Metallorganische lewissäuren: XXV. Übergangsmetallkomplexe mit o-koordiniertem perrhenat

The O-perrhenato complexes L_nMOReO₃ (L_nM = Re(CO)₅, Rh(PPh₃)₂(CO), Ir(PPh₃)₂(CO), Pt(PPh₃)₂(H), Ru(η⁵-C₅H₅)(PPh₃)₂, Os(PPh₃)₃(CO)(H), Ir(PPh₃)₂(CO)(H)(Cl) have been prepared from the corresponding halogeno compounds with AgReO₄ or NaReO₄, respectively. The spectroscopic data (IR, ¹H NMR) indicate that ReO₄⁻ is a stronger ligand compared to ClO₄⁻, SO₃CF₃⁻ and BF₄⁻.     

Chemistry of a family of semiquinone monochelates of carbonyl ruthenium(II) generated by reacting quinones with hydridic species

The reactions of [Ru(H)(Cl)(CO)(PPh₃)₃] with 3,5-di-tert-butyl-o-benzoquinone (dbq) and 3,4,5,6-tetrachloro-o-benzoquinone (tcq) have afforded the corresponding semiquinone complexes [Ru^II(dbsq)(Cl)(CO)(PPh₃)₂] and [Ru^II(tcsq)(Cl)(CO)(PPh₃)₂], respectively. The reaction of [Ru(H)₂(CO)(PPh₃)₃] with tcq has furnished [Ru^II(tcsq)(H)(CO)(PPh₃)₂]. Structure determination of [Ru(dbsq)(Cl)(CO)(PPh₃)₂] has revealed that it is a model semiquinonoid chelate with two equal C---O lengths ( 1.291(6) and 1.296(6) Å). The complexes are one-electron paramagnetic (1.85μ_B) and their EPR spectra in fluid media display a triplet structure (g2.00) due to superhyperfine coupling with two trans-³¹P atoms (A_iso17 G). The stretching frequency of the CO ligand increases by 20 cm⁻¹ in going from [Ru(dbsq)(Cl)(CO)(PPh₃)₂] to [Ru(tcsq)(Cl)(CO)(PPh₃)₂] consistent with electron withdrawal by chloro substituents. For the same reason the E_1/2 values of the cyclic voltammetric quinone/semiquinone and semiquinone/catechol couples undergo a shift of 500 mV to higher potentials between [Ru(dbsq)(Cl)(CO)(PPh₃)₂] and [Ru(tcsq)(Cl)(CO)(PPh₃)₂].     

Synthesis of chloro-carbonyl derivatives of rhenium,ruthenium, rhodium,iridium and platinum via reaction of the metal atoms with oxalyl chloride

Co-condensation of atoms of Re, Ru, Rh, Ir and Pt with oxalyl chloride gives metal chloro-carbonyl derivatives which may be used as precursors to the compounds [Re(CO)₄Cl]₂, [Ru(PMe₃)₃(CO)Cl₂], α-[Ru(CO)₃Cl(μ-Cl)]₂, [Ru(PPh₃)₂(CO)₂Cl₂], [Rh(CO)₂(μ-Cl)]₂, [Rh(PPh₃)₂COCl], [Ir(PPh₃)(CO)₂Cl₃] and cis-Pt(CO)₂Cl₂. Molybdenum atoms with oxalyl chloride give molybdenum-chloro derivatives.     

COMPLEXES OF HEXATERTIARY PHOSPHINES AND ARSINES AND THEIR REACTION WITH SMALL MOLECULES

Abstract

The synthesis of a new sexadentate ligand, P,P,P′,P′-tetrakis(2-diphenylarsinoethyl)α, α′-diphospha-p-xylene (TDADX) and the preparation of its iridium(I), rhodium(I) and ruthenium (II) complexes are described. When M=Ir and Rh, MCl(CO)(PPh₃)₂ reacts in benzene solution with the ligand TDADX to yield the complexes, [Ir(TDADX)] Cl and Rh₂ Cl₂ (TDADX). RuCl(CO)(PPh₃)₃ Cl reacts with this ligand to yield [RuCl(TDADX)]Cl. Complexes of P,P,P′,P′-tetrakis(2-diphenylphosphinoethyl-α,α-diphospha-p-xylene(TDDX) were also studied for comparison. Molecular hydrogen reacts with the complexes Ir₂ Cl₂ (TDDX), [Ir(TDADX)] Cl and [RuCl(TDADX)] Cl to form the corresponding hydrido complexes. Reaction of molecular oxygen with Rh₂ Cl₂ (TDADX) resulted in the formation of the dioxygen complex. Ir(I), Rh(I) and Ru(II) complexes of TDDX and TDADX react with carbonmonoxide to give mixed ligand carbonyl complexes. The complexes Ir₂ Cl₂ (TDDX), [Ir(TDADX)] Cl, and [RuCl(TDADX)] Cl react with nitric oxide to yield nitrosyl complexes. Infrared spectral data are provided for adducts formed with hydrogen, oxygen, carbon monoxide and nitric oxide.     

The synthesis of thionitrosodimethylamine (Me2NNS) complexes of ruthenium,osmium, and iridium

Neutral hydrido complexes [ML]ClH(PPh₃)₃ ([ML] = Ru(CO), Os(CO) and Ir(Cl)] react with thionitrosodimethylamine, Me₂NNS, to give [ML]ClH-(SNNMe₂)(PPh₃)₂ with H trans to Me₂NNS, while the hydrido cations cis,trans-[[ML]H(SNNMe₂)₂(PPh₃)₂]⁺ are obtained from Me₂NNS and [Ru(NCMe)₂(CO)-(PPh₃)₂]⁺, [OsH(OH₂)(CO)(PPh₃)₃]⁺ and [IrClH(NCMe)₂(PPh₃)₂]⁺, respectively. The coordinatively unsaturated aryl complexes [ML′]Cl(p-tolyl)(PPh₃)₂ ([ML′]Ru(CO), Os(CO) and Os(CS)) coordinate one molecule of Me₂NNS to give [ML′]Cl(p-tolyl)(SNNMe₂)(PPh₃)₂, the chloride ligands of which are labile. Spectroscopic data suggest that in all these complexes the Me₂NNS ligand adopts a η¹(S) coordination mode.     

Low oxidation state ruthenium chemistry : IV. The reactions of M(CO)2(PPh3)3 complexes (M = Fe,Ru) and the hydrogenation and isomerization of alkenes catalyzed by RuL(CO)2(PPh3)2 (L = H2, PPh3)

The complexes M(CO)₂(PPh₃)₃ (I, M = Fe; II, M = Ru) readily react with H₂ at room temperature and atmospheric pressure to give cis-M(H)₂(CO)₂(PPh₃)₂ (III, M = Fe;IV,M = Ru). I reacts with O₂ to give an unstable compound in solution, in a type of reaction known to occur with II which leads to cis-Ru(O₂)(CO)₂(PPh₃)₂(V). Even compound IV reacts with O₂ to give V with displacement of H₂; this reaction has been shown to be reversible and this is the first case where the displacement of H₂ by O₂ and that of O₂ by H₂ at a metal center has been observed. III and IV are reduced to M(CO)₃(PPh₃)₂ by CO with displacement of H₂; Ru(CO)₃- (PPh₃)₂ is also formed by treatment of IV with CO₂, but under higher pressure. Compounds II and IV react with CH₂CHCN to give Ru(CH₂CHCN)(CO)₂- (PPh₃)₂(VI) which reacts with H₂ to reform the hydride IV.cis-Ru(H)₂(CO)₂(PPh₃)₂(IV) has been studied as catalyst in the hydrogenation and isomerization of a series of monoenes and dienes. The catalysts are poisoned by the presence of free triphenylphosphine. On the other hand the ready exchange of H₂ and O₂ on the “Ru(CO)₂(PPh₃)₂” moiety makes IV a catalyst not irreversibly poisoned by the presence of air. It has been found that even Ru(CO)₂(PPh₃)₃(II) acts as a catalyst for the isomerization of hex-1-ene at room temperature under an inert atmosphere.     

The reactions of Ir(CO)Cl(PPh3)2 with HSnPh3

A reinvestigation of the reaction of Ir(CO)Cl(PPh₃)₂, 1 with HSnPh₃ has revealed that the oxidative-addition product Ir(CO)Cl(PPh₃)₂(H)(SnPh₃), 2 has the H and SnPh₃ ligands in cis-related coordination sites. Compound 2 reacts with a second equivalent of HSnPh₃ by a Cl for H ligand exchange to yield the new compound H₂Ir(CO)(SnPh₃)(PPh₃)₂, 3. Compound 3 contains two cis- related hydride ligands. Under an atmosphere of CO, 1 reacts with HSnPh₃ to replace the Cl ligand with SnPh₃ and one of the PPh₃ ligands with a CO ligand and also adds a second equivalent of CO to yield the 5-coordinate complex Ir(CO)₃(SnPh₃)(PPh₃), 4. Compound 4 reacts with HSnPh₃ by loss of CO and oxidative addition of the Sn-H bond to yield the 6-coordinate complex HIr(CO)₂(SnPh₃)₂(PPh₃), 5 that contains two trans-positioned SnPh₃ ligands.     

Synthesis,characterization and anticancer activity of 3-aminopyrazine-2-carboxylic acid transition metal complexes

Synthetic procedures are described that allow access to the new complexes cis-[Mo₂O₅(apc)₂], cis-[WO₂(apc)₂], trans-[UO₂(apc)₂], [Ru(apc)₂(H₂O)₂], [Ru(PPh₃)₂(apc)₂], [Rh(apc)₃], [Rh(PPh₃)₂(apc)₂]ClO₄, [M(apc)₂], [M(PPh₃)₂(apc)]Cl, [M(bpy)(apc)]Cl (M(II) = Pd, Pt), [Pd(bpy)(apc)Cl], [Ag(apc)(H₂O)₂] and [Ir(bpy)(Hapc)₂]Cl₃, where Hapc, is 3-aminopyrazine-2-carboxylic acid. These complexes were characterized by physico-chemical and spectroscopic techniques. Both Hapc and several of its complexes display significant anticancer activity against Ehrlich ascites tumour cells (EAC) in albino mice.     

Transition metal nitrosyl compounds. Part XIV(1). The oxidation of carbon monoxide by nitric oxide using [M(NO)2(PPh3)2]n+ (M=Fe,Ru or Os; n=0. M=Co,Rh or Ir; n=1)

Summary Carbon monoxide reacts with the cationic dinitrosyls [M(NO)₂(PPh₃)₂]⁺ (M = Rh, Ir) under ambient conditions to produce CO₂, N₂O and the tricarbonyl cations, (M(CO)₃(PPh₃)₂]⁺. The cationic tricarbonyls are reconverted into the dinitrosyl reactants on treatment with NO atca. 80°. The Ru(NO)₂(PPh₃)₂ and Os(NO)₂(PPh₃)₂ complexes react similarly with CO but under more vigorous conditions whereas the corresponding dinitrosyls of cobalt and iron do not undergo this reaction under similar conditions. A pentacoordinate dinitrosyl intermediate [M(NO)₂(CO)(PPh₃)₂]ⁿ⁺ is proposed and a mechanism for the catalytic oxidation of CO by NO is presented. Studies of Pt(N₂O₂)PPh₃)₂ establish that a dinitrogcn dioxide intermediate, produced by the coupling of two nitrosyl ligands, is reasonable.     

1,3-diaryltriazenido complexes of ruthenium(I), (II) and (III), and of osmium(III), rhodium(III) and iridium(III)

The synthesis and characterization of the platinum metal—1,3-diaryltriazenido complexes [Ru(ArNNNAr)(CO)₃]₂, [Ru(ArNNNAr)₂]₂, cis-Ru(ArNNNAr)₂(CO)₂, MX₂(ArNNNAr)(PPh₃)₂ (M = Ru, Os; X = Cl, Br) and M′(ArNNNAr)₃ (M′= Ru, Os, Rh and Ir) are reported. Axial ligand substitution in [Ru(ArNNNAr)(CO)₃]₂ and adduct formation by [Ru(ArNNNAr)₂]₂ are described. In contrast to other known Ru(II)/Ru(II) “lantern” molecules, the species [Ru(ArNNNAr)₂]₂ have measured magnetic moments equivalent to ca one unpaired electron per dimer, which are presumably due to population of the spin states σ²π⁴δ²π^*4 and σ²π⁴δ²π^*3σ^*1.     

New nitrosyl(perfluorocarboxylato) complexes of the platinum metals

Perfluorocarboxylic acids (R_FCOOH) (R_F = CF₃,C₂F₅ and (for Rh) C₆F₅) react with the species [M(NO)₂(PPh₃)₂] (M = Ru, Os) and [M′(NO)(PPh₃)₃] (M′ = Rh, Ir) to yield new nitrosyl complexes [Ru(OCOR_F)₃(NO)(PPh₃)₂], [OsH(OCOR_F)₂(NO)(PPh₃)₂], [Os(OCOR_F)(NO)₂(PPh₃)₂][OCOR_F], [Ir(OCOR_F)(NO)(PPh₃)₂][OCOR_F] and [Rh(OCOR_F)₂(NO)(PPh₃)₂].     

Zur kenntnis der chemie der metallcarbonyle und der cyanokomplexe in flüssigem ammoniak : XXVI Über neue carbamoyl-carbonyl-komplexe des mangans

The carbamoylcarbonyl manganese complexes cis-Mn(CO)₄(NH₃)(CONH₂), cis-Mn(CO)₃(PPh₃)(NH₃)(CONH₂) and cis-Mn(CO)₃(PPh₃)₂(CONH₂), which split off water from the -CONH₂ group at different temperatures, are obtained after very short reaction times by the reactions of Mn(CO)₅Cl, Mn(CO)₄(PPh₃)Cl and [Mn(CO)₄(PPh₃)₂]Cl with liquid NH₃. Because of this cleavage the cyanotricarbonyl complexes Mn(CO)₃(NH₃)₂CN or Mn(CO)₃(PPh₃)(NH₃)CN are formed in liquid NH₃ or ether. The properties of these compounds are described and their structures are discussed on the basis of their IR spectra.     

Reaction of alkenyl carbonyl ruthenium(II) complexes with t-butyl isocyanide. Synthesis of η1-acylruthenium(II) complexes by intramolecular CO insertion

Reaction of Ru(CO)Cl(CHCHR)(PPh₃)₂ or Ru(CO)Cl(CHCHR)(PPh₃)₂L (L = py, Me₂Hpz) with 1 equivalent of t-butyl isocyanide gives the alkenyl derivatives Ru(CO)Cl(CHCHR)(PPh₃)₂(t-BuNC). When an excess of isocyanide is used, further reaction results in intramolecular CO insertion to yield η¹-acyl complexes [Ru(COCHCHR) (t-BuNC)₃(PPh₃)₂]Cl. Related complexes were obtained from [Ru(CO)(CHCHR)(MeCN)₂(PPh₃)₂]PF₆ and an excess of isocyanide.     

Hydrosilylation of n- and o-heterocyclic aldehydes in the presence of RhI,RuII, and PdII complexes

The hydrosilylation of 2-formylpyridine, 2-formyl-6-methylpyridine, 2-formylfuran, and 2-formyl-5-methylfuran with triethylsilane in the presence of Rh(PPh₃)₃Cl, Rh(PPh₃)₃(CO)H, Rh(PPh₃)₂(C0)Cl, Ru(PPh₃)₃Cl₂, Ru(PPh₃)₂(CO)₂Cl₂, and Pd(PPh₃)₂Cl₂ was studied. Silyl ethers of the corresponding hetarylcarbinols were obtained in high yields. The formation of products of dehydrocondensation of the silyl ethers is observed in the hydrosilylation of methyl-substituted aldehydes; this process does not occur in the presence of ruthenium complexes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1372–1380, October, 1988.     

The catalytic transformation of nitrosobenzene into azoxy and azobenzene

Nitrosobenzene is converted into azoxybenzene in alcoholic media in the presence of Ru(CO)₃(PPh₃)₂ as catalyst and under an inert atmosphere; Fe(CO)₃(PPh₃)₂ and palladium complexes such as PdL₂Cl₂ (L  PhNO, p-MeC₆H₄NH₂, PPh₃) and Pd₃(CO)₃(PPh₃)₄, are less active as catalysts. Under CO pressure and with Ru(CO)₃(PPh₃)₂ as catalyst, nitrosobenzene is converted into azobenzene and aniline, while azoxybenzene gives azobenzene.     

Synthesis,structure and electrochemical properties of a family of organoruthenium complexes

Reaction of N-(2′-hydroxyphenyl)benzaldimines (abbreviated in general as H₂L-R, where R stands for the para-substituent in the benzaldehyde fragment and H stands for the dissociable hydrogen atoms) with [Ru(PPh₃)₂(CO)₂Cl₂] affords a family of organoruthenium complexes of the type [Ru(PPh₃)₂(CO)(L-R)] where the N-(2′-hydroxyphenyl)benzaldimine ligand is coordinated to the metal center as tridentate C,N,O-donor. Structure of a representative complex has been determined by X-ray crystallography. All the [Ru(PPh₃)₂(CO)(L-R)] complexes are diamagnetic, and show characteristic ¹H NMR signals and moderately intense MLCT transitions in the visible region. Cyclic voltammetry of the [Ru(PPh₃)₂(CO)(L-R)] complexes shows a reversible Ru(II)–Ru(III) oxidation within 0.38–0.68 V versus SCE, followed by an irreversible oxidation of the coordinated benzaldimine ligand within 1.09–1.27 V versus SCE. An irreversible reduction of the coordinated benzaldimine ligand is also observed near −1.1 V versus SCE. Potential of the Ru(II)–Ru(III) oxidation is observed to be sensitive to the nature of para-substituent R.     

Coordination,oligomerisation and transfer hydrogenation of acetylenes by some ruthenium and osmium carboxylates: Crystal and molecular structures of bis(trifluoroacetato)carbonyl-(methanol) bis(triphenylphosphine)ruthenium(II) and (1,4-diphenylbut-1-en-3-yn-2-yl)trifluoroacetato-(carbonyl) bis(triphenylphosphine)ruthenium(II)

The hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] (M = Ru or Os) react with disubstituted acetylenes PhCCPh and PhCCMe to afford vinylic products [M{C(Ph)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] and [M{C(Ph)CHMe}(O₂CCF₃)(CO) (PPh₃)₂]/[M{C(Me)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] respectively. Acidolysis of these products with trifluoroacetic acid in cold ethanol liberates cis-stilbene and cis-PhHCCHMe respectively thus establishing the cis-stereochemistry of the vinylic ligands. The complexes [M(O₂CCF₃)₂(CO)(PPh₃)₂] formed during the acidolysis step undergo facile alcoholysis followed by β-elimination of aldehyde to regenerate the parent hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] and thereby complete a catalytic cycle for the transfer hydrogenation of acetylenes. The molecular structure of the methanol-adduct intermediate, [Ru(O₂CCF₃)₂(MeOH)(CO)(PPh₃)₂] has been determined by X-ray methods and shows that the coordinated methanol is involved in H-bonding with the monodentate trifluoroacetate ligand [MEO-H---OC(O)CF₃; O...O = 2.54 Å]. The hydrides [MH(O₂CCF₃)(CO) (PPh₃)₂]react with 1,4-diphenylbutadiyne to afford the complexes [M{C(CCPh)CHPh} (O₂CCF₃)(CO)(PPh₃)₂]. The ruthenium product, which has also been obtained by treatment of [RuH(O₂CCF₃)(CO)(PPh₃)₂] with phenylacetylene, has been shown by X-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand. The osmium complexes [Os(O₂CCF₃)₂(CO)(PPh₃)₂], [OsH(O₂CCF₃)(CO)(PPh₃)₂] and [Os{C(CCPh)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] all serve as catalysts for the oligomerisation of phenylacetylene. Acetylene reacts with [Ru(O₂CCF₃)₂(CO)(PPh₃)₂] in ethanol to afford the vinyl complex [Ru(CHCH₂)(O₂CCF₃)(CO)(PPh₃)₂].     

Homogeneous multimetallic catalysts: Part 10. Formylation of aryl and alkenyl iodides by palladium—ruthenium bimetallic catalysts

The PdCl₂(PPh₃)₂—Ru₃(CO)₁₂ bimetallic system exhibited higher catalytic activity for the formylation of aryl and alkenyl iodides than PdCl₂(PPh₃)₂ or Ru₃(CO)₁₂ alone. Thus, in the formylation of iodobenzene (at 70 °C for 1.5 h under 50:50 atm of CO:H₂), the yield of benzaldehyde by PdCl₂(PPh₃)₂—Ru₃(CO)₁₂ catalyst (Pd:Ru = 1:2) was about four times as high as that by PdCl₂(PPh₃)₂ alone. Carbonyl complexes of other metals, such as Mn₂(CO)₁₀, Co₂(CO)₈, Cr(CO)₆, Fe(CO)₅, Mo(CO)₆ and W(CO)₆ were ineffective as the second component of the catalyst. To clarify the mechanism of the synergistic effects, the reaction of PdI(CO-p-Tol)(PPh₃)₂ with [HRu₃(CO)₁₁]⁻ or [HRu(CO)₄]⁻, ruthenium hydride species known to be generated under the catalytic formylation conditions, was performed. The reaction rapidly proceeded at 40 °C by dinuclear reductive elimination to form p-tolualdehyde, although the reaction with molecular hydrogen was very slow. These results strongly suggest that the improved catalytic activity of the Pd—Ru system is attributable to the high hydrogenolysis activity of in-situ-generated ruthenium hydride species.     

NATURE OF SELENOCYANATE BONDING IN THE COMPLEXES OF [MM1(NCSe)4] (M=Co,Ni AND M1Zn,Cd, Hg) WITH CERTAIN PYPIDINE DERIVATIVES

Abstract

Complexes of [MM′(NCSe)₄] (M=Co, Ni and M′=Zn, Cd, Hg) with certain ligands(L) viz. 3-cyanopyridine, 3-aminopyridine, nicotinamide and isonicotinic acid hydrazide have been synthesized and characterized. Their molar conductance, magnetic moment, infrared and electronic spectral studies indicate that these complexes are of three types: cationic-anionic viz. [ML₆] (Zn(NCSe)₄), monomeric bridged viz. [(L₄)M(NCSe)₂Cd(SeCN)₂] and polymeric bridged viz. [dbnd](SeCN)₂L₂M(NCSe)₂Hg(SeCN)₂[dbnd]. The softness and hardness of M, M′, -N-(NCSe′) and -Se-(SeCN-) have also been calculated to derive certain conclusions.     

Coordination,Oligomerisation and Transfer Hydrogenation of Acetylenes by Some Ruthenium and Osmium Carboxylato Complexes: Crystal and Molecular Structure of (1,4-Diphenylbut-1-en-3-yn-2-yl)trifluoroacetato(carbonyl) bis(triphenylphosphine)ruthenium(II)

The complexes (MH(O₂CCF₃) (CO) (PPh₃)₂] and (M(O₂CCF₃)₂(CO)(PPh₃)₂] (M = Ru or Os) react with terminal and internal acetylenes to afford oligomerisation and hydrogenation products, respectively, together with vinylic complexes, including the ruthenium species [Ru(C₄HPh₂)(O₂CCF₃)(CO) (PPh₃)₂], which has been shown by x-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand.