Structural studies of carbene complexes: The crystal structure of the secondary carbene complex RuI2[CHN(CH3)(p-CH3C6H4)](CO)(CN-p-CH3C6H4)(P(C6H5)3)

Crystal and molecular structures of the title compound have been determined from a three-dimensional X-ray analysis using diffractometer data. The crystals are triclinic, space group P$\text{1}$, with Z = 2 in a unit cell of dimensions a = 11.640(1), b = 10.9139(8), c = 16.587(2) Å, α = 87.983(5), β = 99.670(6), λ = 62.250(5)°. Full matrix least squares refinement has given a final R-factor of 0.043 for 2726 reflections for which I > 2σ(I).The crystal structure consists of discrete molecules of neutral complex together with water molecules which are hydrogen bonded into pairs [O ? O separation 2.60 Å]. 0The (H₂0)₂ units do not hydrogen bond to any other atoms. The ruthenium coordination is octahedral with trans carbene and isocyanide, cis iodides, and cis phosphine and carbonyl ligands. The Ru-donor distances are 2.776(2) [I trans to -PPh₃], 2.782(1) [I trans to -CO], 2.342(4) [PPh₃], 1.855(15) [CO], 2.046(15) [C(carbene)], and 1.998(16) Å [C(isocyanide)]. The bond lengths are discussed in terms of the trans effects of the ligands. The C(carbene)-N distance is 1.26(2) Å and the Ru—C(carbene)—N angle is 141.5(5)°.     

Synthesis and Characterization of N3P3(O2C12H8)2(OC6H4Si(CH3)3)(OC6H4Br) and Its Conversion to Nanostructured Si Material

A new silicated cyclotriphosphazene N₃P₃(O₂C₁₂H₈)₂(OC₆H₄Si(CH₃)₃)(OC₆H₄Br) 1 has been synthesized and characterized. The solid state pyrolysis of 1 in air gives a nanostructured SiP₂O₇ 3D network. The morphology of the network strongly depends on the temperature of the pyrolysis. Spinal-like columns and ring-shaped SiP₂O₇ are formed at 800 °C, while, at 600 °C, fused grains of about 300 nm were observed. Based on air TG and DSC thermal studies, we propose the mechanism of formation for the nanostructured network.     

The molecular and crystal structure of an allylpalladium- (II) triazenido complex: [(1-3-η-C3H5)Pd(II)(p-CH3C6H4NNNC6H4CH3-p)]2

For the class of compounds mentioned in the title it is difficult to the stucture unambiguously on the molecular and crystal structure of CH₃-p)]₂ by single crystal X-ray analysis. The crystal data are: M == 743 a.m.u. Space group P2₁/c. a = 8.510(2), b = 40.652(9), c = 9.762(2) Å, β = 103.61(2)° D_c = 1.50 g/cm³. R = 0.041, R = 0.060, based on 3978 independent reflections. The two π-allylpalladium residues are bridged azenido groups, gaining an approximate square planar coordination around each heavy atom. The two allyl units are stereochemically equivalent, with the central carbon atoms pointing outwars. The rigid triazenido groups force the two palladium atoms into close contact (2.86 Å). The aromatic rings are somewhat rotated with respect to the bonded NNN planes, but some π-conjugation over the whole ligand is still retained.     

Synthesis and derivatization, structures and transition metal (Mo(0), Fe(II), Pd(II) and Pt(II)) complexes of phenylaminobis(diphosphonite), PhN{P(OC6H4OMe-o)2}2

The synthesis, derivatization and coordination behavior of a new aminobis(diphosphonite), PhN{P(OC₆H₄OMe-o)₂}₂ (1) is described. The ligand 1 reacts with H₂O₂, elemental sulfur or selenium to give the corresponding dichalcogenides PhN{P(E)(OC₆H₄OMe-o)₂}₂ (E = O, 2; S, 3; Se, 4) in good yield. Reactions of 1 with Mo(CO)₆, Pd(NCCH₃)₂Cl₂ and Pt(COD)Cl₂ resulted in the formation of the chelate complexes, Mo(CO)₄[PhN{P(OC₆H₄OMe-o)₂}₂] (5) and MCl₂[PhN{P(OC₆H₄OMe-o)₂}₂] (M = Pd,7; M = Pt, 8) whereas in the reaction of 1 with [CpFe(CO)₂]₂, one of the P-N bonds cleaves due to the metal assisted hydrolysis to give a mononuclear complex, [CpFe(CO){P(O)(OC₆H₄OMe-o)₂}{PhN(H)(P(OC₆H₄OMe-o)₂)}] (6). The molecular structures of 1, 4, 5 and 6 are determined by X-ray studies.     

Gallium tri-chloride derivatives of the sterically demanding pyridines 2,6-Ar2C6H3N (Ar = 2,4,6-Me3C6H2 or 2,4,6-Pr3C6H2)

The sterically demanding pyridines 2,6-Ar₂C₆H₃N [Ar = 2,4,6-Me₃C₆H₂ (1) or 2,4,6-Prⁱ₃C₆H₂ (2)] were prepared by a palladium catalysed Kumada C–C coupling reaction in high yield. Pyridine 1 reacted with one equivalent of GaCl₃ to afford the tetra-chloro gallate–pyridinium ion pair complex [GaCl₄]⁻[2,6-(2,4,6-Me₃C₆H₂)₂C₆H₃NH]⁺ (3). Contrastingly, pyridine 2 reacted with one equivalent of GaCl₃ to afford the anticipated donor-acceptor complex [GaCl₃{2,6-(2,4,6-Prⁱ₃C₆H₂)₂C₆H₃N}] (4). Complexes 1–4 have been characterised variously by single crystal X-ray diffraction, NMR, CHN, and mass spectrometry.     

Chiral “P-N-P” ligands, (C20H12O2)PN(R)PY2 [R = CHMe2, Y = C6H5, OC6H5, OC6H4-4-Me, OC6H4-4-OMe or OC6H4-4-Bu] and their allyl palladium complexes

Chiral “P-N-P” ligands, (C₂₀H₁₂O₂)PN(R)PY₂ [R = CHMe₂, Y = C₆H₅ (1), OC₆H₅ (2), OC₆H₄-4-Me (3), OC₆H₄-4-OMe (4) or OC₆H₄-4-^tBu (5)] bearing the axially chiral 1,1′-binaphthyl-2,2′-dioxy moiety have been synthesised. Palladium allyl chemistry of two of these chiral ligands (1 and 2) has been investigated. The structures of isomeric η³-allyl palladium complexes, (R′ = Me or Ph; Y = C₆H₅ or OC₆H₅) have been elucidated by high field two-dimensional NMR spectroscopy. The solid state structure of [Pd(η³-1,3-Ph₂-C₃H₃){κ²-(racemic)-(C₂₀H₁₂O₂)PN(CHMe₂)PPh₂}](PF₆) has been determined by X-ray crystallography. Preliminary investigations show that the diphosphazanes, 1 and 2 function as efficient auxiliary ligands for catalytic allylic alkylation but give rise to only moderate levels of enantiomeric excess.     

Reactions of methyl and ethyl halides with the complexes Ni[P(C2H5)3]4 and Ni(X)[P(C2H5)3]3

The rates of the thermal reaction of the nickel(0) complex Ni[P(C₂H₅)₃]₄ with the alkyl halides CH₃Br, CH₃I in toluene have been compared with those of the reactions of the nickel(I) complexes Ni(X)[P(C₂H₅)₃]₃ (X  Br,I). The organic products from CH₃X are methane and ethane, and those from C₂H₅I are ethane and ethylene. The reactivity of the nickel(I) complexes is 10–20 times less than that of the nickel(0) complex. The result suggest that the first step of the reaction of nickel(0) with CH₃I is the expected oxidative addition of the halide to the metal substrate. The intermediate thus formed decomposes to produce ethane (and small amounts of methane) without further reaction with the organic halide. This mechanism is supported by deuterium-labeling experiments.     

Effect of ligands on the thermolysis of the double complexes [Co(NH3)6]2C2O4[Cu(C2O4)2]2 and [Co(NH3)6]Cl[Cu(C7H4O3)2]

The thermolysis of the complexes [Co(NH₃)₆]₂C₂O₄[Cu(C₂O₄)₂]₂ (I) and [Co(NH₃)₆]Cl[Cu(C₇H₄O₃)₂] (II) in air and hydrogen at 200, 350, and 500°C and the composition and properties of the thermolysis products are considered. The oxidative thermolysis of the complexes yields mixtures of cobalt and copper oxides, including mixed ones. The reductive thermolysis of the complexes yields a Co + Cu bimetallic powder in the case of compound I and a Co + Cu + C powder in the case of compound II. The thermal behavior of the complexes is governed by the nature of the ligand coordinated to the copper atom. The observed data are explicable in terms of the properties of this ligand. The chemistry of the oxidative and reductive thermolysis is discussed. Original Russian Text ? D.P. Domonov, S.I. Pechenyuk, N.L. Mikhailova, A.T. Belyaevskii, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 7, pp. 1104–1110.     

Synthesis and crystal structure of the double cluster [Cp3Fe4(CO)4(C5H4)]2(p-C6H4)

[Cp₄Fe₄(CO)₄] (1) reacts with p-BrC₆H₄Li and MeOH in sequence to afford the functionalized cluster [Cp₃Fe₄(CO)₄(C₅H₄-p-C₆H₄Br)] (2), while the reaction of 2 with n-BuLi and MeOH produces [Cp₂Fe₄(CO)₄(C₅H₄Bu)(C₅H₄-p-C₆H₄Br)] (3). The double cluster [Cp₃Fe₄(CO)₄(C₅H₄)]₂(p-C₆H₄) (4) has been prepared by treatment of [Cp₄Fe₄(CO)₄] with p-C₆H₄Li₂ and MeOH in sequence. The electrochemistry of 2 and 4, as well as the crystal structure of 4 have been investigated.     

Bond energies and thermal decomposition of [Pt(X)(CH3)(P(C2H5)3)2] complexes

The thermal decomposition of the complexes trans-[Pt(X)(CH₃)L₂] (L  P(C₂H₅)₃; X  Cl, Br, I, CN) in decalin at 170 and 200°C affords methane platinum metal and [Pt(X)₂L₂]. The kinetics of the decomposition of the complexes were determined by monitoring the appearance of methane by GLC. The observed first-order rate constant was found to be independent on the nature of the ligand X. The thermal decomposition of the trideuteriomethyl complexes [Pt(X)(CD₃)L₂] (X  I, CN) in decalin-d₁₈ at 170 and 200°C was studied by GLC/MS. The thermolysis affords CD₃H and CD₄ in ratios which are independent of the nature of X and of the temperature used. The mass spectra of the complexes were also examined. A relative scale of platinum-to-methyl bond dissociation energies has been established by measuring the appearance potential of the fragment ion [Pt(X)L₂]⁺ and the ionization energies in the series [Pt(X)(CH₃)L₂]. Ionization potentials and PtCH₃ bond energies show a clear dependence on the nature of X which is not reflected in corresponding changes in the decomposition rates.     

Cis-trihetero-tris-σ-homobenzenes as tridentate ligands - X-ray crystal. Structure analyses of the Co(C6H9N3)2(NO3)3 and Ba(C6H6O3)4(ClO4)2-complexes

According to X-ray crystal structure analyses “cis-benzenetrisimine” ($\text{2}$) and “cis-benzenetrioxide” ($\text{1}$) act as tridentate ligands in their 2:1- and 4:1-complexes $\text{7}$ (Co(C₆H₉N₃)₂(NO₃)₃) and $\text{8}$ (Ba(C₆H₆O₃)₄(ClO₄)₂), resp. The latter is the rare example of an organic complex with the (approximate) T-symmetry.     

Synthesis, characterization, and crystal structures of n-alkyldiorganodithiophosphates RS2P(OC6H4)2

Treatment of KS₂P(OC₆H₄)₂ (1) with five n-alkyl halides afforded the stable n-alkyldithiophosphate compounds RS₂P(OC₆H₄)₂ (2–6). Single crystal X-ray analysis revealed that the PS₂ fragment in 1 displays an isobidentate coordination pattern; compounds 2–4 display a monodentate binding pattern. The crystal packing of title compounds is stabilized by cation-π, weak hydrogen bonding C–H---O, as well as aromatic non-bonded interactions.     

Synthese et etude des complexes [C5H4(CH2)3C5H4]Ti(C5H5)2 presentant un pont entre deux ligands cyclopentadienyles

The complex (di-η⁵-C₅H₄CH₂CH₂CH₂C₅H₄)Ti(η¹-C₅H₅)₂ (I) can be obtained unambiguously starting from the corresponding bridged titanocene dichloride. Attempts to synthesize the isomeric compounds (η⁵-C₅H₅)₂ Ti(di-η¹-C₅H₄-CH₂CH₂CH₂C₅H₄) (I′) by the action of a convenient bridged dianion on (C₅H₅)₂ TiCl₂ afford several compounds, one of them is the complex I. The possibility of interconversion of these complexes by a fluctional process is discussed.     

The structure of the metallated iridium complex [(C8H12)Ir{P(OC6H3Me)(OC6H4Me)2} {P(OCH2)3CMe}]

The crystal structure of [(C₈H₁₂)$\text{Ir{P(OC}$₆H₃Me)(OC₆H₄Me)₂} {P(OCH₂)₃CMe}] has been determined. a 18.32, b 18.98, c 9.35 Å, U 3251 ų, Pn2_1^a, Z = 4, R = 0.048, 2541 observed data.The coordination about the iridium atom is distorted trigonal bipyramidal; the two phosphorus atoms are equatorial, the σ-bonded carbon is axial, and the bidentate cyclooctadiene is bonded axialequatorial. The IrC(axial) bonds are longer than the IrC(equatorial) bonds: 2.22, 2.26; 2.17, 2.19 Å. The IrC(σ) bond length is 2.19 Å, not significantly different from the formally π-bonded C to Ir distances. The IrP lengths of 2.201 and 2.240 Å and the PIrP angle of 108.7° are normal. The longer IrP bond is in the five-membered chelate ring. The inertness to substitution is discussed.     

Synthesis and crystal structures of (C8h8)Nd(C5H9C5H4) (THF)2 and [(C8H8)Gd(C5H9C4H4(THF)][(C8H8)GD(C5H9C5H4(THF)2]

LnCl₃ (Ln=Nd, Gd) reacts with C₅H₉C₅H₄Na (or K₂C₈H₈) in THF (C₅H₉C₅H₄ = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C₅H₉C₅H₄)LnCl₂(THF)_n (orC₈H₈)LnCl₂(THF)_n], which further reacts with K₂C₈H₈ (or C₅H₉C₅H₄Na) in THF to form the litle complexes. If Ln=Nd the complex (C₈H₈)Nd(C₅H₉C₅H₄)(THF)₂ (a) was obtained: when Ln=Gd the 1 : 1 complex [(C₈H₈)Gd(C_%H₉)(THF)][(C₈H₈)Gd(C₅H₉H₄)(THF)₂] (b) was obtained in crystalline form.

The crystal structure analysis shows that in (C₈H₈)Ln(C₅H₉C₅H₄)(THF)₂ (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η⁵), cyclooctatetraenyl (η⁸) and two oxygen atoms from THF are coordinated to Nd³⁺ (or Gd³⁺) with coordination number 10.

The centroid of the cyclopentadienyl ring (Cp′) in C₅H₉C₅H₄ group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd³⁺ (or Gd³⁺). In (C₈H₈)Gd(C₅H₉C₅H₄)(THF), the cyclopentyl-cyclopentadienyl (η⁵), cyclooctatetraenyl (η⁸) and one oxygen atom are coordinated to Gd³⁺ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd³⁺, which is almost in the plane (dev. -0.0144 Å).     

Synthesis and spectral characterization of diorganodiaminosilanes [(ArNH)2SiPhMe] (Ar = 2,6-Pr2C6H3; 2,4,6-Me3C6H2) and lithium silylamide [(2,6-Et2C6H3NLi)(2,6-Et2C6H3NH)SiPh2]

Aminosilanes bearing bulky substituents on nitrogen centers, [(ArNH)₂SiPhMe] (Ar = 2,6-ⁱPr₂C₆H₃ (1), 2,4,6-Me₃C₆H₂ (2)) and half-sandwich lithium silylamide [(2,6-Et₂C₆H₃NLi)(2,6-Et₂C₆H₃NH)SiPh₂] (3) have been prepared and characterized by elemental analysis, IR, EI mass and NMR (¹H and ²⁹Si) spectroscopic studies. The solid state structures of 2 and 3 have been determined by single crystal X-ray diffraction studies. The molecule 2 has a C₁ symmetry due to the steric crowding, and the two N-H protons are approximately trans to each other. The amido nitrogen atoms in 2 show significant deviation from trigonal-planar geometry, and as a result, the observed Si-N bonds are marginally longer than those observed in aminosilanes with planar nitrogen atoms. The molecule 3 exists as discrete dimer with an inversion center. The Li ion in 3 forms intramolecular π-complex with the neighboring aryl (2,6-Et₂C₆H₃) group, to form a half-sandwich lithium silylamide.     

Synthesis and reactions of some triple alkoxo- and thioato-bridged areneruthenium(II) complexes. X-ray structure determination of [Ru2(η-C6H6)2(OMe)3][BPh4]

Reaction of [{Ru(η-arene)Cl₂}₂] (arene = C₆H₆, 1,4-MeC₆H₄CHMe₂) with NaNH₂ in CH₃CN gives a dark oil which upon treatment with ROH/NaBPh₄ (R = Me, Et) gives the triple bridged complexes [Ru₂(η-arene)₂(OR)₃] [BPh₄]. The structure of the benzene complex (R = Me) has been verified by X-ray analysis. The crystals are monoclinic, space group P2₁/n with a 11.725(4), b 15.573(5), c 18.739(2) Å; β 103.29(2)°. These complexes undergo reactions with tertiary phosphines and hydrogen halides. There is also spectroscopic evidence for intermolecular exchange of the bridging alkoxo ligands on mixing pure solutions of the [M₂(arene)₂(OR)₃]⁺ cations (M = Ru, Os). Reaction of [{Ru(η-arene)Cl₂}₂] with Pb(SEt)₂ in CH₃CN gives the analogous [Ru₂(arene)₂(SEt)₃]⁺ cations.     

Synthesis and characterization of (C5H9C9H6)2Yb(THF)2(II) (1) and [(C5H9C5H4)2Yb(THF)]2O2 (2), and ring-opening polymerization of lactones with 1

Reaction of YbI₂ with two equivalents of cyclopentylindenyl lithium (C₅H₉C₉H₆Li) affords ytterbium(II) substituted indenyl complex (C₅H₉C₉H₆)₂Yb(THF)₂ (1) which shows high activity to ring-opening polymerization (ROP) of lactones. The reaction between YbI₂ and cyclopentylcyclopentadienyl sodium (C₅H₉C₅H₄Na) gives complex [(C₅H₉C₅H₄)₂Yb(THF)]₂O₂ (2) in the presence of a trace amount of O₂, the molecular structure of which comprises two (C₅H₉C₅H₄)₂Yb(THF) bridged by an asymmetric O₂ unit. The O₂ unit and ytterbium atoms define a plane that contains a C_i symmetry center.     

Preparation and study of cyclic polynuclear ferrocenes derived from (C6H5)2PCH2CH2Si(CH3)2C5H4Li as a bridging ligand

The synthesis of the potential bridging ligand (C₆H₅)₂PCH₂CH₂Si(CH₃)₂C₅H₄ (3) is described. The ferrocene (6 derived from 3 has been found to form macrocyclic complexes with metal fragments NiCl₂, NiBr₂, and Co₂(CO)₆. Although monomeric, bimetallic products might have been expected based upon the reduced steric demands of ligand 3 relative to an analogous ligand, (C₆H₅)₂PCH₂Si(CH)₃)₂C₅H₄ (1), it appears that the increased flexibility in 3 is the overriding factor leading to a preference for inter- rather than intramolecular coordination of the second phosphine function in 6.     

Synthesis, characterization and biological activities of some new organotin(IV) derivatives: Crystal structure of [(Sn Ph3) (OOCC6H4OH)] and [(SnMe3)2 (OOC)2C6Cl4 (DMSO)2]

Some new organotin(IV) carboxylates 1-3 of 2-hydroxybenzoic acid (L_A) and 4-6 of 2,3,4,5-tetrachloro-6-(methoxycarbonyl) benzoic acid (L_B) have been synthesized, respectively, by the esterification of triorganotin oxide/hydroxide with the corresponding acids in an appropriate mole ratios. Multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn), IR and X-ray crystallographic studies were carried out to elucidate their structures both in solution and in solid state. The X-ray crystallographic data for 3 was recollected at low temperature. The compound 4 was dissolved in DMSO and a new compound 4 · 2DMSO [(SnMe₃)₂(OOC)₂C₆Cl₄(DMSO)₂] was crystallized out. The structure shows that two Sn moieties are attached to the ligand (L_B) through two carboxylic groups. The two molecules of DMSO are coordinated to each of the Sn atoms via oxygen atom to terminate the conventional polymeric chain of trimethyl carboxylates to a discrete molecule, having trigonal bipyramidal geometry around the Sn atoms. Some of the synthesized compounds exhibited significant antifungal activities and have a potential to be used as drugs.