The complexes [RhCl(3 n)(MeCN)(n)(CF(3)triphos)](CF3SO3)(n) (n = 1, 2; CF(3)triphos = MeC[CH2P(m-CF3C6H4)(2)](3)) and [M(MeCN)(3) (CF(3)triphos)](CF3SO3)(n) (M = Ru, n = 2; M = Ir, n = 3) are catalyst precursors for some typical acetalization and transacetalization reactions. The activity of these complexes is higher than those of the corresponding species containing the parent ligand MeC[CH2P(C6H5)(2)](3)(Htriphos). Also the complexes [MCl3(tripod)] (tripod = Htriphos and CF(3)triphos) are active catalysts for the above reactions. The complex [RhCl2(MeCN)(CF(3)triphos)](CF3SO3) catalyzes the acetalization of benzophenone.

A new diphosphine ligand, 2,6-bis(diphenylphosphinoethyl) bromobenzene, was synthesized and two new complexes, [PdBr{(Ph2PCH2CH2)(2)C6H3}] (1) and [PtBr{(Ph2PCH2CH2)(2)C6H3}] (2), were obtained by the oxidative addition reaction of Pd-0(DBA)(2)(DBA is PhHC = CHCOCH = CHPh) and Pt-0(PPh3)(4) with this ligand, respectively. The two complexes were characterized by P-31 NMR, H-1 NMR and X-ray diffraction. The crystallographic data of complex (1) are: space group Pna2(1), a = 16.806(2) Angstrom, b = 18.578(2) Angstrom, c = 9.643(5) Angstrom and these of complex (2) are : space group P2(1)/a, a = 12.364(3) Angstrom, b = 17.676(4) Angstrom, c = 13.672(7) Angstrom, beta = 94.8b(3)degrees.

The characterization of [(PPh3)3IrH3AgH3Ir(PPh3)3](CF3SO3) is reviewed. The structural and spectroscopic properties of [(tripod)MH3M′H3M(tripod)](CF3SO3) (tripod=CH3C(CH2PPh2)3, CH3C(CH2AsPh2)3; M=Rh, Ir; M′=Cu(I), Ag(I), Au(I), Cd(II)) are also reviewed. It is pointed out that (a) in the Cu(I) and Ag(I) species, each trihydride forms one stronger and one weaker MHM′HM interaction, (b) in the Au(I) species the trimetallic units are held together mainly by MAuM bonds and (c) in the Cd(II) species this cation may weakly interact with all six hydrides. Qualitative bonding schemes describing the MHM′HM interactions are presented. The formation and properties of the hydrido-bridged heterobimetallic complexes of the type [(tripod)MH3M′Ln](CF3SO3) (tripod=as above; M=Rh, Ir; M′=Cu(I), Ag(I), Au(I), L=PR3) are summarized. The structural features of the hexametallic complexes [{(CH3C(CH2PPh2)3)MH3M′}3](CF3SO3)3 (M=Rh, Ir; M′=Cu(I), Ag(I), Au(I)) are reviewed.

The X-ray crystal structure of [{(triphos)H(3-x)Ir}(mu-H)(x) {Au(PR3)}][PF6] (triphos = CH3C(CH2PPh2)(3), x = 2) shows that the gold atom builds two almost equal Ir-H-Au bridges with the he'IrH3(triphos)' building block. The Ir-H-Au bridging parameters are typical of three-center-two-electron interactions. The X-ray crystal structure of [{(triphos)H(3-y)Ir}(mu-H)(y) {Au(PR3)}(2)][PF6](2) shows that each gold atom builds two Ir(mu(2)-H)Au bridges with the three hydrides of the 'IrH3(triphos)' building block; one Ir(mu(3)-H)Au-2 bridge is also present (y = 3). The relative positions of the Ir, H, Au and P atoms show that typical three-center-two-electron interactions predominate in this compound, in which there is no direct Au-Au bonding. The neutron diffraction structure of [{(triphos)Ir}(mu-H)(2){Au(PPh3)}(3)][PF6](2) confirms the earlier hypothesis that only two of the three Ir-Au edges are associated with a hydride with formation of Ir(mu(2)-H)Au bridges. The presence or absence of the latter ligand changes the Ir-Au distance only marginally, in contrast to the general trend in hydride clusters. It is shown that the formation of a 'classical' cluster in this set of compounds requires a quadrimetallic unit and the two additional electrons generated by loss of a proton from an Ir-fl bond in the trication [{(triphos)Ir (mu(2)-H)(3){Au(PR3)}(3)}(3+). (C) 2000 Elsevier Science S.A. All rights reserved.

The reaction of the alkali metal salt of several hydrotris(pyrazolyl)borate anions (Tp3R,4R,5R) with RhCl3·3H2O in MeOH gave complexes of the type [Tp3R,4R,5RRhCl2(MeOH)] (Tp3R,4R,5R=TpMe, TpMe2, TpMe,4Me, TpMe2,4Cl, TpiPr and TpiPr,4Br). While the reaction of Na[TpMe2] with [RhCl3(MeCN)3] in MeCN gave [TpMe2RhCl2(PzMe2H)] (18), that of Na[TpCF3,Me] gave [TpCF3,MeRhCl2(MeCN)]. The X-ray crystal structure of 18 (space group P1̄, a=10.949(8), b=11.415(8), c=24.16(2)Å; α=95.40(7), β=91.39(7), γ=115.37(5)°; Z=4, R=0.032, Rw=0.035 for 3813 observed reflections) shows that the rhodium atom has an octahedral geometry. The reaction of Na[TpMe,Ph] with RhCl3·3H2O or [RhCl3(MeCN)3] gave mer-[RhCl3(PzPh,Me)3] while M[TpCF3,CF3] (M=Na or Tl) did not react with either rhodium substrate. The complexes [Tp3R,4R,5RRhCl2(L)] (L=MeOH and MeCN) react with Cl− in CHCl3 forming the corresponding [Tp3R,4R,5RRhCl3]− anions (Tp3R,4R,5R=Tp, TpMe, TpMe2, TpMe2,4Me, TpMe2,4Cl, TpiPr, TpiPr,4Br, TpCF3,Me). The X-ray crystal structure of [PPh4][TpMe2RhCl3] ([PPh4] [25]) (space group P21/c, a=16.301(1), b=9.9830(6), c=26.337(1)Å; β=101.97(3)°; Z=4, R=0.052, Rw=0.060 for 4264 observed reflections) shows octahedral coordination at rhodium. A molecular modeling study using the structural data for 25 indicates that steric interactions between (a) the CF3-substituents in position 5 on the pyrazolylborate and (b) the CF3-substituents in position 3 and the other ligands present in the coordination sphere, may prevent the formation of rhodium(III) complexes with TpCF3,CF3.

The ruthenium(II) complexes [Ru(CF3CO2)2(CF3triphos)], [Ru2(μ-Cl)3(CF3triphos)2]Cl, [RuH(CH3CN)2(CF3triphos)](CF3SO3) and [Ru(CH3CN)3(CF3triphos)](CF3SO3)2 (CF3triphos=CH3C{CH2P(m-CF3C6H4)2}3) were prepared and characterized. The iridium complexes [Ir(COD)(CF3triphos)]+, [IrCl(CO)(CF3triphos)], [Ir(CO)2(CF3triphos)]+, [IrCl3(CF3triphos)] and [IrCl3−n(MeCN)n(CF3triphos)](CF3SO3)n (n=1, 2 and 3) were also prepared and characterized. The coordination chemistries of these two elements with CF3triphos and with the unsubstituted ligand CH3C{CH2P(C6H5)2}3 (Htriphos) are compared. It is shown that, relative to Htriphos, CF3triphos (a) stabilizes the iridium(I) relative to the iridium(III) oxidation state and (b) its cationic complexes are stronger Lewis acids.

The photochemical rearrangement of [Rh(eta(4)-1,5-cod)Tp(Me2)](Tp(Me2) = hydrotris(3,5-dimethylpyrazolyl)-borato, 1,5-cod = cycloocta-1,5-diene) to the new compound [Rh(eta(4)-1,3-cod)Tp(Me2)] (2) is described. The characterization of 2 was carried out using H-1-, C-13-, and Rh-103-HMQC-NMR spectroscopy. Photolysis of 2 is a versatile entry point into the organometallic chemistry of the {RhTp(Me2)} fragment as it can be used to produce a) hydrido-carbonyl ([Rh(CO)H(2)Tp(Me2)]), b) hydrido-phenyl-phosphite ([RhH(Ph)(P(OMe)(3))Tp(Me2)]), and c) ethoxide-hydrido-phosphite ([RhH(OEt)(P(OMe)(3))Tp(Me2)]) complexes.

The new chain-like tritertiary phosphines PhP{CH2CH2P(p-X-C6H4)2}2, (X=F, Me and OMe), phetpX, were prepared and characterized. These ligands react with cis-[RuCl2(DMSO)4] giving equilibrium mixtures of the eclipsed (ec) and staggered (st) isomers of the dinuclear complexes [Ru2(μ-Cl)3(phetpX)2]Cl. The preparation and characterization of the tritertiary phosphines MesP{CH2CH2P(p-X-C6H4)2}2 (Mes=mesityl, X=H and F), mesetpX, is also reported. They react with cis-[RuCl2(DMSO)4] giving equilibrium mixtures of corresponding uninuclear, [RuCl2(mesetpX)], and dinuclear species, st-[Ru2(μ-Cl)3(mesetpX)2]Cl, whose molecularities were established by determining their diffusion coefficients. The dissociation of st-[Ru2(μ-Cl)3(mesetph)2]Cl to [RuCl2(mesetph)] (K=1.8×10−2 mol−1) is endothermic (ΔH=32 kJ mol−1) and favored by entropy (ΔS=75 J mol−1). The complexes ‘RuCl2(pp2)’ (pp2=phetph, and mesetph) react with CO giving fac-[RuCl2(CO)(pp2)] and fac-[RuCl(CO)2(pp2)]Cl as kinetic products. These complexes slowly rearrange to the thermodynamically stable products mer-[RuCl2(CO)(pp2)]. The complexes st-[Ru2(μ-Cl)3(phetpX)2]Cl react with four equivalents of AgCF3SO3 in MeCN giving the corresponding salts [Ru(MeCN)3(phetpX)](CF3SO3)2. Their activities as catalysts for the acetalization of cyclo-hexanone with 1,2-dihydroxyethane and the trans-acetalization of cyclo-hexanone with 2,2-dimethyl-1,3-dioxolane are described.

Photolysis of [Ir(eta(2)-coe)H-2(Tp(Me2))] (1; Tp(Me2)=hydrotris(3,5-dimethylpyrazolyl)borato, coe = (Z)-cyclooctene) in CH,OH gives a mixture of [IrH4(Tp(Me2))] (4) and [Ir(CO)H-2(Tp(Me2))] (5) in a ca. 1 : 1 ratio. Mass-spectral analysis of the distillate of the reaction mixture at the end of the photolysis shows the presence of coe. When pure CD3OD is used as solvent, the deuteride complexes [IrD4(Tp(Me2))] ((D-4)-4) and [Ir(CO)D-2(Tp(Me2))] ((D-2)-5) are obtained. Also the photolysis of [Ir(eta(4)-cod)(Tp(Me2))] (3) (cod = cycloocta-1,5-diene) gives 4 and 5. A key feature of this photoreaction is the intramolecular dehydrogenation of cod with formation of cycloocta-1,3,5-triene, detected by mass spectroscopy at the end of the photolysis. Labeling experiments using CD3OD show that the hydrides in 4 originate from MeOH. When (CH3OH)-C-13 is used as solvent, [Ir((CO)-C-13)H-2(Tp(Me2))] is formed demonstrating that CH,OH is the source of the CO ligand. The observation that the photolysis of both 1 and 3 give the same product mixture is attributed to the formation of a common intermediate, i.e., the coordinatively unsaturated 16e(-) species {IrH2(Tp(Me2))}.

The new tripodal phosphine CH3C{CH2P(m-CF3C6H4)2}3, CF3PPP, was prepared by reacting CH3C(CH2Br)3 with Li+P(m-CF3C6H4)2−, the latter being best obtained by adding Li+NiPr2− to PH(m-CF3C6H4)2. The rhodium complexes [RhCl(CO)(CF3PPP)], [Rh(LL)(CF3PPP)](CF3SO3) (LL = 2 CO or NBD), [RhX3(CF3PPP)], [RhX(MeCN)3(CF3PPP)](CF3SO3)2 (X = H and Cl), [RhCl2(MeCN)(CF3PPP)](CF3SO3) and [Rh(MeCN)3(CF3PPP)](CF3SO3)3 were prepared and characterized. The X-ray crystal structure of [Rh(NBD)(CF3PPP)](CF3SO3) is reported. The lower oxygen sensitivity of the CF3PPP rhodium(I) complexes, relative to the corresponding species with the parent ligand CH3C(CH2PPh2)3, is attributed to the higher effective nuclear charge on the metal centers caused by the presence of the six CF3 substituents on the terdentate phosphine. A similar effect may be responsible for the easier hydrolysis of the CF3PPP-containing, cationic rhodium(III) complexes relative to the corresponding compounds of the parent ligand.

The incoherent contribution to the tunnelling exchange of hydrogen pairs in NbH(3)cp(2) " (cp " = C5H3(Si(CH3)(3))(2)) was investigated by H-1-NMR line-shape analysis and two-dimensional H-1-NMR exchange spectroscopy. The experimental data were analysed by fitting them with simulated one-and two-dimensional spectra, taking into account the coherent and incoherent tunnelling contributions and nuclear cross relaxation. The dissipative exchange process shows an Arrhenius-like temperature dependence with an activation energy E-a = 69(2) kJ mol(-1) over the temperature range 246-341 K.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis and Characterization of the First Mononuclear NiII Phosphorane Imino ComplexLaura Crociani, Francesco Tisato, Fiorenzo Refosco, Giuliano Bandoli, Benedetto Corain, and Luigi M. VenanziView Author Information ICTIMA-C.N.R., C.so Stati Uniti 4, 35020 Padova, Italy Dipartimento di Scienze Farmaceutiche Via Marzolo 5, 35131 Padova, Italy Dipartimento di Chimica Ingegneria Chimica e Materiali, Via Vetoio Coppito Due 67010 L'Aquila, Italy Centro Studio Stabilità Reattività Composti di Coordinazione CNR, Via Marzolo 1, 35131 Padova, Italy ETH Zentrum Laboratorium für Anorganische Chemie Universitästrasse 6 CH-8092 Zürich, Switzerland Cite this: J. Am. Chem. Soc. 1998, 120, 12, 2973–2974Publication Date (Web):March 17, 1998Publication History Received10 November 1997Published online17 March 1998Published inissue 1 April 1998https://doi.org/10.1021/ja9738440Copyright © 1998 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views293Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (94 KB) Get e-AlertsSupporting Info (2)»Supporting Information Supporting Information SUBJECTS:Amines,Cations,Ligands,Mixtures,Particulate matter Get e-Alerts

This chapter contains sections titled: Clathrate Pt6Cl12.0.1C2H5Cl.5.7H2O cis-Bis(benzeneacetomitrile)dichloroplatium(II) trans-Bis(Benzeneacetonitrile)dichloroplatinum(II)

The complexes [(PEt3)2(Ar)Pt(μ-H)PtH(PEt3)2][BPh4] (Ar=Ph,2,4-Me2C6H3, 2,4,6-Me3C6H22) were prepared and characterized. Multinuclear, multidimensional NMR studies of these complexes show that, in solution, (i) they exist in rapidly intercoverting conformers which retainn the bent Pt(μ-H)PtH moieties found in the solid state, (ii) the coordination at each platinum atom is square planar, (iii) the two coordination planes are perpendicular to each other and (iv) the aryl group is perpendicular to the coordination plane of the platinum atom to which it is bonded. The complex [PEt3)2Pt(μ-H)PtH(PEt3)2][BPh4] does not react with C2H4 and CH2:CH·CO2Me. At −60°C or above, [(PEt3)2(Ph)Pt(μ-H)PtH(PEt3)2)][BPh4] reacts with CO giving the platinum(II) cations trans-[PtX(CO)(PEt3)2](Ph)∗ (X=H and Ph), and [PtH(PEt3)3]+ and the platinum(0) carbonyl cluster [Pt4(μ-CO)3)4]. The cluster structure of I(PEt3)2(Ph)·Pt(μ-H)PtH(PEt3)2][BPh4, obtained by neutron diffraction, shows that the Pt-H-Pt bond angle in this cation is 125(1)° indicating that the interaction between these three atoms is weak.

The complexes trans,cis-M(PMe3)2(CO)2(Me)I (M = Fe and Ru, 1a,b) react with bis- and tris(pyrazol-1-yl)methane, in the presence of NaBPh4, affording trans-[M(PMe3)2(CO)(COMe)(pz2-CH2)]BPh4 (2a,b) and trans-[M(PMe3)2(CO)(COMe)(η2-pz3-CH)]BPh4 (3a,b), respectively (pz = pyrazolyl ring). The reactions of 1b with 5,5‘-Me2-pz2-CH2 and 3,5‘-Me2-pz2-CH2 produce trans-[Ru(PMe3)2(CO)(COMe)(5,5‘-Me2-pz2-CH2)]BPh4 (4) and trans-[Ru(PMe3)2(CO)(COMe)(3,5‘-Me2-pz2-CH2)]BPh4 (5), respectively. A mixture of trans,cis-[Ru(PMe3)2(CO)2(η1-3,3‘-Me2-pz2-CH2)(Me)]BPh4 (6) and trans-[Ru(PMe3)2(CO)(COMe)(3,3‘-Me2-pz2-CH2)]BPh4 (7) is obtained from reaction of 1b and 3,3‘-Me2-pz2-CH2. The reactions of 2−7 with nucleophiles either give back the starting complex (Nu = I-) or analogous complexes (Nu = Br- and Cl-) or produce decomposition products of the complexes (Nu = I2, Br2, Cl2, and OMe-). The solid state structures of 2b and 3b were obtained using single-crystal X-ray diffraction. For all complexes, 2−7 as well as complex 8 (a...