of an Os₄ tetrahedron, the first example of a mixed gold-metal carbonyl cluster with an AuAu bond.     

Preparation of ortho-substituted aryldifluorophosphines, 2-XC6H4PF2 (X = MeO or Me2N), and some of their derivatives. X-ray crystal structure determination of (2-MeOC6H4P)4 and of the platinum complex,Cl2Pt(2-MeOC6H4PF2)2

The preparation of the ortho-substituted aryldifluorophosphines 2-MeOC₆H₄PF₂ and 2-Me₂NC₆H₄PF₂ by chlorine-fluorine exchange from the corresponding dichlorophosphines using sodium fluoride in acetonitrile in the presence of a crown ether is described. The ortho-substituted aryldichlorophosphines 2-MeOC₆H₄PCl₂ and 2-Me₂NC₆H₄PCl₂ were prepared from the respective bis(N,N-dimethylamino) phosphines by cleavage of the PN bonds with hydrogen chloride. The reaction of 4-fluoroanisole and 2-methoxy-phenyllithium with phosphorus trichloride did not yield the expected chlorophosphines, i.e. 2-MeO-5-F-C₆H₃PCl₂ and 2-MeOC₆H₄PCl₂, but led to formation of 4-fluorophenyldichlorophosphite in the former, and to tris(2-methoxyphenyl)phosphine in the latter case. The difluorophosphine 2-MeOC₆H₄PF₂ was found to undergo a spontaneous oxidation-reduction reaction with formation of the tetrafluorophosphorane 2-MeOC₆H₄PF₄, and the cyclotetraphosphine (2-MeOC₆H₄P)₄. A single-crystal X-ray structure determination of the latter indicated the presence of a strongly puckered four-membered ring with PP bond lengths ranging between 222 and 223 pm, and endocyclic bond angles of 84°. Vicinal MeOC₆H₄ groups were found arranged trans to each other. Dichloroplatinum(II) complexes were prepared, involving the two new fluorophosphines, 2-XC₆H₄PF₂ (X = MeO or Me₂N), as ligands. In neither case was any evidence found for coordination between platinum and oxygen or nitrogen, and the fluorophosphines were found to function solely as phosphorus donors. The absence of interaction between platinum and the oxygen atom in the ortho position of the ligand 2-MeOC₆H₄PF₂ was confirmed in a single-crystal X-ray determination of the complex Cl₂(2-MeOC₆H₄PF₂)₂Pt. The compound was found to exist as a planar, cis-coordinated species with PtCl bond lengths between 232 and 234 pm, and a PtP bond length of 218 pm. All compounds were characterized by NMR spectroscopy (¹H, ³¹P and ¹⁹F, where applicable).     

An experimental and theoretical investigation on hypervalent organoselenium(II) halides: Case study of [2-(Et2NCH2)C6H4]SeX (X = Cl,Br, I)

Cleavage of the Se–Se bond in [2-(Et₂NCH₂)C₆H₄]₂Se₂ (1) with SO₂Cl₂ (1:1 molar ratio) yielded the organoselenium(II) chloride [2-(Et₂NCH₂)C₆H₄]SeCl (2). Treatment of 2 with excess of KX yielded the organoselenium(II) halides [2-(Et₂NCH₂)C₆H₄]SeX [X = Br (3), I (4)]. The new compounds 2–4 were characterized by solution NMR spectroscopy (¹H, ¹³C, ⁷⁷Se, 2D experiments). The solid-state molecular structures of 2, 2·HCl and 3 were established by single crystal X-ray diffraction. Distorted T-shaped coordination geometries of type (C,N)SeX (X = Cl, Br) and CSeCl₂ were found for the neutral halides 2 and 3, and the zwitterionic species [2-{Et₂N⁺(H)CH₂}C₆H₄]SeCl₂￣ (2·HCl), respectively. DFT calculations were performed on 2–4 and the related tellurium compounds [2-(Et₂NCH₂)C₆H₄]TeX [X = Cl (5), Br (6) and I (7)] in order to elucidate the bond nature and FT-Raman features of this class of organochalcogen(II) derivatives.     

Group IB organometallic chemistry : XXXVII. Complex forming reactions of polynuclear arylcopper compounds: CalkP bond cleavage in 1,2-bis(diphenylphosphino)ethane (diphos) by (2-Me2NCH2C6H4)4Cu4 and crystal structure of [(C6H5)2PCu · diphos]2 · 2 C6H6

Molecular weight measurements and microwave titrations indicate that no interaction occurs between tetrameric 2-Me₂NCH₂C₆H₄Cu (Ar₄Cu₄) and the monodentate ligands PPh₃, CH₃CN or pyridine. However, the tetrameric structure Ar₄Cu₄ breaks down upon interaction (1/1 molar ratio ArCu/L) with the bidentate ligands (L) Diphos or cis-DPPEE to give the monomeric 1/1 complexes ArCu · L.Addition of Diphos to ArCu · Diphos or conducting the reaction of Ar₄Cu₄ with Diphos in a 1/2 ratio (ArCu/Diphos) gives rise to a C_alkP bond cleavage reaction resulting in the formation of dimeric (Ph₂PCu · Diphos)₂ · 2 C₆H₆, ArH and Ph₂PCHCH₂.The molecular structure of (Ph₂PCu · Diphos)₂ · 2 C₆H₆, has been determined by a single-crystal X-ray diffraction study. Crystals are monoclinic, space group P2₁/c and have Z  2 in a unit cell of dimensions a  12.997(6), b  12.669(7), c  22.839(9) Å and β  94.48(4)°. The structure was refined to R  0.048 for 3048 independent reflections. The four copper atoms in the dimer are held together by two Ph₂P bridges. The bonding in the dimer is discussed.     

Complexes of N-Phosphorylated Thioureas RNHC(S)NHP(O)(OiPr)2 (R = 2-MeC6H4, 2,6-Me2C6H3, 2,4,6-Me3C6H2) With Nickel(II)

The reaction of O,O′-diisopropylphosphoric acid isothiocyanate (iPrO)₂P(O)NCS with 2-methylaniline 2-MeC₆H₄NH₂, 2,6-dimethylaniline 2,6-Me₂C₆H₃NH₂, or 2,4,6-trimethylaniline 2,4,6-Me₃C₆H₂NH₂ leads to the N-phosphorylated thioureas RNHC(S)NHP(O)(OiPr)₂ (R = 2-MeC₆H₄?, HL^I ; 2,6-Me₂C₆H₃?, HL^II ; 2,4,6-Me₃C₆H₂?, HL^III ). Reaction of the potassium salts of HL^{I –III} with Ni(II) in aqueous EtOH leads to [Ni(L^I–III-N,S)₂] ([NiL^I–III ₂ ]) chelate complexes. The compounds obtained were investigated by ¹H, ³¹P{¹H} NMR spectroscopy and microanalysis. The molecular structure of the thiourea HL^III was elucidated by single crystal X-ray diffraction analysis. Single crystal X-ray diffraction studies showed that HL^III forms both intra- and intermolecular hydrogen bonds, which in turn leads to the formation of polymeric chains. One of the intermolecular hydrogen bonds is of the type N?H…S. Moreover, the formation of intermolecular C?H…η⁶-phenyl interactions was established.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and structure of tris(4-<Emphasis Type="Italic">N,N</Emphasis>-dimethylaminophenyl) antimony(V) dicarboxylates and diaroxides

Tris(4-N,N-dimethylaminophenyl)antimony dicarboxylates (4-Me₂NC₆H₄)₃Sb[OC(O)R]₂ (R = C₆H₄Me-2 (I), C₆H₄Me-4 (II), CH=CHPh (III)), (4-Me₂NC₆H₄)₃Sb[OC(O)C(O)O] (IV), and (4-Me₂NC₆H₄)₃Sb[OC(O)C₆Cl₄C(O)O] (V)) and tris(4-N,N-dimethylaminophenyl)antimony diaroxides (4-Me₂NC₆H₄)₃Sb(OAr)₂ (Ar = Ph (VI), C₆H₂Br₃-2,4,6 (VII), and C₆H₃Me₂-2,6 (VIII)) have been synthesized by the reaction of tris(4-N,N-dimethylaminophenyl)antimony in ether with carboxylic acids or phenols in the presence of hydrogen peroxide. According to X-ray diffraction analysis data, the Sb atoms in compounds I and VII have a distorted trigonal-bipyramidal coordination, and the axial OSbO angles are 175.4(1)° and 177.9(3)°, respectively. The Sb-O bond lengths are 2.133(3) and 2.142(2) Å in compound I and 2.089(5) Å in compound VII.     

Steric control in the formation of amine or amide complexes from [Mo(No){HB(3,5-Me2C3N2H)3}I2]

The reaction between [Mo(NO){HB(3,5-Me₂C₃N₂H)₃}I₂] and pyrrolidine or piperidine produces both the amine complexes [Mo(NO){HB(3,5-Me₂C₃N₂H)₃} I(NHC_nH₂n)] (n = 4 or 5) and the amide complexes [Mo(NO){HB(3,5-Me₂C₃N₂H)_3} I(NC_nH_2n)]. The role of steric factors in the formation of these compounds is discussed.