The tris(triphenylphosphine)osmium zerovalent complexes Os(CO)2(PPh3)3, .Os(CO)(CNR)(PPh3)3, Os(CO)(CS)(PPh3)3, Os(CS)(cNR)(PPh3)3 and derived compounds

Detailed procedures for the syntheses of Os(CO)₂(PPh₃)₃, Os(CO)(CNR)-(PPh₃)₃ (R = p-tolyl), Os(CO)(CS)(PPh₃)₃ and Os(CS)(CNR)(PPh₃)₃, together with the derived complexes Os(CO)₂(CS)(PPh₃)₂, Os(CO)(CS)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CS)(PPh₃)₂, Os(η²CS₂)(CO)₂-(PPh₃)₂, Os(η²CS₂)(CO)(CS)(PPh₃)₂, Os(η²-CS₂)(CO)(CNR)(PPh₃)₂, Os(η²PhC₂Ph)(CO)₂(PPh₃)₂ and OsH(C2Ph)(CO)₂(PPh₃)₂ are described.     

Synthesis,spectroscopic and structural characterizations of two new complexes of ruthenium with 2-(hydroxymethyl)benzimidazole and 1,10-phenanthroline ligands

The complexes [RuCl(CO)(PPh₃)₂(HBIm)] and [RuH(CO)(PPh₃)₂(1,10-phen)]Cl·H₂O·(CH₃)₂O have been prepared and studied by IR and UV–Vis spectroscopy, and X-ray crystallography. The complexes were prepared in the reactions of [RuHCl(CO)(PPh₃)₃] with 2-(hydroxymethyl)benzimidazole or 1,10-phenanthroline two hydrate in acetone. The electronic spectra of the obtained compounds have been calculated using the TDDFT method. The luminescence properties of these complexes were examined.     

Deprotonierung von Mn2(μ-H)(μ-PR2)(CO)8 (R=Ph,Cy) zur Synthese von Heteronuklearen Mangan—Gold Clustern mit Mn2Aun-Kernen (n = 1 – 3)

Deprotonation of Mn₂(μ-H)(μ-PR₂)(CO)₈ (R = Ph Cy) for Synthesis of Heteronuclear Manganese-Gold Clusters with Mn₂Au_n Cores (n = 1–3) The dimanganese complexes Mn₂(μ-H)(μ-PR₂)(CO)₈ (R = Ph, Cy) have been deprotonated with 1,8-diazabicyclo[5.4.0]undec-7-en (DBU) in tetrahydrofuran solution at 20^°C to give the anions [Mn₂(μ-PR₂)(CO)₈]^?, which were isolated as tetraethylammonium salts. Both dimanganese complexes and the related anions were measured by cyclic voltammetry. The treatment of the aforementioned dimanganese complexes in thf solution with Lir' (R =Me, Ph) and subsequently with PPh₃AuCl gave at 20^°C three types of products: Mn₂(μ-PR₂(CO)₈(AuPPh₃),Mn₂(μ-PR₂)(μ-C(R′)O)(CO)₆-(AuPPh₃)₂ and Mn₂(μ-PR₂)(CO)₆(AuPPh₃)₃. The newly prepared substances were characterized by means of IR-, UV/VIS, ³¹P NMR data. The results of single X-ray analyses showed for the three-membered metal ring compound Mn₂(μ-PPh₂)(CO)₈(AuPPh₃) an uni-fold bridged σ(Mn? Mn) bond length of 306.7(3) pm, the metallatetrahedron complex Mn₂(μ-PPh₃)(μ-C(Ph)O(CO)₆(AuPPh₃)₂ a twofold bridged σ(Mn? Mn) bond length of 300.6(4) pm and the trigonal-bipyramidal cluster Mn₂(μ-Pph₂)(CO)₆(AuPPh₃)₃ an uni-fold bridged π(Mn? Mn) bond length of 274.7(3) pm. The Mn? Au bonds of these substances are accompanyied by semi-bridging CO ligands which are signified through short Au…C contact lengths in the range of 251 to 270 pm. In the substance with the Mn₂Au₂ metallatetrahedron core exists, additionally, such a contact with the acylic C atom of C(Ph)O bridging group of 263.4(18) pm. Such contact lengths were compared for corresponding dimanganese and dirhenium complexes.     

Mono and Bimetallic Complexes of Molybdenum(ii) and Tungsten(ii) Containing 4,4′-Diphenylenecarbonitrile

The complexes [MI₂(CO)₃(NCMe)₂] (M=Mo or W) react in CH₂Cl₂ at room temperature with two equivalents of 4,4'-diphenylenecarbonitrile (dpc) to afford the new seven-coordinate complexes, [MI₂(CO)₃(4,4'-dpc-N)₂] (1 and 2) in good yield. Equimolar quantities of [MI₂(CO)₃(NCMe)₂] and PPh₃ give [MI₂(CO)₃(NCMe)(PPh₃)], which react in situ with 4,4'-dpc to yield the mono-4,4'-diphenylenecarbonitrile complexes, [MI₂(CO)₃(4,4'-dpc-N)(PPh₃)] (3 and 4). Treatment of the bis(alkyne) complexes, [WI₂(CO)(NCMe)(η ²-RC₂R)₂] (R=Me and Ph) with one equivalent of 4,4'-dpc in CH₂Cl₂ at room temperature affords the acetonitrile displaced products, [WI₂(CO)(4,4'-dpc-N)(η ²-RC₂R)₂] (5 and 6). Reaction of equimolar quantities of [WI₂(CO)(NCMe)(η ²-PhC₂Ph)₂] and 2 in CH₂Cl₂ at room temperature gives the 4,4'-dpc-bridged complex, [WI₂(CO){WI₂(CO)₃(4,4'-dpc-N)(4,4'-dpc- N,N')}(η ²-PhC₂Ph)₂] (7) in good yield. Similarly, equimolar amounts of [WI₂(CO)(NCMe)(η ²-RC₂R)₂] (R=Me and Ph) and (4) react in CH₂Cl₂ to afford the bimetallic complexes, [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(PPh₃)}(η ²-RC₂R)₂] (8 and 9). The new bimetallic 4,4'-dpc-bridged alkyne complexes, [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(η ²-MeC₂Me)₂}(η ²-MeC₂Me)₂] [(10), [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(η ²-PhC₂Ph)₂}(η ²-PhC₂Ph)₂] (11) and [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(η ²-MeC₂Me)₂}(η ²-PhC₂Ph)₂] (12) are also described.     

Carbonylation of alkenyl-complexes of ruthenium. The formation of complexes containing,alkene or acyl ligands,and the reaction of the acyl complexes with methanol

The unsaturated complexes RuCl(CO)(RC=CHR′)(PPh₃)₂ react with CO to give the dicarbonyl complexes RuCl(CO)₂(RC=CHR′)(PPh₃)₂ or the η²-acyl complexes RuCl(CO)(O=CC(R)=CHR′)(PPh₃)₂, depending on the R and R′ groups. The RuCl(CO)(O=CC(Me)=CHMe)(PPh₃)₂ complex reacts with methanol to give RuCl(CO)(O₂CC(Me)=CHMe)(PPh₃)₂, which structure has been established by an X-ray diffraction study.     

Activation of thiocyanogen and selenocyanogen by low oxidation state transition metal complexes

Thiocyanogen and selenocyanogen react with Ru(CO)₃(PPh₃)₂ to give respectively the complexes Ru(CO)₂(PPh₃)₂(NCS)₂ and Ru(CO)₂(PPh₃)₂(NCSe)₂. (M—NCS and M—SCN represent N- and S-thiocyanato groups, M—NCSe and M—SeCN represent N- and Se-selenocyanato groups respectively, while M—CNS indicates the bridging coordination mode of thiocyanate.) Only the thiocyanogen reacts with Ru₃(CO)₁₂ giving [Ru(CO)₂(CNS)₂]_n, which dissolves in hot coordinating solvents, such as pyridine, to form Ru(CO)₂(py)₂(NCS)₂. Selenocyanogen is less effective than thiocyanogen in the oxidative addition reactions with rhodium(I) and iridium(I) complexes; in fact selenocyanogen does not react with Rh(CO)(PPh₃)₂Cl while with Ir(CO)(PPh₃)₂Cl the former gives Ir(CO)(PPh₃)₂(SeCN)₂Cl by an equilibrium reaction. The coordination number of the metal and the charge on the complex do not change the bonding mode of the thiocyanate and selenocyanate groups in the iridium(III) complexes; in the Ir(PPh₃)₂ClX₂ and [Ir(Ph₂PC₂H₄PPh₂)₂X₂]⁺ (X = SCN and SeCN) complexes the pseudohalogens are S- and Se-bonded.The complexes trans-M(PPh₃)₂(SeCN)₂ (M = Pd, Pt) have been obtained by reacting M(PPh₃)₄ with selenocyanogen.     

Potential inhibitors of DNA topoisomerase II: ruthenium(II) poly-pyridyl and pyridyl-azine complexes

In search of new DNA probes a series of new mono and binuclear cationic complexes [RuH(CO)(PPh₃)₂(L)]⁺ and [RuH(CO)(PPh₃)₂(-μ-L)RuH(CO)(PPh₃)₂]²⁺ [L=pyridine-2-carbaldehyde azine (paa), p-phenylene-bis(picoline)aldimine (pbp) and p-biphenylene-bis(picoline)aldimine (bbp)] have been synthesized. The reaction products were characterized by microanalyses, spectral (IR, UV-Vis, NMR and ESMS and FAB-MS) and electrochemical studies. Structure of the representative mononuclear complex [RuH(CO)(PPh₃)₂(paa)]BF₄ was crystallographically determined. The crystal packing in the complex [RuH(CO)(PPh₃)₂(paa)]BF₄ is stabilized by intermolecular π-π stacking resulting into a spiral network. Topoisomerase II inhibitory activity of the complexes and a few other related complexes [RuH(CO)(PPh₃)₂(L)]⁺ {L=2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) and 2,3-bis(2-pyridyl)-pyrazine (bppz)} have been examined against filarial parasite Setaria cervi. Absorption titration experiments provided good support for DNA interaction and binding constants have also been calculated which were found in the range 1.2 × 10³-4.01 × 10⁴ M⁻¹.     

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⁻.     

Catalytic and antimicrobial activities of new ruthenium(II) unsymmetrical Schiff base complexes

Hexa-coordinated ruthenium(II) complexes of the type [Ru(CO)(PPh₃)(Z)(L)] [Z = PPh₃, pyridine (py) or piperidine (pip); L = anion of the Schiff base] have been prepared by reacting [RuHCl(CO)(PPh₃)₂(Z)] with tridentate Schiff bases derived by condensing anthranilic acid with acetylacetone, salicylaldehyde, o-vanillin and o-hydroxyacetophenone. The complexes were characterised by analytical and spectral (i.r., electronic, ¹H- and ³¹P-n.m.r.) data, and were found to be effective catalysts for oxidising primary alcohols to aldehydes in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant. The Schiff bases and their ruthenium(II) complexes show growth inhibitory activity against pathogenic fungi Aspergillus flavus, Fusarium oxysporium and Rhizoctonia solani.     

Erratum

The hydrido-thiocarbonyl osmium(II) complexes OsH₂(CS)(PPh₃)₃, OsHCl(CS)(PPh₃)₃, OsH(OClO₃)(CS)(PPh₃)₃, OsHCl(CS)(CNR)(PPh₃)₂ and [OsH(CS)(CO)(PPh₃)₃]⁺, (R = p-tolyl), have been derived from OsCl₂(CS)(PPh₃)₃ and [OsH(CS)(CO)(PPh₃)₃]⁺, the latter can be deprotonated to give the zerolavent complex, Os(CS)(CO)(PPh₃)₃.     

Thiosemicarbazone Complexes of Ruthenium(II) and Rhodium(I) Containing Triphenylphosphine

Several new hexa-coordinated ruthenium(II) and penta-coordinated rhodium(I) complexes of the types [RuCl(CO)(PPh ₃ ) ₂ (TSC)], [RuH(CO)(PPh ₃ ) ₂ (TSC)], and [Rh(PPh ₃ ) ₃ (TSC)] (where TSC = anion of thiosemicarbazone Schiff bases) have been prepared by the reactions of [RuHCl(CO)(PPh ₃ ) ₃ ], [RuH ₂ (CO)(PPh ₃ ) ₃ )], and [RhH(PPh ₃ ) ₄ ] with thiosemicarbazones of 2-furaldehyde (H-FTSC), thiophene-2-carboxaldehyde (H-TCTSC), p-anisaldehyde (H-ATSC), piperonaldehyde (H-PTSC), and cyclohexanone (H-CTSC). All the new complexes obtained have been characterized on the basis of elemental analysis, IR, ¹ H NMR, ³¹ P NMR, and electronic spectral data.     

Electrophilic reactivity of the dienyl ring in carbonylnitrosyl(cyclohexadienyl)manganese cations

A kinetic study is reported for the addition of phosphorus and nitrogen donor nucleophiles to the ring in (cyclohexadienyl)Mn(CO)(NO)L⁺ complexes (2, L = CO, PPh₃) to give cyclohexadiene complexes. It is shown that (i) the Mn(CO)(NO)L⁺ moiety is electronically equivalent to Fe(CO)₂L⁺ for activating a cyclohexadienyl ring and (ii) that a substituent (Me, Ph, CN) at the C(6)-saturated carbon in 2 produces a large steric retardation of the rate of nucleophile addition.     

Antibacterial and luminescent properties of new donor–acceptor ruthenium triphenylphosphine–bipyridinium complexes

The known compounds N-(2,4-dinitrophenyl)-4,4′-bipyridinium (2,4-DNPhQ⁺), N-phenyl-4,4′-bipyridinium (PhQ⁺) and N-(4-acetylphenyl)-4,4′-bipyridinium (4-AcPhQ⁺) have been used to prepare a series of ruthenium complexes of the type [RuCl(CO)(PPh₃)₂(L)] (where, L = 2,4-DNPhQ⁺ or PhQ⁺ or 4-AcPhQ⁺). The latter complexes reacted with sulphur derivative to give [RuCl(CO)(PPh₃)₂(L)(L′)] (where, L′ = thio-9-xanthone). These new ruthenium complexes display intense, visible metal-to-ligand charge-transfer (MLCT) absorptions, due to dπ(Ru) → π*(pyridinium) excitations. The MLCT energy decreases as the acceptor strength increases in the order PhQ⁺ < 4-AcPhQ⁺ < 2,4-DNPhQ⁺. The new ruthenium complexes have been characterized by using standard analytical and spectroscopic techniques. Fluorescence and antibacterial activity of the ligands and appropriate complexes has also been carried out.     

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].     

The synthesis and properties of bis(μ-phenyldiazenido)octacarbonyldimanganese

Phenyldiazenidotrimethylsilane underwent reaction with bromopentacarbonylmanganese to give bis(μ-phenyldiazenido)octacarbonylmanganese. Triphenylphosphine caused fission of the phenyldiazenido bridge to form two mononuclear five coordinate complexes [Mn(CO)₃N₂Ph(PPh₃)] and [Mn(CO)₂N₂Ph-(PPh₃)₂].     

Synthesis,structural characterization,oxygen sensitivity,and antimicrobial activity of ruthenium(II) carbonyl complexes with thiosemicarbazones

[Ru(CO)(PPh₃)₂(η³-O,N³,S-TSC¹)] (1), [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC²)] (2), and [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC³)] (3) have been prepared by reacting [Ru(H)(Cl)(CO)(PPh₃)₃] with the respective thiosemicarbazones TSC¹ (2-hydroxy-3-methoxybenzaldehyde thiosemicarbazone), TSC² (3-hydroxybenzaldehyde thiosemicarbazone), and TSC³ (3,4-dihydroxybenzaldehyde thiosemicarbazone) in a 1?:?1 M ratio in toluene and all of the complexes have been characterized by UV–vis, FT-IR, and ¹H and ³¹P NMR spectroscopy. The spectroscopic studies showed that TSC¹ is coordinated to the central metal as a tridendate ligand coordinating via the azomethine nitrogen (C=N), phenolic oxygen, and sulfur to ruthenium in 1, whereas TSC² and TSC³ are coordinated to ruthenium as a bidentate ligand through azomethine nitrogen (C=N) and sulfur in 2 and 3. Oxygen sensitivities of 1–3 and [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC⁴)] (4), and antimicrobial activities of 1–3 have been determined.     

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.     

A SIMPLE ROUTE FOR SYNTHESES OF TRIHALIDE-BRIDGED CARBONYL DIRUTHENIUM(II,III) COMPLEXES: CRYSTAL AND MOLECULAR STRUCTURE OF ttt-[RuIICl2(CO)2(PPh3)2],[(CO)(AsPh3)2RuII(μ-Cl3)RuIIICl2(AsPh3)] AND ([CO)(PPh3)2RuII(μ-Br3)RuIIIBr2(PPh3)], SPECTROSCOPIES,ELECTROCHEMISTRY AND PROPERTIES

Abstract

The triply halide-bridged binuclear complexes [Ru₂Cl₅(CO)(AsPh₃)₃] (AsPh₃ = triphenylarsine), [Ru₂Cl₅(CO)(PPh₃)₂(AsPh₃)] (PPh₃ = triphenylphosphine), [Ru₂Cl₅(CO)(AsPh₃)₂(PPh₃)], [Ru₂ Br₅(CO)(PPh₃)₃], [Ru₂Cl₅(CO)(P{p-tol}₃)₂(PPh₃)] (P{p-tol}₃ = tri-p-tolylphosphine) and [Ru₂ Br₂Cl₃(PPh₃)₂(AsPh₃)] were prepared from the precursor compounds ttt-[RuX₂(CO)₂(P)₂] (X = Cl or Br) and [RuY₃(P')₂S]·S (Y = Cl or Br; P=PPh₃, AsPh₃ or P{p- tol}₃ and P' = AsPh₃ or PPh₃; S=DMA or MeOH, where DMA = N,N'-dimethylacetamide). The molecular structures of the binuclear complexes [Ru₂Cl₅(CO)(AsPh₃)₃] (P2_1/c), [Ru₂Br₅(CO)(PPh₃)₃] (P2_1/c) and ttt-[RuCl₂(CO)₂(PPh₃)₂] (P1) were determined by X-ray diffraction methods. The complexes are always formed by two Ru atoms bridged through three halide anions, two of which are × type (from the Ru^II precursor) and the other is Y type (from the ruthenium^III precursor) confirming our previously suggested mechanism for obtaining this class of complexes. The Ru^II atom is also coordinated to a carbon monoxide molecule and two P ligands from the ttt-starting isomer whereas the Ru^III atom is bonded to two non-bridging Y halides and one P' molecule. The presence of Ru^III was confirmed by EPR data, a technique that was also useful to suggest the symmetry of the complexes. The absence of intervalence charge-transfer transitions (IT) in the near infrared spectrum confirms that the binuclear complexes have localized valence. The IR spectra of the complexes show; (CO) bands close to 1970 cm^?1 and ν(Ru-Cl) or(Ru-Br) bands at about 230–380 cm^?1 corresponding to halides at terminal or bridged positions. Two widely separated redox processes, Ru^II/Ru^II←Ru^II/Ru^III→Ru^III/Ru^III, were observed by cyclic voltammetry and differential pulse voltammetry.     

Platinum,iridium and rhodium complexes with substituted bis-(diphenylphosphino)methane ligands Ph2PCH(R)PPh2 (R = Me,Ph or SiMe3)

Substituted phosphines of the type Ph₂PCH(R)PPh₂ and their Pt^II complexes [PtX₂{Ph₂PCH(R)PPh₂}] (R = Me, Ph or SiMe₃; X = halide) were prepared. Treatment of [PtCl₂(NCBu^t)₂] with Ph₂PCH(SiMe₃)-PPh₂ gave [PtCl₂(Ph₂PCH₂PPh₂)], while treatment with Ph₂PCH(Ph)PPh₂ gave [Pt{Ph₂PCH(Ph)PPh₂}₂]Cl₂. Reaction of p-MeC₆H₄C≡CLi or PhC≡CLi with [PtX₂{Ph₂PCH(Me)PPh₂}] gave [Pt(C≡CC₆H₄Me-p)₂-{Ph₂PCH(Me)PPh₂}] (X = I) and [Pt{Ph₂PC(Me)PPh₂}₂](X = Cl),while reaction of p-MeC₆H₄C≡CLi with [Pt{Ph₂PCH(Ph)PPh₂}₂]Cl₂ gave [Pt{Ph₂PC(Ph)PPh₂}₂]. The platinum complexes [PtMe₂(dpmMe)] or [Pt(CH₂)₄(dpmMe)] fail to undergo ring-opening on treatment with one equivalent of dpmMe [dpmMe = Ph₂PCH(Me)PPh₂]. Treatment of [Ir(CO)Cl(PPh₃)₂] with two equivalents of dpmMe gave [Ir(CO)(dpmMe)₂]Cl. The PF₆ salt was also prepared. Treatment of [Ir(CO)(dpmMe)₂]Cl with [Cu(C≡CPh)₂], [AgCl(PPh₃)] or [AuCl(PPh₃)] failed to give heterobimetallic complexes. Attempts to prepare the dinuclear rhodium complex [Rh₂(CO)₃(μ-Cl)(dpmMe)₂]BPh₄ using a procedure similar to that employed for an analogous dpm (dpm = Ph₂PCH₂PPh₂) complex were unsuccessful. Instead, the mononuclear complex [Rh(CO)(dpmMe)₂]BPh₄ was obtained. The corresponding chloride and PF₆ salts were also prepared. Attempts to prepare [Rh(CO)(dpmMe)₂]Cl in CHCl₃ gave [RhHCl(dpmMe)₂]Cl. Recrystallization of [Rh(CO)(dpmMe)₂]BPh₄ from CHCl₃/EtOH gave [RhO₂(dpmMe)₂]BPh₄. Treatment of [Rh(CO)₂Cl₂]₂ with one equivalent of dpmMe per Rh atom gave two compounds, [Rh(CO)(dpmMe)₂]Cl and a dinuclear complex that undergoes exchange at room temperature between two formulae: [Rh₂(CO)₂(μ-Cl)(μ-CO)(dpmMe)₂]Cl and [Rh₂(CO)₂-(μ-Cl)(dpmMe)₂]Cl. This revised version was published online in June 2006 with corrections to the Cover Date.     

Mononuclear hydridocarbonyl ruthenium complexes incorporating N2O2 bis-chelating ligands

The reactions of [RuH(CO)Cl(PPh₃)₃] with N,N^′-bis(salicylidine)-hydrazine (H₂bsh) and N,N^′-bis(salicylidine)-p-phenylene diammine (H₂bsp) in presence of KOH in methanol led in the formation of neutral mononuclear complexes with the formulations [RuH(CO)(PPh₃)₂(L)] (LHbsh or Hbsp). These present the first examples where the ligands H₂bsh or H₂bsp provide only two of its available donor sites for interaction with the metal centre. The complexes have been characterized by elemental analyses, FAB-MS, IR, ¹H, ¹³C, ³¹P NMR and electronic spectral studies. Molecular structure of the representative complex [RuH(CO)(PPh₃)₂(Hbsh)] have been determined by single crystal X-ray analysis.