Ruthenium and rhodium nitrosyl complexes containing dichalcogenoimidodiphosphinate ligands

Interaction of [Ru(NO)Cl₃(PPh₃)₂] with K[N(R₂PS)₂] in refluxing N,N-dimethylformamide afforded trans-[Ru(NO)Cl{N(R₂PS)₂}₂] (R = Ph (1), Prⁱ (2)). Reaction of [Ru(NO)Cl₃(PPh₃)₂] with K[N(Ph₂PSe)₂] led to formation of a mixture of trans-[Ru(NO)Cl{N(Ph₂PSe)₂}₂] (3) and trans-[Ru(NO)Cl{N(Ph₂PSe)₂}{Ph₂P(Se)NPPh₂}] (4). Reaction of Ru(NO)Cl₃ · xH₂O with K[N(Ph₂PO)₂] afforded cis-[Ru(NO)(Cl){N(Ph₂PO)₂}₂] (5). Treatment of [Rh(NO)Cl₂(PPh₃)₂] with K[N(R₂PQ)₂] gave Rh(NO){N(R₂PQ)₂}₂] (R = Ph, Q = S (6) or Se (7); R = Prⁱ, Q = S (8) or Se (9)). Protonation of 8 with HBF₄ led to formation of trans-[Rh(NO)Cl{HN(Prⁱ₂PS)₂}₂][BF₄]₂ (10). X-ray diffraction studies revealed that the nitrosyl ligands in 2 and 4 are linear, whereas that in 9 is bent with the Rh–N–O bond angle of 125.7(3)°.     

Zirconium and hafnium complexes containing bidentate diarylamido-phosphine ligands

The first examples of mononuclear, structurally characterized triarylphosphine complexes of zirconium and hafnium are reported. The metathetical reactions of MCl4(THF)2 (M = Zr, Hf) with [iPrNP]Li(THF)2 ([iPrNP]- = N-(2-(diphenylphosphino)phenyl)-2,6-diisopropylanilide) or [MeNP]Li(THF)2 ([MeNP]- = N-(2-(diphenylphosphino)phenyl)-2,6-dimethylanilide) in toluene at -35 degrees C produced the corresponding [iPrNP]MCl3(THF) and [MeNP]2MCl2, respectively, in high yield. In contrast, attempts to prepare [MeNP]MCl3(THF) and [iPrNP]2MCl2 led to the concomitant formation of mono- and bis-ligated complexes, from which purification proved rather ineffective. The solution and solid-state structures of [iPrNP]MCl3(THF) and [MeNP]2MCl2 were studied by multinuclear NMR spectroscopy and X-ray crystallography. The geometry of these six-coordinate complexes is best described as a distorted octahedron in which the chloride ligands in [iPrNP]MCl3(THF) adopt a virtually meridional coordination mode whereas those in [MeNP]2MCl2 are trans to each other.     

Neutral,cationic and dicationic seven-coordinate complexes of molybdenum(II) and tungsten(II) containing mono- and bidentate nitrogen donor ligands

Summary The seven-coordinate complexes [MI₂(CO)₃(NCMe)₂] (M=Mo or W) react with two equivalents of L(L=py, 4Me-py, 3Cl-py or 3Br-py) or one equivalent of NN {NN=2,2-bipyridine(bipy), 1,10-phenanthroline(phen), 5,6-dimethyl-1, 10-phenanthroline (5,6-Me₂-1, 10-phen), 5-Nitro-1, 10-phenanthroline (5-NO₂-1, 10-phen) and C₆H₄(o-NH₂)₂ (o-diam) (for M=Mo only)} in CH₂Cl₂ at room temperature to give the substituted products [MI₂(CO)₃L₂] or [MI₂(CO)₃(NN)] (1–17) in high yield. The compounds [MI₂(CO)₃(NCMe)₂] react with two equivalents of NN (for M=W, NN=bipy; for M=Mo, NN=phen) to give the dicationic salts [M(CO)₃(NN)₂]2I(18–19). The compounds [MI₂(CO)₃(NCMe)₂] (M=Mo or W) react with two equivalents of 5,6-Me₂-1, 10-phen to yield the monocationic dicarbonyl compounds [MI(CO)₂(5,6-Me₂-phen)₂]I (20 and21). The dicationic mixed ligand complexes [M(CO)₃(bipy)(5,6-Me₂-phen)]2I (22 and23) are prepared by reacting [MI₂(CO)₃(NCMe)₂] with one equivalent of bipy, followed by anin situ reaction with 5,6-Me₂-1, 10-phen to afford the products22 and23. The complexes (1–23) described in this paper have been characterised by elemental analysis (C, H and N), i.r. spectroscopy and, in selected cases,¹Hn.m.r. spectroscopy. Magnetic susceptibility measurements show the compounds to be diamagnetic.     

Ruthenium carbene complexes containing bidentate and tridentate PO ligands

Treatment of [Ru(CHR)Cl₂(PCy₃)₂] (Cy = cyclohexyl) with Tl[N(Pr₂ⁱPO)₂] and AgL_OEt (L_OEt⁻ = [CpCo{P(O)(OEt)₂}₃]⁻) afforded the Ru carbene complexes [Ru(CHPh)(PCy₃)Cl{N(Pr₂ⁱPO)₂}] (1) and [L_OEtRu(CHR)(PCy₃)Cl] (2), respectively. Chloride abstraction of complex 2 with TlPF₆ in MeCN afforded [L_OEtRu(CHPh)(PCy₃)(MeCN)][PF₆] (3). Complexes 1 and 2 are capable of catalyzing ring-closing metathesis of diethyl 1,2-diallylmalonate. The crystal structure of complex 2 has been determined.     

The reactivity of nitrosyl ruthenium complexes containing polypyridyl ligands

A series of cis nitrosyl complexes containing polypyridyl ligands were prepared and characterized as cis-[RuL(bpy)₂(NO)](PF₆)₃ (L = pyridine, 4-picoline, or 4-acetylpyridine), by elemental analysis, u.v.–vis. and i.r. spectroscopy, and by electrochemical techniques such as cyclic voltammetry, differential pulse voltammetry, spectroelectrochemistry, and coulometry. The complexes exhibit stretching frequencies (NO) at ca. 1950 cm^–1 indicating that nitrosyl group has a sufficiently high degree of nitrosonium ion (NO⁺) character. In non-aqueous solution, the reduction of these complexes induce nitrosyl to nitro conversion. In aqueous solution the reduction product is cis-[RuL(bpy)₂(NH₃)]²⁺ formed by a six electron mechanism. The nitrosyl compounds are susceptible to nucleophilic attack by hydroxide ion. The equilibrium constants were determined.     

Transition metal nitrosyl compounds,Part XXV1 Studies of some nitrosyl complexes of molybdenum and tungsten

Summary On u.v. irradiation, the dinitrosyldithiocarbamato M(NO)₂ (S2 CNR2 )2 (M = Mo or W) complexes are converted quantitatively into the mononitrosyl M(NO)(S₂CNR₂)₃ complexes. The tungsten complex exhibits nonrigid behaviour at high temperatures; the activation energy for this process has been determined and compared to that of the molybdenum analogue. The M(NO)₂ (MeCOCHCOMe)₂ and M(NO)₂ [(O)SCNR₂]₂ compounds have been prepared; these undergo conversion into uncharacterized nitrosyl derivatives upon irradiation. Cationic complexes of the type [M(NO)₂ (MeCN)₄]2+, [M(NO)₂ (MeCN)₃ X]+ and [M(NO)₂ (MeCN)₂ (MeCOCHCOMe)]+ have been prepared and their exchange with CD₃CN studied. Exchange occursvia a dissociative process and is stereospecific for [M(NO)₂ (MeCN)₄ ]2+ (M = Mo or W) and [M(NO)₂ (MeCN)₃ X]+ (M = MO, X = Cl; M = W, X = Br).     

Synthesis and electrochemical studies of heterobinuclear complexes containing copper and molybdenum nitrosyl groups linked by Schiff base ligands

The reaction of [MoCl(NO)T_p ^* = tris(3,5-dimethylpyrazolylborate] with copper Schiff base complexes derived by condensation of one mole each of 2,5-dihydroxybenzaldehyde and salicylaldehyde with α,ω diamines [NH₂(CH₂) _n NH₂, n = 2–4] yields heterobinuclear complexes with two potential redox centres. I.r., electronic and e.s.r. spectroscopic properties of these complexes are described. Cyclic voltammetric data of the base complexes in DMSO reveal that the copper redox centres undergo irreversible one electron reduction at potentials which vary slightly with the polymethylene carbon chain backbone of the Schiff base ligands. Incorporation of [MoCl(NO)T_p ^*]⁺ groups in the copper Schiff base complexes, results to a slight anodic shift (100 mV) in the reduction potential of the copper centre which remains invariant as the polymethylene carbon chain lengthens. Electrochemical data of the heterobinuclear complexes using CH₂Cl₂ and DMSO as solvents indicate the solvent dependence of the reduction potentials of these complexes. In CH₂Cl₂, the reduction potential of the copper centre shifts cathodically by 100 mV, while that of the molybdenum centre shifts anodically by 200 mV. However, accumulated electrochemical data of the heterobinuclear complexes indicate minimal electronic interactions between the copper and molybdenum redox centres. This revised version was published online in June 2006 with corrections to the Cover Date.     

Triphenylphosphineoxide nitrosyl complexes of molybdenum

Summary The tetramethylthiourea (TMTU) complexes of cobalt(II) and nickel(II) halides have been studied in the solid state by electronic, i.r. and far i.r. spectroscopy and magnetochemically. The tetrahedral Co(TMTU)₂X₂ (X = Cl, Br, 1) and Ni(TMTU)₂X₂ (X = Cl, Br) complexes have normal magnetic moments, electronic spectra and crystal field parameters; Ni₂ (TMTU)₃I₄ is diamagnetic. The cobalt complexes have normal (CoX) and (CoX) vibrational frequencies. Ni(TMTU)₂Cl₂ and Ni₂(TMTU)₃I₄ have (NiX) frequencies corresponding to long or bridging Ni-X bonds, while Ni(TMTU)₂Br₂ has normal (NiBr) frequencies for terminal Ni-Br bonds. The (MS) frequencies are similar to those of cobalt(II) and nickel(II) complexes of other thioureas.     

Isocyanide complexes of molybdenum nitrosyl

Reaction of π-cyclopentadienylmolybdenum nitrosyl halide with CNR (R = alkyl) gives [(π-C₅H₅)Mo(NO)X₂(CNR)] (X = Br or I), [Mo(NO)(CNR)₅]X (X = I or PF₆) and [Mo(NO)(CNR)₄I]; treatment of [Mo(NO)(CNR)₅]I with R′NH₂ gives [Mo(NO)(CNR)₄ {C(NHR)(NHR′)}]I or [Mo(NO)(CNR)₄(NH₂R′)]I (R′ = alkyl) depending on temperature.     

Half-sandwich ruthenium complexes of pentafluorobenzenethiolato ligands

A synthetic study of ruthenium complexes containing pentafluorobenzenethiolato ligand is presented. The bis(triphenylphosphine) complex CpRu(PPh₃)₂SC₆F₅ (1) is prepared from CpRu(PPh₃)₂Cl and C₆F₅S⁻ in high yield. This complex is readily reacted with CO gas to give the mixed carbonyl-phosphine complex CpRu(PPh₃)(CO)SC₆F₅ (2) and with NOBF₄ at room temperature to give [CpRu(PPh₃)(NO)SC₆F₅]BF₄ (3). The one-pot reaction of CpRu(PPh₃)₂Cl, dppa ligands, and C₆F₅S⁻ produces CpRu(dppa)SC₆F₅ [dppa = bis(diphenylphosphino)methane: dppm (4); bis(diphenylphosphino)ethane: dppe (5)]. Complexes (1)–(5) have been characterized by spectroscopic techniques (i.r., ¹H-n.m.r., ³¹P-n.m.r.) and by elemental analysis. The X-ray structural analysis of (5) is reported. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Half-sandwich rhodium complexes containing both N-heterocyclic carbene and ortho-carborane-1,2-dithiolate ligands

A new route was used to synthesize half-sandwich rhodium complexes containing both N-heterocyclic carbenes (NHC) and carborane ligands. The rhodium carbene complexes Cp^∗Rh(L)[S₂C₂(B₁₀H₁₀)] (Cp^∗ = pentamethylcyclopentadienyl, L = 1,3-dimethylimidazolin-2-ylidene; 4) can be obtained from the reaction of Cp^∗Rh(L)Cl₂ (2) with Li₂S₂C₂(B₁₀H₁₀) or from the reaction of Cp^∗Rh[S₂C₂(B₁₀H₁₀)] (3) with silver-NHC complex prepared by direct reaction of an imidazolium precursor and Ag₂O. Complexes 2 and 4 were characterized by IR, NMR spectroscopy, element analysis and X-ray structure analyses.     

N-heterocyclic carbenes as ligands in high-valent molybdenum and tungsten complexes

Oxometal complexes of molybdenum and tungsten in high oxidation states from stable adducts with 1,3-dimethylimidazoline-2-ylidene (L) 1. The first ‘carbene’ complexes of molybdenum(VI) [MoO₂Cl(L)₃]Cl (3a) and tungsten(VI) WO₂Cl₂(L)₂ (4b) are reported.     

Solution studies of some technetium complexes containing sulfur ligands

Interactions between technetium and the following series of sulfur ligands are described: 2,5-dimercapto-1,3,4-thiadiazole, 1-methylimidazol-2-thiol, 6,6-dithiodinicotinic acid, 2-amino-6-mercaptopurine and DL--amino-2-thiopheneacetic acid. The complexation reactions have been investigated (species formed,e, stoichiometry, etc.) and the results obtained have been comparatively evaluated with the aim to find relations between structure of the ligands and its complexing activity.     

Half-sandwich cyclopentadienyl rhodium complexes bearing pendant sulfur or oxygen ligands and their catalytic behaviors in ethylene polymerization

Two half-sandwich rhodium complexes with sulfur or oxygen functionalized cyclopentadienyl ligands [η⁵-C₅H₄(CH₂)₂SCH₂CH₃]RhI₂3, {[η⁵-C₅H₄(CH₂)₂OCH₃]RhI₂}₂4 have been synthesized and characterized by IR, ¹H-NMR spectra and Elemental analyses. The molecular structures of complexes 3 and 4 have been determined by X-ray crystallographic analysis. Complexes 3, 4 with a pendent arm on cyclopentadienyl ligand have been tested as catalysts for ethylene and norbornene polymerization in the presence of MAO. Complexes 3 and 4 kept high activities of ca. 10⁶ g PE mol⁻¹ Rh h⁻¹ with morderate molecular weight (M_w ≈ 10⁵ g mol⁻¹) of polyethylene in the ethylene polymerization. Catalytic activities, molecular weights of polyethylene have been investigated under the various reaction conditions.     

Oxo-tricyano complexes of molybdenum(IV) and tungsten(IV) with bidentate Schiff bases

Summary The reaction of [M(CN)₄O(OH₂)]^2– (M = Mo or W) with 2-acetylpyridine and methyl-or butyl-amine in a water-MeOH mixture gave [M(CN)₃O(L-L)]^- (L-L= Schiff base ligand), isolated as [AsPh₄]⁺ salts. The complexes have been characterized by elemental analysis, and electronic, i.r. and¹H-n.m.r. spectroscopy. The Schiff base ligands complex in a bidentate manner through the two nitrogen atoms giving mixed-ligand compounds similarly to 2,2-bipyridyl or 1,10-phenanthroline.On leave from the Faculty of Chemistry, Jagiellonian University, Kraków.     

Di and monocarbonyl complexes of rhodium(I) containing singly charged bidentate ligands

Summary A series of neutral square planar rhodium(I) dicarbonyls containing singly charged bidentate ligands (salicylaldoxime, -benzoinoxime, -furildioxime, -benzildioxime, dimethylglyoxime, cupferron) has been prepared from three sources: (i) tetracarbonyl--dichlorodirhodium(I), (ii) solutions of hydrated rhodium chloride in DMF held under reflux and (iii) a carbonylated solution of hydrated rhodium chloride in boiling absolute alcohol. These dicarbonyls react with triphenylphosphine,-arsine and -stibine to yield monocarbonyl derivatives. The monocarbonyls form 1 : 1 adducts with TCNE. All complexes have been characterized by elemental analysis, i.r. and uv-visible spectra.     

含吡唑配体的VIB金属羰基配合物的合成与电化学性质研究

研究了吡唑类配体与M(CO)6(M=Cr,W)的光化学反应,合成了一系列的含吡唑配体的五羰基铬钨配合物。研究了该类化合物的电化学性质。结果表明：铬系列化合物存在一对准可逆的氧化还原峰,而钨系列化合物只存在一个不可逆的氧化峰,用X射线单晶衍射测定了化合物3,4,5－三甲基吡唑五羰基铬的晶体结构。该晶体为单斜晶系,空间群为P2(1)/m,晶胞参数为a=0.9106(3)nm,b=07627(2)nm,c=0.9637(3)nm,β＝91.855(5)°,V=0.6689(3)nm^3,Z=2,R=0.042,Cr为六配位的变形八面体构型。     

The formation of cobalt(II) halide complexes containing neutral bidentate ligands

Summary Preparation of cobalt(II) halide complexes with neutral bidentate ligands, including 2-pyridyl alkyl ketones, is reported. 2-Pyridyl alkyl ketones act as monodentate or bidentate ligands depending on the reaction solvent used. Tetrahedral complexes are isolated for all potential -donating neutral ligands.trans-Octahedral complexes are formed only if the neutral ligands are strong -donors and -acceptors. The stereochemistry of cobalt(II) halide complexes is discussed in relation to the nature of the neutral ligands.     

Aluminum complexes incorporating bidentate amido phosphine ligands

A series of aluminum complexes supported by o-phenylene-derived amido phosphine ligands, N-(2-diphenylphosphinophenyl)-2,6-dimethylanilide ([Me-NP]-) and N-(2-diphenylphosphinophenyl)-2,6-diisopropylanilide ([iPr-NP]-), have been prepared. The reactions of trialkylaluminum with H[Me-NP] and H[iPr-NP], respectively, in refluxing toluene produced the corresponding dialkyl complexes [Me-NP]AlR(2) and [iPr-NP]AlR(2) (R = Me, Et). Deprotonation of H[Me-NP] with n-BuLi in THF at -35 degrees C followed by addition of AlCl(3) in toluene at -35 degrees C afforded [Me-NP]AlCl(2), which was subsequently reacted with 2 equiv of trimethylsilylmethyllithium in toluene to give [Me-NP]Al(CH(2)SiMe(3))(2). The aluminum complexes were all characterized by (1)H, (13)C, (31)P, and (27)Al NMR spectroscopy. The solid-state structures of monomeric, four-coordinate [Me-NP]AlEt(2) and [iPr-NP]AlMe(2) and five-coordinate [Me-NP]AlCl(2)(THF) were determined by X-ray crystallography. The (1)H NMR studies of [Me-NP]AlEt(2), [Me-NP]Al(CH(2)SiMe(3))(2), and [iPr-NP]AlEt(2) indicate diastereotopic alpha-hydrogen atoms in these molecules. Heteronuclear COSY and NOE experiments suggest that the phosphorus donor in [Me-NP]Al(CH(2)SiMe(3))(2) and [iPr-NP]AlEt(2) is coupled to only one of the diastereotopic alpha-hydrogen atoms that is virtually antiperiplanar with respect to the phosphorus atom.     

Synthesis and characterisation of nonclassical ruthenium hydride complexes containing chelating bidentate and tridentate phosphine ligands

The synthesis and characterisation of nonclassical ruthenium hydride complexes containing bidentate PP and tridentate PCP and PNP pincer-type ligands are described. The mononuclear and dinuclear ruthenium complexes presented have been synthesised in moderate to high yields by the direct hydrogenation route (one-pot synthesis) or in a two-step procedure. In both cases [Ru(cod)(metallyl)(2)] served as a readily available precursor. The influences of the coordination geometry and the ligand framework on the structure, binding, and chemical properties of the M--H(2) fragments were studied by X-ray crystal structure analysis, spectroscopic methods, and reactivity towards N(2), D(2), and deuterated solvents.