Arene-iridium(I) complexes. Crystal structure of [Ir(Me3TFB)(C6Me6)]ClO4

The crystal structure of [Ir(Me₃TFB)(C₆Me₆)]ClO₄ has been determined by X-ray diffraction. Lattice constants are a 16.9092(7), b 17.7120(7), c 16.8635(6) Å and β 97.984(3)° in a C2/c monoclinic lattice. The agreement factors are R, 0.038 and R_w 0.048 for the 3321 reflexions with I > 3σ(I). The coordination characteristics are similar to those of the corresponding rhodium analogues.     

Barreleneiridium(I) complexes. Crystal structures of [Ir(Me3TFB)(η6-C6H4Me2)]ClO4 and [Ir(TFB)(η5-PhNPh2)]BF4·CH2Cl2 (TFB = tetrafluorobenzobarrelene)

A new series of cationic areneiridium(I) complexes of formula [Ir(barrelene)(arene)]⁺ or [Ir(barrelene)(PhNRPh)]⁺ (R= Ph or H) have been synthesized from neutral iridium complexes of the type [IrY(barrelene)]_x (barrelene = Me₃TFB, Y = Cl or OMe (x = 2), Y = acac (x = 1); barrelene = TFB, Y = OMe (x = 2), Y = acac (x = 1)). The crystal structures of [Ir(Me₃TFB)(1,4-C₆H₄Me₂)]ClO₄ and [Ir(TFB)(PhNPh₂)]BF₄·CH₂Cl₂ have been determined by X-ray diffraction. They crystallize in the space groups Pbca and Pna2₁ respectively with lattice constants of 17.6947(11), 15.8072(10), 16.0019(11) Å and 9.8059(2), 20.8097(9), 14.3367(4) Å. Final R factors were 0.063 and 0.042 for the observed data. Both complexes show a staggered arrangement between the arene and the TFB moieties and deviation from planarity of the coordinated arene ligands. In the second complex the IrC and NC distances, the CNC angle, the type of arene puckering, and the spectroscopic data indicate a distortion of the coordinated arene towards a η⁵-coordinated iminocyclohexadienyl form.     

Cationic rhodium tetrafluorobenzobarrelene complexes with diolefin or arene ligands,crystal structures of [Rh(TFB)(arene)] ClO4, (arene = C6Me6, C6H3Me3, C6H4Me2)

The preparation and properties of complexes of the general formulae [Rh(TFB)(diolefin)]ClO₄, [Rh(TFB)(arene)]ClO₄ and [Rh(TFB)L₂]ClO₄, (TFB = tetrafluorobenzobarrelene, L = dimethylsulfoxide and tetrahydrothiophen) are described. The crystal structures of the arene complexes (arene = C₆Me₆, C₆H₃Me₃ and C₆H₄Me₂) have been solved by X-ray methods. The three compounds crystallize in quite similar lattices: R3c, a = b = 27.122, 26.233, 25.731 and c = 17.079, 16.388, 16.256 Å, respectively. δR-plots for about 2000 reflections show the agreement in the refinements carried out up to R-values of 5%, 5% and 4% respectively. The Rh atom is coordinated to the double bonds of the TFB and to the arene ring in all three compounds, but the deviation from planarity of the arene and its relative position with respect to the TFB moiety varies.     

Durene-rhodium(I) complexes. Crystal structures of the complexes [Rh(durene)(diolefin)]ClO4 (diolefin  tetrafluorobenzobarrelene or trimethyltetrafluorobenzobarrelene)

The crystal structures of [Rh(durene)(diolefin)ClO₄ (diolefin  tetrafluorobenzobarrelene (TFB) and trimethyltetrafluorobenzobarrelene (Me₃TFB)) have been solved by standard X-ray single crystal methods. The compounds crystallize in the space groups R₃c for the unmethylated TFB compound and P2₁/n for the methylated one. The cell dimensions are 25.7586(5), 17.0059(4) Å and 12.6686(6), 11.5565(3), 16.7269(8) Å, β  104.023(5)°, respectively. The refinement was taken to R values of 0.04 and 0.06, respectively. The arene in the TFB derivative has a distorted inverted boat conformation which becomes a skew one in the Me₃TFB compound. These puckering seems to be related to the tendency of rhodium(I) to achieve square-planar coordination.     

Crystal structures of [Rh(η-C5H5)(C3S5)] and [Rh(η-C5Me5)(C3S5)]2 and properties of their oxidized species

[Rh(η⁵-C₅H₅)(C₃S₅)] and [Rh(η⁵-C₅Me₅)(C₃S₅)]₂ [C₃S₅²⁻=4,5-disulfanyl-1,3-dithiole-2-thionate(2-)] were prepared by reactions of [NMe₄]₂[C₃S₅] with [Rh(η⁵-C₅H₅)Cl₂]₂ and [Rh(η⁵-C₅Me₅)Cl₂]₂, respectively. Their X-ray crystal structural analyses revealed a monomeric form for the former complex and a dimeric geometry containing bridging S-Rh-S bonds for the latter in the solid state. They were reacted with bromine to afford [RhBr(L)(C₃S₅)] (L=η⁵-C₅H₅ and η⁵-C₅Me₅) with the Rh-Br bond and one electron-oxidation on the C₃S₅ ligand. ESR spectra and spin densities for these oxidized species are discussed.     

Duroquinonerhodium(I) complexes. Crystal structure of [Rh(DQ)(C6H5Me)]PF6

The preparation of cationic arenerhodiiim(I) complexes of the type [Rh(DQ)-(arene)]PF₆ (DQ = duroquinone; arene = C₆H_6-nMe_n, n duroquinone complexes with Group VB donor ligands are described. The crystal structure of [Rh(DQ)(C₆H₅Me)]PF₆ has been determined by X-ray diffraction. The compound crystallizes in the P2₁/n space group, in a unit cell of dimensions a 15.9866(5), b 11.8438(3), c 9.9968(3) Å, β 98.473(4)Å. The structure was solved by Patterson and Fourier methods and refined to R and R_w values of 0.062 and 0.076, respectively. The Rh atom is coordinated to a toluene group (η⁶) and a duroquinone ligand (η⁴), which eclipse each other. Both ligands are distorted to adopt boat-like conformations.     

Synthesis and structure of ansa-cyclopentadienyl pyrrolyl titanium complexes: [(η-C5H4)CH2(2-C4H3N)]Ti(NMe2)2 and [1,3-{CH2(2-C4H3N)}2(η-C5H3)]Ti(NMe2)

Reaction of ansa-cyclopentadienyl pyrrolyl ligand (C₅H₅)CH₂(2-C₄H₃NH) (2) with Ti(NMe₂)₄ affords bis(dimethylamido)titanium complex [(η⁵-C₅H₄)CH₂(2-C₄H₃N)]Ti(NMe₂)₂ (3) via amine elimination. A cyclopentadiene ligand with two pendant pyrrolyl arms, a mixture of 1,3- and 1,4-{CH₂(2-C₄H₃NH)}₂C₅H₄ (4), undergoes an analogous reaction with Ti(NMe₂)₄ to give [1,3-{CH₂(2-C₄H₃N)}₂(η⁵-C₅H₃)]Ti(NMe₂) (5). Molecular structures of 3 and 5 have been determined by single crystal X-ray diffraction studies.     

Rhodium(I) complexes with bis(pyrazolyl)methane ligands. Crystal structure of [Rh(COD)(CH2(Pz)2)]ClO4·12 C2H4Cl2

The synthesis and properties of neutral and cationic complexes of general formulae [{RhCl(diolefin)}₂(CH₂(pz)₂)], [Rh(CO)₂ (CH₂(pz)₂)][RhCl₂(CO)₂], (Rh(diolefin)(CH₂(pz)₂)]ClO₂, [{Rh(diolefin)(PPh₃)}₂(CH₂(pz)₂)](ClO₄)₂, [Rh(CO)₂(CH₂(pz)₂)]ClO₄ and [Rh(CO)(CH₂(pz)₂)(PPh₃)]ClO₄ are described. The NMR spectra of [Rh(COD)(CH₂(pz)₂)]ClO₄ complexes are discussed. X-ray structural analysis of [Rh(COD)(CH₂(Pz)₂)]ClO₄ · $\text{1}\text{2}$C₂H₄Cl₂ is presented; the final R factor is 0.061 for 2436 observed data, recorded with Cu-K_α, not corrected for absorption and with the sample inside a capillary. The Rh atom presents a distorted square planar coordination in a mononuclear arrangement. The COD ring has a twisted boat conformation, and the two halves of the CH₂(Pz)₂ moiety, which are quite similar to one another, form an angle of 47.2(4)°.     

Synthesis and reactions of binuclear diolefin rhodium(I) compounds bridged by nitrogen heterocycles. Crystal structure of dichloro-di-1,5-cyclooctadiene(μ-pyrazine)-dirhodium(I) [{Rh(1,5-C8H12)Cl}2(μ-C4H4N2)]

Binuclear complexes of rhodium(I) of the type [(dien)(X)Rh(μ-N-N)Rh(X)(dien)] (dien = 1,5-cyclooctadiene or norbornadiene; N-N = pyrazine, 4,4′-bipyridine or Phenazine and X = Cl or Br) with bridging heterocycles have been isolated and their reactions with carbon monoxide, 2,2′-bipyridine and 1,10-phenanthroline investigated. The crystal structure of [(COD)(Cl)Rh(μ-pyrazine)Rh(Cl)(COD)] has been determined.     

Synthesis and characterisation of two novel Rh(I) carbene complexes: Crystal structure of [Rh(acac)(CO)(L1)]

The [Rh(acac)(CO)(L)] (acac = acetylacetonato; L₁ = 1,3-bis-(2,6-diisopropylphenyl)imidazolinylidene and L₂ = 1,3-bis-(2,4,6-trimethylphenyl)imidazolinylidene) complexes were prepared by the action of the parent carbene on [Rh(acac)(CO)₂] in THF. The crystal structure characterisation of [Rh(acac)(CO)(L₁)] revealed a slightly distorted square planar geometry with the carbene ligand orientated almost perpendicular to the equatorial plane; an elongated trans Rh-O bond of 2.0806(18) Å reflecting the considerable trans-influence of the carbene ligand. By measuring the CO stretching frequencies in a range of [Rh(acac)(CO)(L)] complexes (L = CO, L₁, L₂, PPh₃, PⁿBu₃, P(O-2,4-^tBu₂-Ph)₃) the following electron donating ability series was established: L₁ ∼ L₂ ∼ PⁿBu₃ > PPh₃ > P(O-2,4-^tBu₂-Ph)₃ > CO; indicating the carbenes investigated in this study to have a similar electronic cis-influence as trialkyl phosphines. Both complexes do not display hydroformylation activity towards 1-hexene in the absence of added phosphine or phosphite ligands under the conditions investigated (P = 60; T = 85 °C). In the presence of a phosphine or phosphite ligand the resulting hydroformylation catalysis was identical to that observed for [Rh(acac)(CO)₂] and the corresponding ligand and subsequent high-pressure ³¹P NMR studies confirmed substitution of the carbene ligand under these conditions.     

Crystal structure of [Mn(1,10-C12H8N2)3](B6H7)2

A new compound [MN^II(Phen)₃]²⁺(B₆H₇)₂⁻ is synthesized; its crystal structure is studied by XRD at 100 K. Crystallographic data: C₃₆H₃₈B₁₂N₆Mn, M = 739.39, triclinic symmetry, space group P , unit cell parameters: a = 10.3131(3) ?, b = 13.4839(4) ?, c = 15.1132(4) ?; α = 97.696(1)°, β = 108.324(1)°, γ = 102.211(1)°; V = 1903.9(1) ?³, Z = 2, d _calc = 1.290 g/cm³. The structure is solved by direct and Fourier methods and refined by full-matrix LSM in the anisotropic (isotropic for hydrogen atoms) approximation to the final factor R ₁ = 0.036 for 10169 I _hkl ≥ 2σ _I (Bruker-Nonius X8 APEX CCD diffractometer, λMoK _α). The structure contains two crystallographically different anions. Original Russian Text Copyright ? 2009 by T. M. Polyanskaya, M. K. Drozdova, V. V. Volkov, and K. G. Myakishev __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 381–385, March–April, 2009.     

Trichlorostannato(diphosphine)rhodium(I) complexes. Crystal structure of [Rh(SnCl3)(1,5-cyclooctadiene)(dppp)]

The molecular structure of [Rh(SnCl₃)(1,5-cyclooctadiene)(dppp)] [dppp = 1,3-bis(diphenylphosphino)propane] has been determined to R_F = 3.6% single-crystal X-ray techniques. The crystal contains two discrete molecules 1 and 2 per asymmetric unit. Molecule 1 is best described as distorted trigonal bipyramidal with the diolefin and the diphosphine occupying both apical and equatorial positions and the SnCl₃ group on an equatorial position, and molecule 2 as distorted square pyramidal with the equatorial positions occupied by the diolefin and the diphosphine, respectively, and the SnCl₃ fragment in the apical position. In solution at room temperature, complexes [Rh(SnCl₃)(COD)(diphosphine)] exhibit tin dissociation and various intramolecular rearrangements.     

Dithiocarbamate complexes of cyclopentadienylcobalt(III), [Co(η-C5H5)(L)(S2CNR2)] (L = ligand)

The reactions of [Co(η-C₅H₅)(L)I₂] with Na[S₂CNR₂] (R = alkyl or phenyl) give [Co(η-C₅H₅)(I)(S₂CNR₂)] (I) when L = CO and [Co(η-C₅H₅)(L)(S₂CNR₂)]I (II) when L is a tertiary phosphine, phosphite or stibine, or organo-isocyanide ligand. In similar reactions [Co(η-C₅H₅)(CO)(C₃F₇)I] gives [Co(η-C₅H₅)(C₃F₇)(S₂CNMe₂)] and [Mn(η-MeC₅H₄)(CO)₂(NO)]PF₆ forms [Mn(η-MeC₅H₄)(NO)(S₂CNR₂)]. The iodide ligands in I may be displaced by L, to give II, or by other ligands such as [CN]^?, [NCS]^?, H₂O or pyridine whilst SnCl₂ converts it to SnCl₂I. The iodide counter-anion in II may be replaced by others to give [BPh₄]^?, [Co(CO)₄]^? or [NO₃]^? salts. However [CN]^? acts differently and displaces (PhO)₃P from [Co(η-C₅H₅){P(OPh)₃}(S₂CNMe)]I to give [Co(η-C₅H₅)(CN)(S₂CNMe₂)] which may be alkylated reversibly by MeI and irreversibly by MeSO₃F to [Co(η-C₅H₅)(CNMe)(S₂CNMe₂)]⁺ salts. Conductivity measurements suggest that solutions of I in donor solvents are partially ionized with the formation of [Co(η-C₅H₅)(solvent)(S₂CNR₂)]⁺ I^? species. The IR and ¹H NMR spectra of the various complexes are reported. They are consistent with pseudo-octahedral “pianostool” molecular structures in which the bidentate dithiocarbamate ligands are coordinated to the metal atoms through both sulphur atoms.     

Pyrazolate thiocarbonylrhodium complexes. X-ray structure of [Rh(μ-3,5-Me2Pz)(CS)(PPh3)]2

The preparation and properties of complexes of general formulae [Rh(CS)-(HL)(PR₃)₂]ClO₄ (HL = pyrazole (HPz), 3-methylpyrazole (H3-MePz), 3,5-dimethylpyrazole (H3,5-Me₂Pz), PR₃ = triphenylphosphine, tricyclohexylphosphine) and [(PR₃)₂(CS)Rh(μ-Pz)AuPPh₃]ClO₄ are reported. Complexes of the first set react with potassium hydroxide to give [Rh(μ-L)(CS)(PPh₃)₂ or RhPz(CS)(PR₃)₂ complexes. The structure of the complex [Rh(3,5-Me₂Pz)(CS)(PPh₃)]₂ has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P2₁/c, with Z = 4 in a unit cell of dimensions a = 12.700(11), b = 17.217(16), c = 23.041(18) Å, β = 116.55(8)°. The structure has been solved by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.059 for 1978 independent reflections. The structure consists of dimeric complexes, in which each rhodium atom is in a square-planar environment being bonded to a carbon atom of a thiocarbonyl ligand, a phosphorus atom of a triphenylphosphine molecule and to two nitrogen atoms of pyrazolate ligands bridging the metal atoms. The dihedral angle of 71.1° between such two square planes leads to a bent configuration with an intramolecular rhodium-rhodium distance of 3.220 Å. The thiocarbonyl and triphenylphosphine ligands are in a trans disposition.     

Synthesis and characterization of the [Cu(Cin2bda)2]ClO4 and [Cu(Ncin2bda)2]ClO4 complexes: Crystal structure of [Cu(Ncin2bda)2]ClO4

Two copper(I) complexes [Cu(Cin₂bda)₂]ClO₄ (I) and [Cu(Ncin₂bda)₂]ClO₄ (II) have been prepared by the reaction of the ligands N²,N²′-bis(3-phenylallylidene)biphenyl-2,2′-diamine (L¹) and N²,N²′-bis[3-(2-nitrophenyl)allylidene]biphenyl-2,2′-diamine (L²) and copper(I) salt. These compounds were characterized by CHN analyses, ¹H NMR, IR, and UV-Vis spectroscopy. The C=N stretching frequency in the copper(I) complexes shows a shift to a lower frequency relative to the free ligand due to the coordination of the nitrogen atoms. The crystal and molecular structure of II was determined by X-ray single-crystal crystallography. The coordination polyhedron about the copper(I) center in the complex is best described as a distorted tetrahedron. A quasireversible redox behavior was observed for complexes I and II. The article is published in the original.     

1,4-Cycloaddition of pyrazole with mesityl oxide; solid-state structure of bicyclic [C6H5Me3N2(OH)]Cl

The synthesis of bicyclic 6-hydroxy-6,8,8-dimethyl-5-aza-1-azonia-bicyclo[3.3.0]octa-1,3-diene chloride, [C₆H₅Me₃N₂(OH)]Cl, (5) by the HCl-catalyzed 1,4-cycloaddition of pyrazole (1) with mesityl oxide (4) is described. A proposed mechanism for the formation of 5 will be given.     

Copper(I)---aryl bonds in cluster complexes: The structure of [Cu(2-Me2NH6H4)]4(CuBr)2·1.5C6H6

An X-ray diffraction analysis of [Cu(2-Me₂NC₆H₄)]₄(CuBr)₂·1.5C₆H₆ shows the six copper atoms in a distorted octahedral arrangement; the bromine atoms bridge trans-equatorial edges, the 2-(dimethylamino)phenyl ligands bridging faces so that the complex has approximate C₂ symmetry.     

Synthesis, structure and theoretical study of two rhodium(I) complexes [Rh(TropNMe)(CO)(PPh3)] and [Rh(Trop)(CO)(PPh3)] · Acetone

Rhodium(I) complexes [Rh(TropNMe)(CO)(PPh₃)] (TropNMe = 2-(N-methylamino)tropone, ONC₈H₉) (1) and [Rh(Trop)(CO)(PPh₃)] · Acetone (Trop = Tropolone, O₂C₇H₆) (2) have been synthesized and characterized by single-crystal X-ray diffraction analysis. A distorted square planar geometry about the rhodium(I) metal centre is observed in both compounds 1 and 2. Substitution of an oxygen atom with a methyl functionalized nitrogen atom does not significantly alter the bond distances and angles in the rhodium(I) complex. A theoretical study at B3LYP/6-31G(d) (main group) and LANL2DZ (Rh) level is presented to clarify the solid state behaviour of these complexes.     

Synthesis and crystal structure of the complex [MoW(OEt)(μ-CH2){μ-C(C6H4Me-4)C(Me)O}(η-C7H7)(η-C2B9H10Me)]

The complex [MoW(μ-CC₆H₄Me-4)(CO)₂(η⁷-C₇H₇)(η⁵-C₂B₉H₁₀Me)] reacts with diazomethane in Et₂O containing EtOH to afford the dimetal compound [MoW(OEt)(μ-CH₂){μ-C(C₆H₄Me-4)C(Me)O}(η⁷-C₇H₇)(η⁵-C₂B₉H₁₀Me)]. The structure of this product was established by X-ray diffraction. The Mo---W bond [2.778(4) Å] is bridged by a CH₂ group [μ-C---Mo 2.14(3), μ-C---W 2.02(3) Å] and by a C(C₆H₄Me-4)C(Me)O fragment [Mo---O 2.11(3), W---O 2.18(2), Mo---C(C₆H₄Me-4) 2.41(3), W---C(C₆H₄Me-4) 2.09(3), Mo---C(Me) 2.26(3) Å]. The molybdenum atom is η⁷-coordinated by the C₇H₇ ring and the tungsten atom is η⁵-coordinated by the open pentagonal face of the nido-icosahedral C₂B₉H₁₀Me cage. The tungsten atom also carries a terminally bound OEt group [W---O 1.88(3) Å]. The ¹H and ¹³C-{¹H} NMR data for the dimetal compound are reported and discussed.     

Crystal structure of [Pd(NH3)4][Rh(NH3)(NO2)5]

An XRD analysis is used to study the single crystal of [Pd(NH₃)₄][Rh(NH₃)(NO₂)₅] double complex salt at T = 150(2) K. Crystallographic characteristics are as follows: a = 7.6458(5) ?, b = 9.8813(6) ?, c = 9.5788(7) ?, β = 109.469(2)°, V = 682.30(8) ?³, P2₁/m space group, Z = 2, d _x = 2.553 g/cm³. The geometry of the complex [Rh(NH₃)(NO₂)₅]²⁻ anion is described for the first time: Rh-N(NO₂) distances are 2.020(4)–2.060(3) ?, Rh-N(NH₃) 2.074(4) ?, N(NO₂)-Rh-N(NH₃) trans-angle is 178.8(2)°.