2,2′-biimidazole, 2,2′-bibenzimidazole and imidazoles as ligands in cationic rhodium(I) complexes

Summary Cationic rhodium(I) complexes of the type [Rh(diolefin)(L-L)]ClO₄ and [Rh(diolefin)L₂]ClO₄, (diolefin = 1,5-cyclooctadiene, 2,5-norbornadiene and tetrafluorobenzobarrelene; L-L = 2,2-biimidazole, 2,2-bibenzimidazole; L = pyrazole or imidazoles) are described. [Rh(CO)₂(L-L)]-C1O₄ complexes, which can be obtained by reaction of cyclooctadiene derivatives with CO, react with P-donor ligands in equimolar ratios to yield [Rh(CO)(P-donor)(L-L)]ClO₄ monocarbonyl derivatives. The catalytic activity of some of these complexes is considered.     

Tetraazaadamantane derivatives of group VI metal carbonyls

Summary Tetraazaadamantane (taad) reacts with group VI metal hexacarbonyls to give mononuclear (taad)M(CO)₅ (M=Cr, Mo and W) derivatives. Mixed ligand metal tricarbonyls,cis- (L-L)(taad)M(CO)₃ (L-L=o-phenanthroline or 2,2-bipyridine; M=Cr and Mo) have also been synthesised. Bromine or iodine reacts with (taad)M(CO)₅ (M=Cr and Mo) to give [(taad)M(CO)₅X]⁺X^– (X=Br or I). Nitrosyl chloride reacts with (taad)M(CO)₅ at room temperature to yieldmer- (taad)M(CO)₃NOCl while with the mixed (L-L)(taad)-Mo(CO)₃ complex, a mixture of (L-L)Mo(NO)₂Cl₂ and (L-L)Mo(CO)₂NOCl was obtained. An analogous reaction with (L-L)(taad)Cr(CO)₃, gave only (L-L)Cr(NO)₂Cl₂ derivatives. The products have been characterised by elemental analysis, i.r. spectra, conductivity data and magnetic measurements.     

Halogen oxidation of mixed aminetungsten tricarbonyls

Summary Halogen oxidation of mixed aminetungsten tricarbonyls, (L-L.) (amine) (CO)₃ W (L-L. =o-phen or 2,2-bipy; amine = cyclohexylamine, piperidine, morpholine, n-butylamine and n-hexylamine), at ambient temperature resulted in the formation of unusual products (L-L)(amine)(CO)₃ W. nX₂ (X = 1, n = 1; X = Br, n = 2). Their formation has been inferred on the basis of elemental analysis, i.r. and conductivity measurements.     

Die photochemische synthese von μ-(1-2-η:2-3-η-allen)-octacarbonyldimangan(0)

Novel dihydroiridium(III) complexes containing mono- and bi-dentate sulfur ligands have been isolated. The cationic complexes [Ir(COD)L₂]ClO₄ (COD = 1,5-cyclooctadiene, L = tetrahydrothiophene (tht) or trimethylene sulfide (tms); L₂ = (CH₃S)₂(CH₂)₃ (dth)), [Ir(COD)(L-L)]₂(ClO₄)₂ (L-L = 1,4-dithiacyclohexane (dt) or (t-BuS)₂(CH₂)₂ (tmdto)) and [Ir(CO)₂(tmdto)]₂-(ClO₄)₂ react with H₂ to give the corresponding iridium(III) dihydrides: [IrH₂COD)L₂]ClO₄ (Ia: L = tht, Ib: L = tms, Ic: L₂ = dth), [IrH₂(COD)-(L-L)]₂(ClO₄)₂ (IIa: L-L = tmdto, IIb: L-L = dt) and [IrH₂(CO)₂(tmdto)]₂-(ClO₄)₂ (III). The ¹H NMR chemical shifts and ν(IrH) data are discussed.     

Halogen oxidation of mixed amine(tricarbonyl)chromiums

Summary Bromine and iodine oxidation of some mixed amine-(tricarbonyl)chromiums Cr(CO)₃(L-L)(amine) (L-L=o-phen or 2,2-bipy; amine=cyclohexylamine, piperidine and n-butylamine), at ambient temperature lead to the formation of [Cr(CO)₂(L-L)(amine)Br]Br₃ and [Cr(CO)₂(L-L)(amine)I]I complexes which have been characterised by elemental analysis, i.r. spectra, conductivity and magnetic moment measurements.     

Cationic complexes of rhodium(I) with phenanthroline type ligands

Summary Complexes [Rh(COD)(L-L)]ClO₄ are prepared by reaction of [Rh(COD)₂]ClO₄ with the appropriate ligand L-L (4,7-Ph₂Phen, 2,9-Me₂-4,7-Ph₂Phen, 2,9-Me₂Phen or 5,6-Me₂Phen). Treatment of these complexes with carbon monoxide gives [Rh(CO)₂(L-L)]ClO₄. When the carbonylation reaction is performed in the presence of P(4-RC₆H₄)₃, pentacoordinate complexes [Rh(CO)(L-L){P(4-RC₆-H₄)}_{3 2}]ClO₄ (R=Me, H, F or Cl) are formed. The use of [Rh(COD)(L-L)]ClO₄ as homogeneous hydroformylation catalyst precursors was studied (50 atm, 80°C). Under these conditions no hydrogenation of the olefin or of the aldehydes is observed, but isomerisation reactions are significant.     

Reactions of dichlorobis(ditertiaryphosphine)-ruthenium(II) with carbon monoxide: Preparation of dicarbonylbis(ditertiaryphosphine) ruthenium(II) cations

Reactions of RuCl₂(L-L)₂ (L-L = dppm or dppe) with CO and silver salts of non coordinating anions produce [Ru(CO)₂(L-L)₂]X₂ which, once formed, are stable to CO loss. However, the fluxional five coordinate intermediates [Ru(Cl) (L-L)₂]X, which in some cases may contain ion pairs, are sufficiently electrophilic to abstract fluoride ion from [BF₄]^? or to coordinate other ions in solution such as [O₂PF₂]^? formed by hydrolysis of [PF₆]^?. A series of complexes of general formula [Ru(CO)₂ (dppm)₂AgY]X₂ may also be isolated and are shown to contain a dppm ligand bridging ruthenium and silver, the bond between which is reversibly cleaved by nitromethane on the nmr timescale.     

Ionic Platinum(II)–Imidobis(diphenylthiophosphinato) Complexes: Preparation,Structure, and Thermal Behavior

The PPh₂P(S)NHP(S)PPh₂ (dppaS₂) ligand reacts with the starting complexes PtCl₂(L-L) (L-L = Ph₂PCH₂PPh₂), (dppm), Ph₂PCH₂CH₂PPh₂ (dppe), Ph₂PCH₂CH₂CH₂PPh₂ (dppp), and NaClO₄·H₂O. Final products are monomeric complexes, and their formulas are [Pt(L-L)(dppaS₂-H)] [(L-L = dppm(1), dppe(2), dppp(3)]. All of these have been characterized by ¹H, ¹³C^,31{P¹H} NMR, FTIR, and elemental analysis. These complexes were also examined by TGA, DTA, and DSC analysis. Complexes 2 and 3 were crystallographically characterized.     

Monocarbonyl cationic rhodium(I) complexes

Summary The preparations and characterisation of cationic complexes of the type [Rh(CO)(MeCN)(PR₃)₂]ClO₄, [Rh(CO)L(PR₃)₂]ClO₄ (L=py or 2-MeOpy), [Rh(CO)(L-L)(PR₃)₂]ClO₄ (L-L = bipy or phen) and [Rh(CO)(PR₃)₃]ClO₄ with PR₃ = P(p-YC₆H₄)₃ (Y=Cl, F, Me or MeO) are described.     

Ligating properties oftert-phosphine/arsine sulphides or selenides,Part IX. Preparation and spectroscopic studies of copper(I)/copper(II) complexes with bis(—phosphine chalcogenides)

Summary The analytical, molar conductance and spectroscopic studies of new complexes of copper(I) and copper(II) with bis(—phosphine chalcogenides), Ph₂P(E)(CH₂)_n-P(E)Ph₂(L-L) are reported. The complexes are of the types: (a) [CuX(L-L)](X, n, E: Cl, 2–4, Br, 2, S; Cl, Br, 1, Se); (b) [Cu₂X₂(L-L)] (X, n, E: Cl, Br, 2, 3, Se) and (c) [CuCl₂(L-L)] (n, E: 2, 3, S). Possible structures have been derived.     

Reductive nitrosylation of tetraoxometallates—XI. Molybdate hydroxylamine reaction in the presence of cyanide: Synthesis of mono- and dinitrosyl cyan

The new molybdenum cyanonitrosyl complexes, R₂[Mo(NO)(CN)₅]·2H₂O (R = Ph₄P and Bu₄N) and [Mo(NO)(CN)₃(L-L)]·H₂O [L-L =     

Cationic palladium(II) complexes of ferrocenylphosphines as homogeneous hydrogenation catalysts for olefins

Cationic palladium(II) complexes of ferrocenylphosphines [(L-L′)Pd(S)₂][ClO₄]₂ ((L-L′) = Fe(η⁵-C₅H₄P (C₆H₅)₂)₂ 1, or Fe(η⁵-C₅H₅)(η⁵C₅H₃(CHMeNMe₂)P(C₆H₅)₂-1,2) 2a: S=pyridine or dimethylformamide) were prepared and characterized. The derivatives of 2a are effective catalysts for the hydrogenation of simple olefins at 30°C (1 atm H₂). The rate of reduction of styrene depends on the substrate concentration, catalyst concentration and the solvent, and is only slightly inhibited (16%) by the addition of mercury. These observations are conistent with a homogeneous catalytic system.     

Chemistry of μ-hydridobis[pentacarbonylchromium(0)] species. Part III. Redox reactions with mercury(II) compounds and iodine

Summary [Cr₂(CO)₁₀(-H)]^– undergoes ready hydride substitution on reaction with HgX₂ (X = Cl, Br, I or SCN) or with iodine in acetone, yielding [Cr₂(CO)₁₀(-X)]^– complex species which can be converted quantitatively into [Cr(CO)₅X]^– anions by reactions conducted in the presence of an excess of X^–.LCr(CO)₅ and (L-L)Cr(CO)₄ complexes (L = pyridine; L-L = 1,10-phenanthroline or 2,2-bipyridine) are easily prepared by reactions performed in the presence of the L or L-L ligand, respectively.     

Synthesis and reactivity of rhodium(I) complexes of the type Rh(L-L)(CO)[P(OPh)3] and Rh(L-L)[P(OPh)3]2

Summary The carbonyl ligands in the Rh¹ complexes Rh(L-L)(CO)₂ [L-L=anthranilate (AA) orN-phenylanthranilate(FA) ions] are replaced by P(OPh)₃ to form the mono-or disubstituted products, Rh(L-L)(CO)[P(OPh)₃] and Rh(L-L)[P(OPh)₃]₂ respectively depending on the [P(OPh)₃]/[Rh] molar ratio, at room temperature and in air. Under argon at [P(OPh)₃]/[Rh]4 theortho-metallated Rh¹ complex Rh[P(OPh)₃]₃[P(OC₆H₄)-OPh)₂] is formed. The new route forortho-metallated Rh¹ complex synthesis is described.The Rh(AA)(CO)₂ complex was used as a catalyst precursor in hydroformylation of olefins.     

Synthesis and characterization of cyano complexes of oxotungsten(IV) with morpholinomethyl urea and related ligands

The synthesis and characterization of complexes, (Ph₃P)₂NH₂[WO(CN)₃L-L] · 3H₂O and Cs[WO(CN)₃L-L] · H₂O (where L-L = morpholinomethylurea, morpholinomethylthiourea, piperidinomethylurea, piperidinomethylthiourea, pyrrolidinomethylurea, and pyrrolidinomethythiourea) are presented. The complexes have been prepared by the reaction of K₃Na[WO₂(CN)₄] · 6H₂O with morpholinomethylurea and related ligands in aqueous solution around a pH of 7. These have been isolated as bis(triphenylphospine)imminium or cesium salts. The complexes have been characterized by elemental analysis, ℝ, UV-Vis spectra, magnetic susceptibility and conductivity measurements in addition to TGA/DTA The text was submitted by the authors in English.     

Thermal study of ruthenium(II) complexes containing pyridine-2,6-diimines

Thermal behaviors of mono-and binuclear Ru(II)-pydim complexes: [PydimCl₂RuL] (Pydim: pyridine-2,6-diimine; 2: L=NCMe; 3: L=PPh₃) and [PydimCl₂Ru(L-L)RuCl₂Pydim] (4: L-L=pyrazine; 5: L-L=4,4′-bipyridine) have been studied in nitrogen atmosphere using TG/DTG and DTA techniques. The decompositions of complexes occur in stepwise. The values of activation energy, E _a, and reaction order, n of the thermal decomposition were calculated by means of several methods such as Coats-Redfern (CR), MacCallum-Tanner (MT), Horowitz-Metzger (HM), van Krevelen (vK), Madhusudanan-Krishnan-Ninan (MKN) and Wanjun-Yuwen-Hen-Cunxin (WYHC) based on the single heating rate. Most appropriate method was determined for each decomposition step according to the least-squares linear regression.     

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.     

Synthesis of cationic carbonyl complexes of manganese(I) with bidentate ligands

Summary Bidentate ligands can readily replace acetone in thefac-[Mn(CO)₃(chel)(OCMe₂)]⁺ complexes or the perchlorate group fromfac-[Mn(CO)₃(chel)(OClO₃)] yieldingfac-[Mn(CO)₃(chel)(L-L)]⁺ or [{fac-Mn(CO)₃(chel)}₂(L-L)]²⁺ [chel = 1,10-phenanthroline (phen), 2,2-bipyridine (bipy), 1,2-bis(diphenylphosphine)ethane (dpe); L-L = bis(diphenylphosphine)methane (dpm), dpe, 1,4-bis(diphenylphosphine)butane (dpb), succinonitrile (suc), and glutaronitrile (glu)]. Some of these mononuclear complexes are precursors for binuclear complexes which are linked by bridging phosphines or nitriles.     

Reactivity of the Re-NO centre: Proton induced oxidation of Re(NO)2+ to Re(NO)3+. Synthesis and characterisation of some Re(II) thiocyanato-halogenonitrosyl complexes

The Re(NO)²⁺ moiety as [Re(NO)(NCS)₃H₂O]⁻ or [Re(NO)(NCS)₂(L-L)H₂O]· [L-L = phen (1,10-phenanthroline) or bipy (2,2′-bipyridine)] undergoes proton-induced oxidation reaction with HX (X = Cl, Br) to produce a Re(NO)³⁺ moiety. The spectral and physico-chemical data suggest that the anionic complex is 5 coordinate and the neutral one is 6 coordinate with axial NO group and two NCS ligands intrans-equatorial positions. The complex, [Re(NO)(NCS)₂(phen)Br]·H₂O shows complicated magnetic behaviour which is discussed in the paper. The ESR spectrum of this compound shows typical rhenium hyperfines and <g>-tensor anisotropy compatible with the loss of axial symmetry. However, the spectrum of [Re(NO)(NCS)₂Br₂]⁻ quite reasonably shows axial symmetry, other features being grossly comparable to the L-L compounds. The anionic species and the neutral L-L complex show irreversible one-electron oxidation waves at different voltages. This may correspond to a conversion of Re(NO)³⁺ to Re(NO)⁴⁺ in both the cases. Interestingly enough, only the neutral complexes exhibit an irreversible reduction wave due probably to a conversion of Re(NO)³⁺ to Re(NO)²⁺.     

Chemistry of iron complexes. Part V. Electron spin resonance spectra of some iron(III) complexes and X-Ray diffraction (powder) data of iron(II) complexes employing tertiary phosphine/arsine oxides

Summary Electron spin resonance spectra (X-band, 9.3 GHz) of iron(III) chloride complexes with tri-p-tolylarsine oxide (T₃AO), methylenebis(diphenylphosphine oxide) (mdpo) and 1,4-tetramethylenebis(diphenylphosphine oxide) (tmdpo) support their structures as [Fe(L-L)₂Cl₂][FeCl₄] (L-L=mdpo or tmdpo) and [Fe(T₃AO)₂Cl₂(OH₂)₂][FeCl₄]2H₂O. The x-ray powder diffraction patterns of some iron(II) iodide complexes with mdpo, tmdpo, dmdpo, dmdao and tmdao [dmdpo-1,2-dimethylenebis(diphenylphosphine oxide); dmdao and tmdao are the arsine analogs of dmdpo and tmdpo] show that the complexes are crystalline but not isomorphous.